:root{
--bg:#f5f1e7;--surface:#fffdf8;--surface2:#f0ede4;--text:#17231e;--muted:#6a756e;--line:#d7ddd6;
--green:#0f6b57;--green2:#0a4a3d;--amber:#d99632;--amber2:#f2c778;--mint:#dff1e9;--blue:#8eabb8;
--shadow:0 24px 65px rgba(25,40,33,.11);--shadow2:0 10px 28px rgba(25,40,33,.07)
}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;color:var(--text);font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;background:
radial-gradient(circle at 7% -2%,rgba(217,150,50,.16),transparent 25%),
radial-gradient(circle at 93% 8%,rgba(15,107,87,.13),transparent 30%),
linear-gradient(180deg,#fbf8f1 0%,var(--bg) 100%);min-height:100vh}
a{color:inherit}.page{width:min(1450px,calc(100% - 28px));margin:auto;padding:22px 0 68px}
.site-header{display:flex;justify-content:space-between;align-items:center;gap:16px}.brand{display:flex;align-items:center;gap:13px;text-decoration:none}
.brand-name{font-weight:900;letter-spacing:-.03em;font-size:1.18rem}.eyebrow{font-size:.7rem;text-transform:uppercase;letter-spacing:.14em;color:var(--green);font-weight:900}
.header-actions{display:flex;align-items:center;gap:8px}.pill,.theme-button{border:1px solid var(--line);background:rgba(255,253,248,.9);border-radius:999px;color:var(--text)}
.pill{padding:9px 12px;text-decoration:none;font-size:.82rem;font-weight:750}.theme-button{width:40px;height:40px;cursor:pointer}
.language-menu{display:flex;gap:3px;border:1px solid var(--line);background:rgba(255,253,248,.9);border-radius:999px;padding:4px}
.language-menu a{text-decoration:none;font-size:.69rem;font-weight:850;padding:5px 6px;border-radius:999px;color:var(--muted)}.language-menu a.active{background:var(--green);color:#fff}
.lab-logo{position:relative;width:46px;height:50px}.flask-neck{position:absolute;left:17px;top:1px;width:13px;height:17px;border:2px solid var(--green);border-bottom:0;border-radius:4px 4px 0 0}
.flask-body{position:absolute;left:6px;top:16px;width:35px;height:32px;border:2px solid var(--green);border-radius:7px 7px 15px 15px;overflow:hidden;transform:skewX(-4deg)}
.flask-liquid{position:absolute;left:-2px;right:-2px;bottom:-2px;height:15px;background:var(--amber)}.flask-body i,.flask-body b{position:absolute;border-radius:50%;background:var(--green);opacity:.5}
.flask-body i{width:5px;height:5px;left:8px;top:7px}.flask-body b{width:4px;height:4px;right:8px;top:12px}

.hero{display:grid;grid-template-columns:minmax(0,1fr) 310px;gap:30px;align-items:center;padding:58px 0 25px}
.hero h1{font-size:clamp(3rem,6.4vw,6.6rem);line-height:.89;letter-spacing:-.075em;margin:0 0 18px;max-width:1000px}
.hero h1 span{color:var(--green)}.hero p{max-width:760px;color:var(--muted);font-size:1.08rem;line-height:1.7;margin:0}
.hero-lab{height:220px;position:relative}.atom-hero{position:absolute;inset:12px 30px 10px 30px}
.atom-core{position:absolute;left:50%;top:50%;width:44px;height:44px;transform:translate(-50%,-50%);border-radius:50%;background:var(--amber);box-shadow:0 0 0 12px rgba(217,150,50,.12)}
.orbit{position:absolute;left:50%;top:50%;width:175px;height:82px;border:2px solid rgba(15,107,87,.45);border-radius:50%;transform:translate(-50%,-50%) rotate(var(--r));}
.orbit:after{content:"";position:absolute;width:12px;height:12px;border-radius:50%;background:var(--green);right:12px;top:12px}
.orbit.o1{--r:0deg}.orbit.o2{--r:60deg}.orbit.o3{--r:-60deg}

.table-toolbar{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:15px 0}
.search{position:relative;max-width:340px;width:100%}.search input{width:100%;border:1px solid var(--line);background:var(--surface);border-radius:999px;padding:12px 16px 12px 38px;color:var(--text)}
.search:before{content:"⌕";position:absolute;left:14px;top:50%;transform:translateY(-50%);color:var(--muted)}
.legend{display:flex;flex-wrap:wrap;gap:7px}.legend span{font-size:.72rem;color:var(--muted);border:1px solid var(--line);padding:6px 8px;border-radius:999px;background:var(--surface)}

.pt-wrap{overflow-x:auto;padding:8px 2px 18px;scrollbar-width:thin}
.periodic-table{min-width:1120px;display:grid;grid-template-columns:repeat(18,minmax(54px,1fr));grid-auto-rows:76px;gap:6px}
.element{position:relative;text-decoration:none;border:1px solid var(--line);border-radius:14px;padding:7px;background:var(--surface);box-shadow:var(--shadow2);overflow:hidden;transition:.18s ease}
.element:hover{transform:translateY(-3px) scale(1.025);z-index:5;border-color:var(--green);box-shadow:var(--shadow)}
.element .n{font-size:.63rem;color:var(--muted)}.element .s{font-size:1.45rem;line-height:1;font-weight:950;letter-spacing:-.04em;margin-top:5px}.element .nm{font-size:.62rem;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;margin-top:4px}
.element:before{content:"";position:absolute;inset:auto 0 0 0;height:4px;background:var(--accent,var(--green))}
.cat-nonmetal{--accent:#44a87c}.cat-noble_gas{--accent:#6f9fca}.cat-alkali_metal{--accent:#d58d3a}.cat-alkaline_earth_metal{--accent:#d9b45a}.cat-metalloid{--accent:#6eaa9d}.cat-halogen{--accent:#70a65b}.cat-transition_metal{--accent:#a681b0}.cat-post_transition_metal{--accent:#8399a0}.cat-lanthanide{--accent:#58aeb0}.cat-actinide{--accent:#c27b72}.cat-unknown{--accent:#9ba29e}
.f-block{margin-top:8px}.f-title{font-size:.72rem;color:var(--muted);font-weight:850;margin:8px 0}.f-row{min-width:900px;display:grid;grid-template-columns:repeat(15,minmax(54px,1fr));gap:6px}

.home-section{margin-top:28px}.home-section h2{font-size:1.8rem;letter-spacing:-.04em;margin:0 0 14px}
.element-list{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:10px}.list-card{background:var(--surface);border:1px solid var(--line);border-radius:17px;padding:14px;text-decoration:none;display:flex;align-items:center;gap:12px}
.list-symbol{width:42px;height:42px;border-radius:12px;background:var(--mint);display:grid;place-items:center;font-weight:900;color:var(--green)}

.element-hero{display:grid;grid-template-columns:minmax(0,1fr) 360px;gap:30px;align-items:center;padding:52px 0 28px}
.element-title{display:flex;align-items:flex-start;gap:20px}.big-tile{width:115px;height:128px;border:1px solid var(--line);border-radius:25px;background:var(--surface);box-shadow:var(--shadow);padding:14px;position:relative;flex:0 0 auto}
.big-tile .n{font-size:.78rem;color:var(--muted)}.big-tile .s{font-size:3.8rem;font-weight:950;letter-spacing:-.08em;line-height:1;margin-top:12px}.big-tile:after{content:"";position:absolute;left:14px;right:14px;bottom:12px;height:5px;border-radius:8px;background:var(--accent,var(--green))}
.title-copy h1{font-size:clamp(3rem,6vw,5.8rem);letter-spacing:-.07em;line-height:.92;margin:4px 0 10px}.title-copy p{color:var(--muted);line-height:1.6;margin:0}
.element-visual{height:280px;background:var(--surface);border:1px solid var(--line);border-radius:30px;box-shadow:var(--shadow);position:relative;overflow:hidden}
.element-visual .grid{position:absolute;inset:0;opacity:.3;background-image:linear-gradient(rgba(15,107,87,.08) 1px,transparent 1px),linear-gradient(90deg,rgba(15,107,87,.08) 1px,transparent 1px);background-size:24px 24px}
.visual-atom{position:absolute;inset:24px}.visual-atom .core{position:absolute;left:50%;top:50%;width:54px;height:54px;transform:translate(-50%,-50%);border-radius:50%;background:var(--accent,var(--amber));box-shadow:0 0 0 16px color-mix(in srgb,var(--accent,var(--amber)) 16%,transparent)}
.visual-atom .ring{position:absolute;left:50%;top:50%;width:210px;height:88px;border:2px solid color-mix(in srgb,var(--accent,var(--green)) 55%,transparent);border-radius:50%;transform:translate(-50%,-50%) rotate(var(--r))}
.visual-atom .ring:after{content:"";position:absolute;width:13px;height:13px;border-radius:50%;background:var(--accent,var(--green));right:18px;top:10px}.visual-atom .r1{--r:0deg}.visual-atom .r2{--r:60deg}.visual-atom .r3{--r:-60deg}
.visual-label{position:absolute;left:20px;bottom:16px;font-weight:900;color:var(--green);font-size:1.05rem}

.info-grid{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:10px}.info-card{background:var(--surface);border:1px solid var(--line);border-radius:18px;padding:16px}.info-card span{display:block;color:var(--muted);font-size:.75rem;margin-bottom:5px}.info-card strong{font-size:1.1rem}
.content-grid{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:24px;margin-top:24px}.article-card,.side-card{background:var(--surface);border:1px solid var(--line);border-radius:24px;padding:24px;box-shadow:var(--shadow2)}
.article-card h2,.side-card h3{margin:0 0 12px;letter-spacing:-.03em}.article-card p,.side-card p{color:var(--muted);line-height:1.75;margin:0}
.neighbor-links{display:grid;gap:9px;margin-top:12px}.neighbor-links a{padding:11px 12px;border:1px solid var(--line);border-radius:14px;text-decoration:none;display:flex;justify-content:space-between}
.breadcrumbs{font-size:.8rem;color:var(--muted);display:flex;gap:7px;align-items:center;margin-top:14px}.breadcrumbs a{text-decoration:none}
body.dark{--bg:#0e1512;--surface:#17201c;--surface2:#1e2a25;--text:#f3f7f5;--muted:#a8b4ae;--line:#314139;--green:#78e0c4;--green2:#9af2db;--mint:#1d3b32;--amber:#f4bd63;--shadow:0 20px 55px rgba(0,0,0,.18);--shadow2:0 8px 24px rgba(0,0,0,.13);background:radial-gradient(circle at 93% 5%,rgba(120,224,196,.08),transparent 28%),linear-gradient(180deg,#111815,#0d1311)}
body.dark .pill,body.dark .theme-button,body.dark .language-menu{background:#17201c}
body.dark .element:hover{border-color:var(--green)}
@media(max-width:1050px){.hero{grid-template-columns:1fr}.hero-lab{display:none}.element-list{grid-template-columns:repeat(4,1fr)}.element-hero{grid-template-columns:1fr}.element-visual{height:230px}.info-grid{grid-template-columns:repeat(3,1fr)}}
@media(max-width:720px){.page{width:min(100% - 18px,720px)}.header-actions .pill{display:none}.hero{padding-top:38px}.hero h1{font-size:3.3rem}.table-toolbar{align-items:flex-start;flex-direction:column}.legend{display:none}
.pt-wrap{overflow:visible}.periodic-table{min-width:0;display:grid;grid-template-columns:repeat(4,1fr);grid-auto-rows:auto;gap:8px}.element{grid-column:auto!important;grid-row:auto!important;min-height:82px}.element .s{font-size:1.6rem}.element .nm{font-size:.67rem}.f-block{display:none}
.element-list{grid-template-columns:repeat(2,1fr)}.element-title{flex-direction:column}.big-tile{width:100px;height:112px}.big-tile .s{font-size:3.3rem}.title-copy h1{font-size:3rem}.info-grid{grid-template-columns:repeat(2,1fr)}.content-grid{grid-template-columns:1fr}.language-menu{max-width:200px;overflow-x:auto}.element-visual{height:210px}}
@media(max-width:430px){.periodic-table{grid-template-columns:repeat(3,1fr)}.info-grid{grid-template-columns:1fr 1fr}.element-list{grid-template-columns:1fr 1fr}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}

/* SIGNATURE HOME */
.signature-home{width:min(1530px,calc(100% - 24px));margin:auto;padding:16px 0 72px}
.sig-header{display:flex;align-items:center;justify-content:space-between;gap:14px;position:relative;z-index:30}
.sig-brand{display:flex;align-items:center;gap:12px;text-decoration:none}
.sig-brand-text strong{display:block;font-size:1.15rem;letter-spacing:-.03em}.sig-brand-text span{font-size:.66rem;letter-spacing:.14em;text-transform:uppercase;color:var(--green);font-weight:850}
.sig-nav{display:flex;align-items:center;gap:7px}.sig-nav>a{padding:9px 11px;border-radius:999px;text-decoration:none;font-size:.8rem;font-weight:800;color:var(--muted)}
.sig-nav>a:hover{background:var(--mint);color:var(--green)}.sig-langs{display:flex;border:1px solid var(--line);border-radius:999px;padding:4px;background:var(--surface)}
.sig-langs a{font-size:.67rem;font-weight:900;text-decoration:none;color:var(--muted);padding:5px 6px;border-radius:999px}.sig-langs a.active{background:var(--green);color:white}
.sig-theme{border:1px solid var(--line);background:var(--surface);width:38px;height:38px;border-radius:50%;color:var(--text)}
.sig-hero{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(300px,.62fr);gap:28px;align-items:center;padding:58px 0 30px}
.sig-kicker{display:flex;align-items:center;gap:9px;color:var(--green);font-size:.72rem;font-weight:900;letter-spacing:.13em;text-transform:uppercase}.sig-kicker:before{content:"";width:24px;border-top:2px solid var(--amber)}
.sig-hero h1{font-size:clamp(3.35rem,6.8vw,7.2rem);line-height:.86;letter-spacing:-.08em;margin:13px 0 20px;max-width:1000px}
.sig-hero h1 em{font-style:normal;color:var(--green)}.sig-hero p{font-size:1.08rem;line-height:1.7;color:var(--muted);max-width:760px}
.hero-actions{display:flex;gap:9px;flex-wrap:wrap;margin-top:22px}.hero-actions a{padding:11px 15px;border-radius:999px;text-decoration:none;font-weight:850;font-size:.84rem}.hero-actions .primary{background:var(--green);color:white}.hero-actions .secondary{border:1px solid var(--line);background:var(--surface)}
.hero-science{position:relative;height:270px;background:linear-gradient(145deg,var(--surface),color-mix(in srgb,var(--mint) 48%,var(--surface)));border:1px solid var(--line);border-radius:34px;box-shadow:var(--shadow);overflow:hidden}
.hero-science:before{content:"";position:absolute;inset:0;background-image:linear-gradient(rgba(15,107,87,.06) 1px,transparent 1px),linear-gradient(90deg,rgba(15,107,87,.06) 1px,transparent 1px);background-size:25px 25px}
.hero-flask-big{position:absolute;width:125px;height:150px;left:48px;top:55px;border:4px solid var(--green);border-radius:14px 14px 50px 50px;transform:rotate(-8deg);overflow:hidden}.hero-flask-big:before{content:"";position:absolute;width:42px;height:54px;left:37px;top:-43px;border:4px solid var(--green);background:var(--surface)}
.hero-flask-big .liquid{position:absolute;left:-10px;right:-10px;bottom:-5px;height:66px;background:linear-gradient(180deg,var(--amber2),var(--amber));transform:rotate(5deg)}.hero-flask-big i,.hero-flask-big b,.hero-flask-big em{position:absolute;border-radius:50%;background:var(--green)}.hero-flask-big i{width:8px;height:8px;left:28px;top:42px}.hero-flask-big b{width:6px;height:6px;right:24px;top:60px}.hero-flask-big em{width:4px;height:4px;left:60px;top:24px}
.hero-atom{position:absolute;right:24px;top:32px;width:160px;height:160px}.hero-atom .core{position:absolute;left:50%;top:50%;width:33px;height:33px;transform:translate(-50%,-50%);background:var(--green);border-radius:50%;box-shadow:0 0 0 11px color-mix(in srgb,var(--green) 14%,transparent)}.hero-atom .orbit{position:absolute;left:50%;top:50%;width:145px;height:61px;border:2px solid color-mix(in srgb,var(--green) 45%,transparent);border-radius:50%;transform:translate(-50%,-50%) rotate(var(--r))}.hero-atom .orbit:after{content:"";position:absolute;width:9px;height:9px;border-radius:50%;background:var(--amber);right:15px;top:6px}.hero-atom .o1{--r:0deg}.hero-atom .o2{--r:60deg}.hero-atom .o3{--r:-60deg}
.hero-mini-stat{position:absolute;right:26px;bottom:25px;text-align:right}.hero-mini-stat strong{font-size:2rem;letter-spacing:-.06em}.hero-mini-stat span{display:block;color:var(--muted);font-size:.72rem}
.table-stage{position:relative;margin-top:8px;background:color-mix(in srgb,var(--surface) 88%,transparent);border:1px solid var(--line);border-radius:30px;padding:16px;box-shadow:var(--shadow)}
.table-topbar{display:grid;grid-template-columns:1fr auto;gap:14px;align-items:center;margin-bottom:12px}.table-title-row{display:flex;gap:12px;align-items:center}.table-title-row h2{font-size:1.45rem;letter-spacing:-.04em;margin:0}.table-title-row span{font-size:.75rem;color:var(--muted)}
.sig-search{position:relative;width:min(360px,100%)}.sig-search:before{content:"⌕";position:absolute;left:14px;top:50%;transform:translateY(-50%);color:var(--muted)}.sig-search input{width:100%;border:1px solid var(--line);background:var(--bg);padding:11px 15px 11px 37px;border-radius:999px;color:var(--text);outline:none}.sig-search input:focus{border-color:var(--green);box-shadow:0 0 0 3px color-mix(in srgb,var(--green) 12%,transparent)}
.table-scroll{overflow-x:auto;padding:2px 2px 12px;scrollbar-width:thin;scroll-snap-type:x proximity}
.sig-table{min-width:1260px;display:grid;grid-template-columns:repeat(18,minmax(58px,1fr));grid-template-rows:repeat(7,82px);gap:6px;position:relative}
.sig-el{position:relative;text-decoration:none;color:var(--text);border:1px solid color-mix(in srgb,var(--accent) 36%,var(--line));border-radius:15px;background:linear-gradient(150deg,color-mix(in srgb,var(--accent) 12%,var(--surface)),var(--surface) 72%);padding:7px 7px 8px;box-shadow:0 5px 14px rgba(20,35,29,.045);transition:transform .16s ease,box-shadow .16s ease,border-color .16s ease;overflow:hidden}
.sig-el:hover,.sig-el.focused{z-index:15;transform:translateY(-4px) scale(1.055);border-color:var(--accent);box-shadow:0 13px 30px color-mix(in srgb,var(--accent) 20%,transparent)}
.sig-el:after{content:"";position:absolute;inset:auto 0 0;height:4px;background:var(--accent)}.sig-el .top{display:flex;justify-content:space-between;gap:4px;align-items:start}.sig-el .num{font-size:.58rem;color:var(--muted)}.sig-el .phase-dot{width:6px;height:6px;border-radius:50%;background:var(--accent);margin-top:2px}.sig-el .sym{font-size:1.5rem;font-weight:950;letter-spacing:-.055em;line-height:1;margin:7px 0 5px}.sig-el .name{font-size:.6rem;color:var(--muted);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.cat-nonmetal{--accent:#54aa7d}.cat-noble_gas{--accent:#6fa7cc}.cat-alkali_metal{--accent:#d68c3e}.cat-alkaline_earth_metal{--accent:#d4ae56}.cat-metalloid{--accent:#64a69a}.cat-halogen{--accent:#83ad59}.cat-transition_metal{--accent:#9d80ae}.cat-post_transition_metal{--accent:#7f98a0}.cat-lanthanide{--accent:#53aeb1}.cat-actinide{--accent:#c47b72}.cat-unknown{--accent:#9aa39e}
.table-center-card{position:absolute;left:calc((100% / 18) * 2 + 12px);top:6px;width:calc((100% / 18) * 10 - 18px);height:calc(82px * 3 + 12px);border:1px solid var(--line);border-radius:24px;background:radial-gradient(circle at 80% 10%,color-mix(in srgb,var(--green) 12%,transparent),transparent 34%),var(--surface);display:grid;grid-template-columns:1fr 190px;gap:12px;align-items:center;padding:22px 22px 20px;z-index:2;overflow:hidden}
.table-center-card h3{font-size:clamp(1.55rem,2.6vw,2.8rem);letter-spacing:-.055em;line-height:.96;margin:6px 0 9px}.table-center-card p{font-size:.78rem;color:var(--muted);line-height:1.55;margin:0;max-width:500px}
.center-symbol{height:160px;border-radius:24px;border:1px solid var(--line);background:linear-gradient(145deg,var(--mint),var(--surface));display:grid;place-items:center;position:relative}.center-symbol strong{font-size:5.2rem;letter-spacing:-.08em;color:var(--green)}.center-symbol span{position:absolute;top:13px;left:15px;font-size:.72rem;color:var(--muted)}
.center-meta{display:flex;gap:6px;flex-wrap:wrap;margin-top:11px}.center-meta span{border:1px solid var(--line);border-radius:999px;padding:5px 8px;font-size:.65rem;color:var(--muted)}
.mobile-hint{display:none;font-size:.72rem;color:var(--muted);margin:4px 2px 10px}.f-strip{display:grid;grid-template-columns:110px 1fr;gap:10px;align-items:start;margin-top:9px}.f-label{font-size:.71rem;color:var(--muted);font-weight:850;padding:11px 2px}.f-elements{display:grid;grid-template-columns:repeat(15,minmax(58px,1fr));gap:6px;min-width:1050px}.f-scroll{overflow-x:auto;scrollbar-width:thin}.f-elements .sig-el{min-height:74px}
.quick-panel{position:fixed;left:50%;bottom:14px;transform:translate(-50%,120%);width:min(520px,calc(100% - 18px));z-index:60;background:color-mix(in srgb,var(--surface) 96%,transparent);border:1px solid var(--line);border-radius:24px;box-shadow:0 25px 75px rgba(0,0,0,.22);padding:14px;transition:transform .2s ease;backdrop-filter:blur(12px)}.quick-panel.open{transform:translate(-50%,0)}.quick-inner{display:grid;grid-template-columns:76px 1fr auto;gap:13px;align-items:center}.quick-tile{height:76px;border-radius:18px;background:linear-gradient(145deg,color-mix(in srgb,var(--quick) 18%,var(--surface)),var(--surface));border:1px solid color-mix(in srgb,var(--quick) 40%,var(--line));display:grid;place-items:center;font-size:2.4rem;font-weight:950;color:var(--quick)}.quick-copy strong{display:block;font-size:1.1rem}.quick-copy span{font-size:.74rem;color:var(--muted);display:block;margin-top:3px}.quick-open{border:0;border-radius:999px;background:var(--green);color:#fff;padding:9px 11px;font-weight:850;text-decoration:none;font-size:.76rem}.quick-close{position:absolute;right:8px;top:7px;border:0;background:transparent;color:var(--muted);font-size:1rem}
.section-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:28px}.editorial-card{position:relative;overflow:hidden;background:var(--surface);border:1px solid var(--line);border-radius:28px;padding:28px;box-shadow:var(--shadow2)}.editorial-card h2{font-size:clamp(1.75rem,3.3vw,3rem);line-height:.98;letter-spacing:-.055em;margin:10px 0 14px}.editorial-card p{color:var(--muted);line-height:1.72;margin:0;max-width:700px}.story-year{font-size:5rem;line-height:.8;font-weight:950;letter-spacing:-.08em;color:color-mix(in srgb,var(--green) 15%,transparent);position:absolute;right:20px;top:22px}
.tool-preview{display:grid;grid-template-columns:repeat(2,1fr);gap:8px;margin-top:20px}.tool-preview a{text-decoration:none;padding:13px;border:1px solid var(--line);border-radius:16px;background:var(--bg);font-size:.78rem;font-weight:850;display:flex;justify-content:space-between}.tool-preview a b{color:var(--green)}
.footer-note{text-align:center;color:var(--muted);font-size:.72rem;margin-top:26px}
body.dark .hero-science,body.dark .table-stage,body.dark .editorial-card,body.dark .sig-langs,body.dark .sig-theme{background:#17201c}
body.dark .sig-el{background:linear-gradient(150deg,color-mix(in srgb,var(--accent) 12%,#17201c),#17201c 75%)}
body.dark .table-center-card{background:radial-gradient(circle at 80% 10%,color-mix(in srgb,var(--green) 10%,transparent),transparent 34%),#17201c}.dark .sig-search input,.dark .tool-preview a{background:#111815}
@media(max-width:980px){.sig-hero{grid-template-columns:1fr}.hero-science{display:none}.section-grid{grid-template-columns:1fr}.sig-nav>a{display:none}.table-center-card{grid-template-columns:1fr 130px}.center-symbol{height:130px}.center-symbol strong{font-size:4rem}}
@media(max-width:700px){
.signature-home{width:min(100% - 14px,700px);padding-top:10px}.sig-brand-text span{display:none}.sig-langs{max-width:180px;overflow-x:auto}.sig-theme{display:none}.sig-hero{padding:38px 4px 20px}.sig-hero h1{font-size:3.55rem}.sig-hero p{font-size:.96rem}
.table-stage{padding:10px;border-radius:22px}.table-topbar{grid-template-columns:1fr}.sig-search{width:100%;max-width:none}.table-title-row span{display:none}.mobile-hint{display:block}.table-scroll{margin-left:-10px;margin-right:-10px;padding-left:10px;padding-right:10px;scroll-padding-left:10px}
.sig-table{min-width:980px;grid-template-columns:repeat(18,49px);grid-template-rows:repeat(7,66px);gap:5px}.sig-el{border-radius:11px;padding:5px}.sig-el:hover{transform:none}.sig-el .sym{font-size:1.18rem;margin:5px 0 3px}.sig-el .name{font-size:.51rem}.sig-el .num{font-size:.5rem}
.table-center-card{left:108px;top:5px;width:535px;height:208px;border-radius:17px;padding:15px;grid-template-columns:1fr 105px}.table-center-card h3{font-size:1.65rem}.table-center-card p{font-size:.68rem}.center-symbol{height:100px;border-radius:16px}.center-symbol strong{font-size:3.2rem}.center-meta{display:none}
.f-strip{grid-template-columns:1fr}.f-label{padding:6px 0 0}.f-elements{grid-template-columns:repeat(15,49px);min-width:805px;gap:5px}.f-elements .sig-el{min-height:64px}
.section-grid{gap:10px;margin-top:17px}.editorial-card{padding:21px;border-radius:22px}.editorial-card h2{font-size:2rem}.story-year{font-size:3.5rem}.quick-inner{grid-template-columns:62px 1fr auto}.quick-tile{height:62px;font-size:2rem}.quick-panel{bottom:8px;border-radius:20px}}
@media(max-width:420px){.sig-hero h1{font-size:3rem}.sig-langs{max-width:150px}.sig-langs a{padding:5px;font-size:.62rem}.table-center-card{grid-template-columns:1fr}.center-symbol{display:none}.tool-preview{grid-template-columns:1fr 1fr}}
@media(prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important;scroll-behavior:auto!important}}


/* ===== Mendeleev V1 refined laboratory mark ===== */
.lab-logo{
  position:relative;
  width:48px;
  height:48px;
  flex:0 0 48px;
  border-radius:15px;
  background:
    radial-gradient(circle at 30% 25%,rgba(255,255,255,.75),transparent 28%),
    linear-gradient(145deg,color-mix(in srgb,var(--mint) 70%,var(--surface)),var(--surface));
  border:1px solid color-mix(in srgb,var(--green) 18%,var(--line));
  box-shadow:0 8px 22px rgba(20,40,32,.08);
  overflow:hidden;
}
.lab-logo .flask-neck{
  position:absolute;
  left:19px;
  top:8px;
  width:10px;
  height:12px;
  border:2px solid var(--green);
  border-bottom:0;
  border-radius:4px 4px 0 0;
}
.lab-logo .flask-body{
  position:absolute;
  left:12px;
  top:18px;
  width:24px;
  height:22px;
  border:2px solid var(--green);
  border-radius:6px 6px 12px 12px;
  overflow:hidden;
  transform:none;
  background:color-mix(in srgb,var(--surface) 82%,transparent);
}
.lab-logo .flask-body:before{
  content:"";
  position:absolute;
  left:3px;
  right:3px;
  top:8px;
  height:1px;
  background:color-mix(in srgb,var(--green) 22%,transparent);
}
.lab-logo .flask-liquid{
  position:absolute;
  left:-1px;
  right:-1px;
  bottom:-1px;
  height:9px;
  background:linear-gradient(180deg,var(--amber2),var(--amber));
  border-radius:50% 50% 8px 8px / 18% 18% 8px 8px;
}
.lab-logo .flask-body i,
.lab-logo .flask-body b{
  position:absolute;
  border-radius:50%;
  background:var(--green);
  opacity:.7;
}
.lab-logo .flask-body i{width:3px;height:3px;left:6px;top:5px}
.lab-logo .flask-body b{width:2px;height:2px;right:6px;top:7px}
.lab-logo:before,
.lab-logo:after{
  content:"";
  position:absolute;
  left:50%;
  top:50%;
  width:36px;
  height:15px;
  border:1px solid color-mix(in srgb,var(--green) 28%,transparent);
  border-radius:50%;
  transform:translate(-50%,-50%) rotate(34deg);
  pointer-events:none;
}
.lab-logo:after{transform:translate(-50%,-50%) rotate(-34deg)}



/* ===== Mendeleev historical CSS portrait ===== */
.mendeleev-story{
  display:grid;
  grid-template-columns:minmax(0,1fr) 220px;
  gap:26px;
  align-items:center;
}
.mendeleev-copy{position:relative;z-index:2}
.mendeleev-portrait{
  position:relative;
  height:270px;
  min-width:190px;
  align-self:end;
}
.mendeleev-portrait .periodic-ghost{
  position:absolute;
  inset:10px 0 auto 12px;
  display:grid;
  grid-template-columns:repeat(4,34px);
  gap:5px;
  transform:rotate(-4deg);
  opacity:.32;
}
.mendeleev-portrait .periodic-ghost i{
  display:block;
  width:34px;
  height:34px;
  border:1px solid color-mix(in srgb,var(--green) 32%,var(--line));
  border-radius:7px;
  background:color-mix(in srgb,var(--mint) 40%,transparent);
}
.mendeleev-portrait .periodic-ghost i:nth-child(2),
.mendeleev-portrait .periodic-ghost i:nth-child(5),
.mendeleev-portrait .periodic-ghost i:nth-child(8){transform:translateY(15px)}
.mendeleev-person{
  position:absolute;
  left:50%;
  bottom:0;
  width:170px;
  height:245px;
  transform:translateX(-50%);
}
.mendeleev-person .coat{
  position:absolute;
  left:16px;
  right:16px;
  bottom:0;
  height:98px;
  background:linear-gradient(145deg,#26352f,#17231e);
  border-radius:54px 54px 20px 20px;
  box-shadow:0 18px 34px rgba(20,35,29,.12);
}
.mendeleev-person .coat:before,
.mendeleev-person .coat:after{
  content:"";
  position:absolute;
  top:20px;
  width:64px;
  height:82px;
  background:linear-gradient(145deg,#30423a,#1b2924);
}
.mendeleev-person .coat:before{
  left:13px;
  clip-path:polygon(0 0,100% 48%,55% 100%,0 70%);
}
.mendeleev-person .coat:after{
  right:13px;
  clip-path:polygon(100% 0,0 48%,45% 100%,100% 70%);
}
.mendeleev-person .shirt{
  position:absolute;
  left:66px;
  bottom:70px;
  width:38px;
  height:44px;
  background:#f6f1e8;
  clip-path:polygon(0 0,100% 0,75% 100%,50% 76%,25% 100%);
  z-index:2;
}
.mendeleev-person .head{
  position:absolute;
  left:46px;
  top:44px;
  width:78px;
  height:92px;
  background:linear-gradient(160deg,#d7bfa6,#b99c83);
  border-radius:46% 46% 42% 42% / 42% 42% 58% 58%;
  z-index:4;
  box-shadow:inset -8px -6px 14px rgba(70,49,34,.08);
}
.mendeleev-person .head:before,
.mendeleev-person .head:after{
  content:"";
  position:absolute;
  top:45px;
  width:7px;
  height:4px;
  border-radius:50%;
  background:#344139;
}
.mendeleev-person .head:before{left:21px}
.mendeleev-person .head:after{right:21px}
.mendeleev-person .nose{
  position:absolute;
  left:50%;
  top:86px;
  width:8px;
  height:20px;
  border-right:2px solid rgba(71,51,39,.45);
  border-bottom:2px solid rgba(71,51,39,.32);
  border-radius:0 0 8px 0;
  transform:translateX(-50%);
  z-index:6;
}
.mendeleev-person .hair-left,
.mendeleev-person .hair-right{
  position:absolute;
  top:32px;
  width:63px;
  height:103px;
  background:
    repeating-linear-gradient(82deg,rgba(245,243,235,.96) 0 4px,rgba(180,178,168,.92) 4px 7px);
  border-radius:58% 32% 55% 45%;
  z-index:3;
  filter:drop-shadow(0 6px 4px rgba(30,40,35,.05));
}
.mendeleev-person .hair-left{left:19px;transform:rotate(9deg)}
.mendeleev-person .hair-right{right:19px;transform:scaleX(-1) rotate(9deg)}
.mendeleev-person .crown{
  position:absolute;
  left:48px;
  top:26px;
  width:74px;
  height:50px;
  border-radius:50% 50% 20% 20%;
  background:repeating-linear-gradient(96deg,#d9d8d0 0 4px,#bdbbb1 4px 7px);
  z-index:5;
  clip-path:polygon(0 65%,15% 25%,42% 0,63% 4%,86% 28%,100% 72%,85% 50%,65% 44%,43% 46%,23% 53%);
}
.mendeleev-person .beard{
  position:absolute;
  left:39px;
  top:107px;
  width:92px;
  height:108px;
  background:
    repeating-linear-gradient(83deg,#e4e1d7 0 4px,#bbb9b0 4px 7px);
  clip-path:polygon(8% 0,92% 0,98% 27%,86% 58%,68% 87%,51% 100%,30% 84%,12% 58%,2% 27%);
  border-radius:42% 42% 50% 50%;
  z-index:7;
  filter:drop-shadow(0 8px 6px rgba(30,40,35,.07));
}
.mendeleev-person .beard:before{
  content:"";
  position:absolute;
  left:25px;
  top:2px;
  width:43px;
  height:13px;
  border-top:5px solid #a7a49b;
  border-radius:50%;
}
.mendeleev-signature{
  position:absolute;
  right:5px;
  bottom:4px;
  font-family:Georgia,serif;
  font-style:italic;
  font-size:.7rem;
  color:var(--muted);
  transform:rotate(-5deg);
}
body.dark .mendeleev-person .coat{
  background:linear-gradient(145deg,#384a42,#1d2924);
}
body.dark .mendeleev-person .head{
  background:linear-gradient(160deg,#c5aa91,#9f826b);
}
@media(max-width:760px){
  .mendeleev-story{grid-template-columns:1fr 145px;gap:8px}
  .mendeleev-portrait{height:220px;min-width:130px;transform:scale(.85);transform-origin:right bottom}
  .mendeleev-portrait .periodic-ghost{display:none}
}
@media(max-width:520px){
  .mendeleev-story{display:block}
  .mendeleev-portrait{
    height:178px;
    width:135px;
    min-width:0;
    float:right;
    margin:-8px -10px 4px 10px;
    transform:scale(.72);
    transform-origin:right bottom;
  }
}


/* ===== V1.2 refined Mendeleev portrait ===== */
.mendeleev-signature{display:none!important}
.mendeleev-portrait{height:258px;min-width:194px}
.mendeleev-person{width:174px;height:238px}
.mendeleev-person .coat{
  left:18px;right:18px;height:94px;border-radius:58px 58px 18px 18px;
  background:linear-gradient(150deg,#31423b 0%,#1c2924 62%,#16221d 100%);
}
.mendeleev-person .head{
  left:47px;top:43px;width:80px;height:91px;
  background:linear-gradient(155deg,#dec5aa 0%,#c2a287 68%,#b49378 100%);
  border-radius:48% 48% 44% 44% / 44% 44% 56% 56%;
  box-shadow:inset -8px -5px 12px rgba(77,52,34,.08),inset 5px 3px 10px rgba(255,255,255,.16);
}
.mendeleev-person .head:before,
.mendeleev-person .head:after{top:43px;width:8px;height:4px;background:#39433d;box-shadow:0 -6px 0 -2px #66584b}
.mendeleev-person .head:before{left:21px;transform:rotate(-5deg)}
.mendeleev-person .head:after{right:21px;transform:rotate(5deg)}
.mendeleev-person .nose{left:50%;top:84px;width:7px;height:17px;border-right:2px solid rgba(79,55,40,.34);border-bottom:2px solid rgba(79,55,40,.26)}
.mendeleev-person .smile{
  position:absolute;left:73px;top:105px;width:28px;height:11px;
  border-bottom:3px solid #755747;border-radius:0 0 50% 50%;z-index:8;
}
.mendeleev-person .hair-left,
.mendeleev-person .hair-right{
  top:31px;width:64px;height:99px;
  background:
    radial-gradient(ellipse at 28% 22%,#eeeae0 0 14%,transparent 15%),
    radial-gradient(ellipse at 68% 34%,#d7d3c8 0 17%,transparent 18%),
    radial-gradient(ellipse at 42% 62%,#c4c0b6 0 20%,transparent 21%),
    linear-gradient(135deg,#e4e0d6 0%,#b8b4aa 100%);
  border-radius:60% 34% 58% 46%;
  filter:drop-shadow(0 5px 5px rgba(30,40,35,.055));
}
.mendeleev-person .hair-left{left:19px;transform:rotate(8deg)}
.mendeleev-person .hair-right{right:19px;transform:scaleX(-1) rotate(8deg)}
.mendeleev-person .crown{
  left:49px;top:27px;width:76px;height:47px;
  background:linear-gradient(145deg,#e5e1d7,#bdb9af);
  clip-path:polygon(2% 70%,11% 33%,30% 9%,51% 2%,72% 12%,91% 38%,99% 72%,82% 54%,63% 48%,42% 48%,21% 55%);
  border-radius:50%;
}
.mendeleev-person .beard{
  left:38px;top:106px;width:96px;height:108px;
  background:
    radial-gradient(ellipse at 35% 22%,rgba(255,255,255,.32) 0 13%,transparent 14%),
    radial-gradient(ellipse at 65% 34%,rgba(255,255,255,.18) 0 16%,transparent 17%),
    linear-gradient(145deg,#e5e1d7 0%,#c5c0b5 55%,#aaa69d 100%);
  clip-path:polygon(7% 0,93% 0,99% 27%,88% 58%,70% 87%,51% 100%,31% 86%,12% 59%,1% 27%);
  border-radius:44% 44% 51% 51%;
  filter:drop-shadow(0 8px 6px rgba(30,40,35,.07));
}
.mendeleev-person .beard:before{
  content:"";position:absolute;left:23px;top:4px;width:50px;height:13px;
  border-top:5px solid #9d998f;border-radius:50%;
}


/* ===== V1.2 editorial discovery cards ===== */
.discovery-grid{
  display:grid;
  grid-template-columns:repeat(4,minmax(0,1fr));
  gap:12px;
  margin-top:22px;
}
.discovery-card{
  position:relative;
  min-height:215px;
  overflow:hidden;
  border:1px solid var(--line);
  border-radius:24px;
  padding:20px;
  text-decoration:none;
  color:var(--text);
  background:var(--surface);
  box-shadow:var(--shadow2);
  transition:transform .16s ease,border-color .16s ease;
}
.discovery-card:hover{transform:translateY(-3px);border-color:var(--green)}
.discovery-card .eyebrow{margin-bottom:8px}
.discovery-card h3{font-size:1.18rem;letter-spacing:-.035em;line-height:1.08;margin:0 0 9px;max-width:210px}
.discovery-card p{font-size:.8rem;line-height:1.55;color:var(--muted);margin:0;max-width:230px}
.discovery-card .examples{
  display:flex;flex-wrap:wrap;gap:5px;margin-top:14px;max-width:230px
}
.discovery-card .examples span{
  font-size:.64rem;font-weight:800;padding:5px 7px;border-radius:999px;
  background:color-mix(in srgb,var(--accent) 11%,var(--surface));
  border:1px solid color-mix(in srgb,var(--accent) 24%,var(--line));
}
.discovery-card .arrow{
  position:absolute;right:15px;bottom:13px;width:32px;height:32px;border-radius:50%;
  display:grid;place-items:center;background:color-mix(in srgb,var(--accent) 12%,var(--surface));
  color:var(--accent);font-weight:900
}
.discovery-card .mini-visual{position:absolute;right:8px;top:8px;width:78px;height:78px;opacity:.9}
.discovery-card.daily{--accent:#3e9e72}
.discovery-card.objects{--accent:#d79432}
.discovery-card.families{--accent:#8463a7}
.discovery-card.converters{--accent:#4d80c7}
.mini-daily:before,.mini-daily:after{content:"";position:absolute}
.mini-daily:before{width:46px;height:60px;border:3px solid var(--accent);border-radius:10px;left:10px;top:8px;transform:rotate(-11deg)}
.mini-daily:after{width:28px;height:22px;border-radius:50% 50% 45% 45%;background:color-mix(in srgb,var(--accent) 25%,transparent);right:0;bottom:7px;border:3px solid var(--accent)}
.mini-objects:before{content:"";position:absolute;left:14px;top:6px;width:48px;height:65px;border:3px solid var(--accent);border-radius:9px;transform:rotate(8deg);box-shadow:inset 0 0 0 10px color-mix(in srgb,var(--accent) 9%,transparent)}
.mini-families:before{content:"";position:absolute;left:23px;top:14px;width:34px;height:34px;background:color-mix(in srgb,var(--accent) 30%,transparent);border:3px solid var(--accent);transform:rotate(45deg);box-shadow:15px 15px 0 -5px color-mix(in srgb,var(--accent) 20%,transparent),-12px 17px 0 -6px color-mix(in srgb,var(--accent) 18%,transparent)}
.mini-converters:before{content:"";position:absolute;left:32px;top:4px;width:14px;height:58px;border:3px solid var(--accent);border-radius:10px}
.mini-converters:after{content:"";position:absolute;left:25px;bottom:4px;width:28px;height:28px;border-radius:50%;background:color-mix(in srgb,var(--accent) 20%,transparent);border:3px solid var(--accent)}
.discovery-intro{margin-top:34px}
.discovery-intro h2{font-size:clamp(1.6rem,3vw,2.5rem);letter-spacing:-.045em;margin:0 0 8px}
.discovery-intro p{color:var(--muted);max-width:760px;line-height:1.65;margin:0}
@media(max-width:920px){.discovery-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:560px){
 .discovery-grid{grid-template-columns:1fr}
 .discovery-card{min-height:185px}
 .discovery-card h3,.discovery-card p{max-width:78%}
}


/* ===== V2 production editorial ===== */
.mendeleev-portrait .periodic-ghost{display:grid!important}
.mendeleev-signature{display:none!important}
.v2-editorial{margin-top:28px}
.v2-story{background:var(--surface);border:1px solid var(--line);border-radius:26px;padding:24px;box-shadow:var(--shadow2)}
.v2-story h2{font-size:clamp(1.7rem,3vw,2.7rem);letter-spacing:-.045em;margin:0 0 12px}
.v2-story p{font-size:.98rem;line-height:1.76;color:var(--muted);margin:0}
.v2-factline{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:16px}
.v2-factline div{border:1px solid var(--line);background:var(--bg);border-radius:15px;padding:12px}
.v2-factline span{display:block;color:var(--muted);font-size:.7rem;margin-bottom:4px}.v2-factline strong{font-size:.95rem}
.v2-note{margin-top:14px;padding:14px 16px;border-radius:16px;background:color-mix(in srgb,var(--mint) 55%,var(--surface));border:1px solid color-mix(in srgb,var(--green) 18%,var(--line));font-size:.82rem;line-height:1.6;color:var(--muted)}
@media(max-width:700px){.v2-story{padding:19px;border-radius:21px}.v2-factline{grid-template-columns:1fr 1fr}}


/* ===== V2 launch: About / Fl + Mt ===== */
.about-hero{padding:56px 0 24px;max-width:1020px}
.about-hero h1{font-size:clamp(3.2rem,7vw,6.8rem);line-height:.9;letter-spacing:-.075em;margin:10px 0 18px}
.about-hero p{font-size:1.05rem;line-height:1.75;color:var(--muted);max-width:820px}
.creators-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:22px 0}
.creator-card{background:var(--surface);border:1px solid var(--line);border-radius:28px;padding:26px;box-shadow:var(--shadow2)}
.creator-head{display:flex;align-items:center;gap:18px;margin-bottom:18px}
.chem-signature{
 width:92px;height:102px;flex:0 0 92px;position:relative;
 border:1px solid color-mix(in srgb,var(--sig) 45%,var(--line));
 border-radius:20px;padding:10px;
 background:linear-gradient(145deg,color-mix(in srgb,var(--sig) 15%,var(--surface)),var(--surface));
 box-shadow:0 12px 30px color-mix(in srgb,var(--sig) 13%,transparent)
}
.chem-signature .atomic{position:absolute;left:11px;top:9px;font-size:.68rem;color:var(--muted);font-weight:800}
.chem-signature .symbol{display:grid;place-items:center;height:64px;font-size:3.1rem;font-weight:950;letter-spacing:-.08em;color:var(--sig)}
.chem-signature .name{position:absolute;left:10px;right:10px;bottom:9px;font-size:.63rem;color:var(--muted);text-align:center;font-weight:800}
.chem-signature.fl{--sig:#48a47c}.chem-signature.mt{--sig:#8a74ae}
.creator-title h2{margin:0 0 4px;font-size:1.8rem;letter-spacing:-.045em}
.creator-title p{margin:0;color:var(--muted);font-size:.84rem}
.creator-card>p{color:var(--muted);line-height:1.78;margin:0}
.about-section{background:var(--surface);border:1px solid var(--line);border-radius:28px;padding:28px;margin-top:16px;box-shadow:var(--shadow2)}
.about-section h2{font-size:clamp(1.7rem,3vw,2.6rem);letter-spacing:-.045em;margin:0 0 12px}
.about-section p{color:var(--muted);line-height:1.78;margin:0 0 12px}
.about-section p:last-child{margin-bottom:0}
.about-values{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:18px}
.about-value{border:1px solid var(--line);border-radius:18px;padding:16px;background:var(--bg)}
.about-value strong{display:block;margin-bottom:5px}.about-value span{font-size:.78rem;color:var(--muted);line-height:1.5}
.about-quote{padding:45px 18px;text-align:center}
.about-quote strong{font-size:clamp(1.8rem,4vw,3.4rem);letter-spacing:-.05em;line-height:1.05;display:block}
.about-quote em{display:block;color:var(--green);font-size:1.05rem;margin-top:9px;font-style:normal}
.about-quote small{display:block;color:var(--muted);margin-top:14px;font-weight:800}
.legal-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin-top:16px}
.legal-item{border-top:1px solid var(--line);padding-top:14px}
.legal-item h3{font-size:.95rem;margin:0 0 6px}.legal-item p{font-size:.82rem;line-height:1.65}
.footer-about-link{color:var(--muted);text-decoration:none;font-weight:800;margin-left:8px}
.footer-about-link:hover{color:var(--green)}
@media(max-width:760px){
 .creators-grid{grid-template-columns:1fr}.about-values{grid-template-columns:1fr}.legal-grid{grid-template-columns:1fr}
 .creator-card{padding:20px;border-radius:22px}.about-section{padding:21px;border-radius:22px}
 .chem-signature{width:78px;height:88px;flex-basis:78px}.chem-signature .symbol{height:54px;font-size:2.6rem}
}

/* ===== V2.1 portrait correction ===== */
.mendeleev-portrait .periodic-ghost{display:grid!important}
.mendeleev-signature{display:none!important}
.mendeleev-person .hair-left,
.mendeleev-person .hair-right{
  background:linear-gradient(145deg,#e8e4da 0%,#cbc7bd 48%,#aaa69d 100%)!important;
}
.mendeleev-person .beard{
  background:linear-gradient(150deg,#e8e4da 0%,#cbc6bb 58%,#aaa69d 100%)!important;
}
.footer-about-link{font-weight:400!important}

/* ===== V2.2 unified converter chrome ===== */
.tools-unified-header{margin-bottom:8px}
.tools-unified-header .brand{min-width:max-content}
.tools-unified-header .language-menu a.active{background:var(--green);color:#fff}
.tools-site-footer{
  margin-top:38px;padding:22px 2px 4px;border-top:1px solid var(--line);
  display:flex;align-items:center;justify-content:space-between;gap:18px;color:var(--muted)
}
.tools-footer-brand strong{display:block;color:var(--text);font-size:.94rem}
.tools-footer-brand span{display:block;font-size:.72rem;margin-top:3px}
.tools-site-footer nav{display:flex;flex-wrap:wrap;justify-content:flex-end;gap:14px}
.tools-site-footer nav a{color:var(--muted);text-decoration:none;font-size:.75rem;font-weight:400}
.tools-site-footer nav a:hover{color:var(--green)}
@media(max-width:820px){
 .tools-unified-header .tools-elements-pill{display:none}
 .tools-site-footer{align-items:flex-start;flex-direction:column}
 .tools-site-footer nav{justify-content:flex-start}
}
@media(max-width:620px){
 .tools-unified-header .tools-home-pill{display:none}
 .tools-unified-header .header-actions{gap:5px}
 .tools-unified-header .language-menu{max-width:190px;overflow-x:auto}
 .tools-site-footer{margin-top:26px;padding-top:18px}
}

.tools-unified-header .lab-logo{width:48px!important;height:48px!important}
.tools-unified-header .brand-name{font-weight:900!important;letter-spacing:-.03em!important;font-size:1.18rem!important}
.tools-unified-header .eyebrow{font-size:.7rem!important;letter-spacing:.14em!important;color:var(--green)!important}

/* ===== V2.2 production converter shared chrome ===== */
.tools-unified-header .brand{display:flex;align-items:center;gap:13px;text-decoration:none;color:inherit}
.tools-unified-header .pill{
  padding:9px 12px;text-decoration:none;font-size:.82rem;font-weight:750;
  border:1px solid var(--line);background:rgba(255,253,248,.9);border-radius:999px;color:var(--text)
}
.tools-unified-header .theme-button{
  width:40px;height:40px;cursor:pointer;border:1px solid var(--line);
  background:rgba(255,253,248,.9);border-radius:999px;color:var(--text)
}
body.dark .tools-unified-header .pill,
body.dark .tools-unified-header .theme-button{background:#17201c}

/* ===== public footer cleanup ===== */
.footer-note,.footer-note a,.tools-site-footer-minimal,.tools-site-footer-minimal a{font-weight:400!important}
.tools-site-footer-minimal{
 display:flex!important;flex-direction:row!important;align-items:center!important;justify-content:flex-start!important;
 gap:7px!important;color:var(--muted)!important;font-size:.75rem!important
}
.tools-site-footer-minimal a{color:var(--muted);text-decoration:none}
.tools-site-footer-minimal a:hover{color:var(--green)}

/* ===== Editorial element experience ===== */
.element-experience{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(280px,.75fr);gap:16px;margin-top:20px}
.element-story-card,.element-context-card,.source-card{background:var(--surface);border:1px solid var(--line);border-radius:26px;padding:24px;box-shadow:var(--shadow2)}
.element-story-card h2,.element-context-card h2{font-size:clamp(1.5rem,2.5vw,2.2rem);letter-spacing:-.045em;margin:7px 0 11px}.element-story-card p,.element-context-card p{color:var(--muted);line-height:1.78;margin:0 0 12px}
.element-use-chips{display:flex;flex-wrap:wrap;gap:7px;margin-top:14px}.element-use-chips span{padding:7px 10px;border-radius:999px;background:var(--bg);border:1px solid var(--line);font-size:.72rem;font-weight:750}
.element-memory{margin-top:14px;padding:15px 17px;border-left:3px solid var(--green);border-radius:0 16px 16px 0;background:color-mix(in srgb,var(--mint) 48%,var(--surface));line-height:1.6;color:var(--text)}
.atomic-weight-card{display:flex;align-items:baseline;justify-content:space-between;gap:12px;margin-top:13px;padding:12px 14px;border-radius:15px;background:var(--bg);border:1px solid var(--line)}.atomic-weight-card span{font-size:.7rem;color:var(--muted)}.atomic-weight-card strong{font-size:.98rem}
.element-scene{--scene:#4f9c7b;position:relative;min-height:245px;border:1px solid color-mix(in srgb,var(--scene) 32%,var(--line));border-radius:24px;overflow:hidden;background:radial-gradient(circle at 78% 20%,color-mix(in srgb,var(--scene) 16%,transparent),transparent 32%),linear-gradient(150deg,color-mix(in srgb,var(--scene) 9%,var(--surface)),var(--surface));margin-bottom:16px}
.element-scene .scene-symbol{position:absolute;left:18px;top:15px;font-size:4.8rem;font-weight:950;letter-spacing:-.09em;color:color-mix(in srgb,var(--scene) 86%,var(--text))}.element-scene .scene-number{position:absolute;left:21px;top:88px;color:var(--muted);font-size:.72rem;font-weight:850}.element-scene .scene-orbit{position:absolute;right:22px;top:35px;width:115px;height:55px;border:2px solid color-mix(in srgb,var(--scene) 36%,transparent);border-radius:50%;transform:rotate(28deg)}.element-scene .scene-orbit:before,.element-scene .scene-orbit:after{content:"";position:absolute;border-radius:50%;background:var(--scene)}.element-scene .scene-orbit:before{width:9px;height:9px;right:13px;top:5px}.element-scene .scene-orbit:after{width:6px;height:6px;left:17px;bottom:5px}
.element-scene .object{position:absolute;left:50%;bottom:23px;transform:translateX(-20%);width:130px;height:105px}
.scene-battery .object{width:116px;height:62px;border:4px solid var(--scene);border-radius:14px}.scene-battery .object:after{content:"";position:absolute;right:-13px;top:17px;width:10px;height:27px;background:var(--scene);border-radius:0 5px 5px 0}.scene-battery .object:before{content:"+";position:absolute;left:15px;top:7px;font-size:32px;font-weight:900;color:var(--scene)}
.scene-chip .object{width:100px;height:82px;border:4px solid var(--scene);border-radius:14px;background:repeating-linear-gradient(90deg,transparent 0 13px,color-mix(in srgb,var(--scene) 13%,transparent) 13px 15px)}.scene-chip .object:before,.scene-chip .object:after{content:"";position:absolute;left:-18px;right:-18px;height:3px;top:18px;background:repeating-linear-gradient(90deg,var(--scene) 0 8px,transparent 8px 17px);box-shadow:0 22px 0 0 var(--scene),0 44px 0 0 var(--scene)}
.scene-cable .object{height:28px;width:140px;border:7px solid #2d3430;border-radius:20px;transform:translateX(-22%) rotate(-10deg)}.scene-cable .object:after{content:"";position:absolute;inset:3px 8px;background:repeating-linear-gradient(90deg,#b76a31 0 6px,#e0a265 6px 10px);border-radius:8px}
.scene-glass .object{width:100px;height:95px;border:4px solid var(--scene);border-radius:10px 10px 28px 28px;transform:translateX(-15%) rotate(7deg);background:linear-gradient(180deg,transparent 45%,color-mix(in srgb,var(--scene) 20%,transparent) 46%)}
.scene-carbon .object{width:88px;height:88px;background:linear-gradient(135deg,color-mix(in srgb,var(--scene) 22%,transparent),transparent);border:4px solid var(--scene);transform:translateX(-10%) rotate(45deg);border-radius:12px}.scene-carbon .object:after{content:"";position:absolute;inset:18px;border:3px solid var(--scene);border-radius:50%}
.scene-oxygen .object,.scene-air .object,.scene-gas .object,.scene-toxicgas .object{width:120px;height:80px}.scene-oxygen .object:before,.scene-air .object:before,.scene-gas .object:before,.scene-toxicgas .object:before{content:"";position:absolute;width:54px;height:54px;border-radius:50%;border:4px solid var(--scene);left:4px;top:12px;box-shadow:58px 0 0 -4px var(--surface),58px 0 0 0 var(--scene)}
.scene-cosmos .object{width:112px;height:112px;border-radius:50%;background:radial-gradient(circle at 38% 38%,#fff7c9 0 8%,#f2be52 9% 27%,#d57f34 45%,transparent 47%);filter:drop-shadow(0 0 20px rgba(221,154,60,.25))}.scene-cosmos .object:after{content:"";position:absolute;width:7px;height:7px;border-radius:50%;background:var(--scene);right:-10px;top:13px;box-shadow:-130px 25px 0 -1px var(--scene),-85px -37px 0 -2px var(--scene)}
.scene-light .object,.scene-lamp .object{width:72px;height:104px;border:4px solid var(--scene);border-radius:50% 50% 20px 20px}.scene-light .object:after,.scene-lamp .object:after{content:"";position:absolute;left:19px;right:19px;bottom:-18px;height:18px;border:4px solid var(--scene);border-top:0;border-radius:0 0 7px 7px}
.scene-salt .object{width:95px;height:95px;border:4px solid var(--scene);transform:translateX(-15%) rotate(30deg);box-shadow:inset 20px 20px 0 color-mix(in srgb,var(--scene) 10%,transparent)}
.scene-bone .object{width:125px;height:34px;border-radius:25px;background:var(--scene);transform:translateX(-20%) rotate(-14deg)}.scene-bone .object:before,.scene-bone .object:after{content:"";position:absolute;width:42px;height:42px;border-radius:50%;background:var(--scene);top:-4px}.scene-bone .object:before{left:-16px;box-shadow:0 25px 0 var(--scene)}.scene-bone .object:after{right:-16px;box-shadow:0 25px 0 var(--scene)}
.scene-steel .object,.scene-aerospace .object,.scene-lightmetal .object{width:135px;height:70px;clip-path:polygon(0 35%,70% 0,100% 18%,68% 35%,100% 54%,70% 66%,0 100%,35% 54%);background:var(--scene)}
.scene-coin .object,.scene-gold .object{width:92px;height:92px;border-radius:50%;border:6px double var(--scene);box-shadow:14px 12px 0 color-mix(in srgb,var(--scene) 18%,transparent)}
.scene-galvanize .object,.scene-alloy .object,.scene-hardmetal .object,.scene-heat .object,.scene-jet .object{width:125px;height:75px;border:5px solid var(--scene);border-radius:10px;transform:translateX(-18%) rotate(-8deg);background:repeating-linear-gradient(135deg,color-mix(in srgb,var(--scene) 18%,transparent) 0 9px,transparent 9px 18px)}
.scene-medical .object,.scene-medicine .object{width:92px;height:92px;border-radius:50%;border:4px solid var(--scene)}.scene-medical .object:before,.scene-medicine .object:before{content:"+";position:absolute;inset:5px;display:grid;place-items:center;font-size:58px;font-weight:900;color:var(--scene)}
.scene-clock .object{width:94px;height:94px;border-radius:50%;border:5px solid var(--scene)}.scene-clock .object:before{content:"";position:absolute;width:4px;height:34px;background:var(--scene);left:45px;top:14px;transform-origin:bottom;transform:rotate(20deg)}.scene-clock .object:after{content:"";position:absolute;width:30px;height:4px;background:var(--scene);left:45px;top:45px;transform-origin:left;transform:rotate(25deg)}
.scene-firework .object{width:5px;height:90px;background:var(--scene)}.scene-firework .object:before{content:"✦";position:absolute;font-size:72px;color:var(--scene);left:-34px;top:-48px}
.scene-reactor .object,.scene-radioactive .object,.scene-neutron .object,.scene-smoke .object,.scene-research .object{width:100px;height:100px;border-radius:50%;border:4px solid var(--scene)}.scene-reactor .object:before,.scene-radioactive .object:before,.scene-neutron .object:before,.scene-smoke .object:before,.scene-research .object:before{content:"";position:absolute;inset:31px;border-radius:50%;background:var(--scene);box-shadow:0 -35px 0 -8px var(--scene),30px 18px 0 -8px var(--scene),-30px 18px 0 -8px var(--scene)}
.scene-catalyst .object{width:110px;height:78px;border-radius:18px;background:radial-gradient(circle,var(--scene) 0 4px,transparent 5px);background-size:22px 22px;border:4px solid var(--scene)}
.scene-screen .object{width:120px;height:82px;border:5px solid var(--scene);border-radius:12px;background:linear-gradient(145deg,color-mix(in srgb,var(--scene) 20%,transparent),transparent)}.scene-screen .object:after{content:"";position:absolute;left:35px;right:35px;bottom:-16px;height:12px;border-top:4px solid var(--scene)}
.scene-laser .object,.scene-fiber .object,.scene-optics .object{width:120px;height:70px}.scene-laser .object:before,.scene-fiber .object:before,.scene-optics .object:before{content:"";position:absolute;left:0;top:34px;width:120px;height:4px;background:var(--scene);box-shadow:80px -12px 0 -1px color-mix(in srgb,var(--scene) 65%,transparent),80px 12px 0 -1px color-mix(in srgb,var(--scene) 65%,transparent)}
.scene-superconduct .object,.scene-magnet .object{width:120px;height:85px;border:15px solid var(--scene);border-top:0;border-radius:0 0 48px 48px}.scene-superconduct .object:before,.scene-magnet .object:before{content:"";position:absolute;left:-15px;top:-4px;width:38px;height:26px;background:#d55}.scene-superconduct .object:after,.scene-magnet .object:after{content:"";position:absolute;right:-15px;top:-4px;width:38px;height:26px;background:#5b7fc8}
.scene-capacitor .object{width:54px;height:90px;border:5px solid var(--scene);border-radius:10px}.scene-capacitor .object:before,.scene-capacitor .object:after{content:"";position:absolute;width:4px;height:42px;background:var(--scene);bottom:-40px}.scene-capacitor .object:before{left:11px}.scene-capacitor .object:after{right:11px}
.scene-liquidmetal .object,.scene-liquid .object{width:100px;height:55px;border-radius:50% 50% 45% 45%;background:linear-gradient(145deg,#eef1ee,var(--scene));box-shadow:inset -18px -8px 22px rgba(0,0,0,.12)}
.scene-shield .object{width:100px;height:115px;clip-path:polygon(50% 0,95% 18%,86% 72%,50% 100%,14% 72%,5% 18%);background:var(--scene)}
.scene-sulfur .object{width:100px;height:82px;clip-path:polygon(10% 55%,25% 12%,58% 0,92% 25%,85% 75%,42% 100%);background:#e4c735;border:4px solid color-mix(in srgb,#b09616 70%,var(--line))}
.scene-tin .object{width:95px;height:110px;border:4px solid var(--scene);border-radius:12px 12px 18px 18px;background:linear-gradient(90deg,transparent 0 15%,color-mix(in srgb,var(--scene) 15%,transparent) 16% 23%,transparent 24%)}
.scene-solar .object{width:125px;height:80px;border:4px solid var(--scene);transform:translateX(-18%) rotate(-10deg);background:repeating-linear-gradient(90deg,transparent 0 20px,var(--scene) 21px 23px),repeating-linear-gradient(0deg,color-mix(in srgb,var(--scene) 17%,transparent) 0 17px,var(--scene) 18px 20px)}
.scene-toxicity .object,.scene-toxic .object{width:95px;height:95px;border:5px solid var(--scene);transform:translateX(-10%) rotate(45deg)}.scene-toxic .object:before{content:"!";position:absolute;inset:0;display:grid;place-items:center;font-size:58px;font-weight:950;color:var(--scene);transform:rotate(-45deg)}
.source-card{margin-top:16px}.source-card h3{margin:0 0 10px;font-size:1rem}.source-links{display:flex;flex-wrap:wrap;gap:8px}.source-links a{font-size:.72rem;text-decoration:none;color:var(--muted);padding:7px 9px;border:1px solid var(--line);border-radius:999px;background:var(--bg)}.source-links a:hover{color:var(--green);border-color:var(--green)}
@media(max-width:800px){.element-experience{grid-template-columns:1fr}.element-scene{min-height:210px}.element-story-card,.element-context-card{padding:20px;border-radius:21px}}

/* V4.2.3 — explicit mobile discovery navigation */
.mobile-discover{display:none}
@media(max-width:760px){
 body{padding-bottom:68px}
 .mobile-discover{position:fixed;z-index:80;display:flex;left:8px;right:8px;bottom:8px;gap:4px;padding:7px;background:rgba(255,255,255,.96);backdrop-filter:blur(14px);border:1px solid var(--line);border-radius:18px;box-shadow:0 10px 32px rgba(20,35,30,.14);overflow-x:auto}
 .mobile-discover a{flex:0 0 auto;padding:9px 11px;border-radius:12px;text-decoration:none;color:var(--ink);font-size:.78rem;font-weight:700;white-space:nowrap}
 .mobile-discover a:active{background:var(--soft)}
}

/* V4.2.4 — stable mobile navigation */
.mobile-discover{display:none}
@media(max-width:760px){
 body{padding-bottom:76px}
 .mobile-discover{
  position:fixed;z-index:999;left:8px;right:8px;bottom:8px;
  display:flex;align-items:center;gap:5px;padding:7px;
  overflow-x:auto;-webkit-overflow-scrolling:touch;
  border:1px solid var(--line);border-radius:18px;
  background:rgba(255,255,255,.96);backdrop-filter:blur(14px);
  box-shadow:0 12px 30px rgba(20,35,30,.16)
 }
 .mobile-discover a{
  display:block;flex:0 0 auto;padding:9px 11px;border-radius:11px;
  color:var(--ink);text-decoration:none;font-size:.78rem;font-weight:750;
  white-space:nowrap
 }
 .mobile-discover a:hover,.mobile-discover a:focus{background:var(--soft)}
}

/* V4.2.4 home balance */
.editorial-full{grid-column:1/-1;width:100%;box-sizing:border-box}
.tool-examples-expanded{display:flex;flex-wrap:wrap;gap:7px}
.tool-examples-expanded span{white-space:nowrap}

.material-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:18px 0}
.material-part{padding:18px;border:1px solid var(--line);border-radius:18px;background:var(--surface)}
.material-part h3{margin:0 0 8px}.material-part p,.object-note{line-height:1.68;color:var(--muted)}
.object-note{margin-top:18px;padding-top:18px;border-top:1px solid var(--line)}
@media(max-width:760px){.material-grid{grid-template-columns:1fr}}

.home-editorial-v2.editorial-full{grid-column:1/-1;width:100%;max-width:none}.editorial-more{margin-top:18px;padding:22px 24px;border:1px solid var(--line);border-radius:22px;background:var(--surface)}.editorial-more p{line-height:1.7}

.404-language-links{display:flex;flex-wrap:wrap;gap:8px;margin-top:24px}
.404-language-links a{padding:9px 12px;border:1px solid var(--line);border-radius:999px;text-decoration:none;color:var(--ink);background:var(--surface)}

/* V4.3.1 explore pages */
.explore-hero{padding:46px 0 22px;max-width:920px}
.explore-kicker{font-size:.72rem;letter-spacing:.13em;text-transform:uppercase;font-weight:800;color:var(--green);margin-bottom:10px}
.explore-hero h1{font-size:clamp(2.6rem,6vw,5.4rem);line-height:.94;letter-spacing:-.06em;margin:0 0 14px}
.explore-hero p{max-width:780px;color:var(--muted);font-size:1.06rem;line-height:1.7}
.explore-visual{position:relative;height:240px;margin:4px 0 20px;border:1px solid var(--line);border-radius:26px;background:linear-gradient(145deg,var(--surface),color-mix(in srgb,var(--green) 5%,var(--surface)));overflow:hidden;box-shadow:var(--shadow2)}
.explore-visual .caption{position:absolute;left:18px;bottom:14px;font-size:.7rem;color:var(--muted);letter-spacing:.06em;text-transform:uppercase}
.visual-pencil:before{content:"";position:absolute;left:18%;top:46%;width:58%;height:28px;border-radius:6px;background:#d7ad55;transform:rotate(-10deg);box-shadow:inset 0 -7px rgba(0,0,0,.08)}
.visual-pencil:after{content:"";position:absolute;left:72%;top:36%;border-left:68px solid #d7b58a;border-top:15px solid transparent;border-bottom:15px solid transparent;transform:rotate(-10deg)}
.visual-pencil .lead{position:absolute;left:80%;top:44%;width:31px;height:7px;background:#3e4442;transform:rotate(-10deg);border-radius:0 5px 5px 0}
.visual-pencil .eraser{position:absolute;left:15.5%;top:49%;width:40px;height:28px;background:#c9878d;transform:rotate(-10deg);border-radius:7px 0 0 7px}
.visual-pencil .paper{position:absolute;left:15%;right:15%;bottom:20%;height:2px;background:var(--line);transform:rotate(-2deg)}
@media(max-width:760px){.explore-hero{padding-top:30px}.explore-visual{height:190px}.explore-hero h1{font-size:2.55rem}}

/* V4.3.2 — balance scales */
.scale-story{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:22px 0}
.scale-scene{position:relative;min-height:310px;border:1px solid var(--line);border-radius:26px;background:linear-gradient(145deg,var(--surface),color-mix(in srgb,var(--green) 5%,var(--surface)));overflow:hidden;box-shadow:var(--shadow2)}
.scale-scene .scene-label{position:absolute;left:16px;top:14px;font-size:.7rem;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:800}
.old-scale .stand{position:absolute;left:50%;bottom:42px;width:14px;height:145px;background:#697570;transform:translateX(-50%);border-radius:8px}
.old-scale .base{position:absolute;left:35%;right:35%;bottom:26px;height:18px;border-radius:50%;background:#697570}
.old-scale .beam{position:absolute;left:17%;right:17%;top:108px;height:8px;background:#5e6a66;border-radius:8px;transform-origin:center;animation:balanceBeam 4s ease-in-out infinite}
.old-scale .beam:after{content:"";position:absolute;left:50%;top:-13px;width:8px;height:34px;background:#5e6a66;transform:translateX(-50%)}
.old-scale .pan{position:absolute;top:150px;width:112px;height:18px;border-bottom:4px solid #7a8581;border-radius:0 0 55px 55px}
.old-scale .pan:before,.old-scale .pan:after{content:"";position:absolute;top:-55px;width:2px;height:58px;background:#8a9591}
.old-scale .pan:before{left:18px;transform:rotate(18deg)} .old-scale .pan:after{right:18px;transform:rotate(-18deg)}
.old-scale .left{left:13%}.old-scale .right{right:13%}
.old-scale .object{position:absolute;left:20%;top:127px;width:72px;height:45px;border-radius:12px;background:#8aa99f}
.old-scale .weights{position:absolute;right:17%;top:118px;display:flex;align-items:flex-end;gap:5px}
.old-scale .weight{display:grid;place-items:center;width:38px;height:48px;border-radius:8px 8px 4px 4px;background:#9a8570;color:white;font-size:.6rem;font-weight:800}
.old-scale .w2{height:40px}.old-scale .w3{height:34px}
@keyframes balanceBeam{0%,20%{transform:rotate(-4deg)}55%,100%{transform:rotate(0)}}
.digital-scale .platform{position:absolute;left:24%;right:24%;top:68px;height:26px;border-radius:10px;background:#909b97}
.digital-scale .body{position:absolute;left:29%;right:29%;top:92px;height:125px;border-radius:14px 14px 28px 28px;background:#d9e0dd;border:1px solid #b6c1bd}
.digital-scale .loadcell{position:absolute;left:35%;right:35%;top:120px;height:18px;border:4px solid #687570;border-radius:8px;animation:flexCell 3.2s ease-in-out infinite}
.digital-scale .gauge{position:absolute;left:44%;right:44%;top:123px;height:12px;background:repeating-linear-gradient(90deg,#4f8a76 0 5px,transparent 5px 8px)}
.digital-scale .display{position:absolute;left:38%;right:38%;top:165px;padding:8px 4px;border-radius:7px;background:#27322f;color:#bce9cb;font:700 1rem ui-monospace,monospace;text-align:center}
.digital-scale .signal{position:absolute;left:50%;top:145px;font-size:24px;color:#4f8a76;animation:pulseSignal 2s ease-in-out infinite}
@keyframes flexCell{50%{transform:scaleY(.78)}} @keyframes pulseSignal{50%{opacity:.3;transform:translateY(6px)}}
.scale-copy-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:18px}.scale-copy-grid section{padding:22px;border:1px solid var(--line);border-radius:22px;background:var(--surface)}
.scale-tools{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px}.scale-tools a{padding:9px 12px;border:1px solid var(--line);border-radius:999px;text-decoration:none;color:var(--ink);font-weight:700}
.scale-memory{margin-top:18px;padding:18px 20px;border-left:4px solid var(--green);background:var(--surface);border-radius:14px}
@media(max-width:760px){.scale-story,.scale-copy-grid{grid-template-columns:1fr}.scale-scene{min-height:275px}}

/* V4.3.3 everyday object animations */
.object-lab{position:relative;height:250px;margin:18px 0 22px;border:1px solid var(--line);border-radius:26px;overflow:hidden;background:linear-gradient(145deg,var(--surface),color-mix(in srgb,var(--green) 6%,var(--surface)));box-shadow:var(--shadow2)}
.object-lab .lab-caption{position:absolute;left:16px;bottom:12px;font-size:.7rem;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:800}
.visual-thermometer .tube{position:absolute;left:50%;top:35px;width:28px;height:150px;border:4px solid #7a8782;border-radius:16px;transform:translateX(-50%);background:#f6f8f7}
.visual-thermometer .liquid{position:absolute;left:calc(50% - 7px);bottom:66px;width:14px;height:54px;border-radius:8px;background:#c75f55;animation:thermoRise 4s ease-in-out infinite}
.visual-thermometer .bulb{position:absolute;left:50%;bottom:42px;width:48px;height:48px;transform:translateX(-50%);border-radius:50%;background:#c75f55;border:4px solid #7a8782}
.visual-thermometer .marks{position:absolute;left:54%;top:52px;height:118px;width:38px;background:repeating-linear-gradient(to bottom,#7e8a86 0 2px,transparent 2px 16px)}
@keyframes thermoRise{50%{height:112px}}
.visual-pressure .pot{position:absolute;left:31%;right:31%;bottom:44px;height:112px;border-radius:12px 12px 42px 42px;background:#9aa4a1}
.visual-pressure .lid{position:absolute;left:27%;right:27%;bottom:155px;height:18px;border-radius:14px;background:#737e7a}
.visual-pressure .valve{position:absolute;left:50%;bottom:171px;width:20px;height:30px;transform:translateX(-50%);background:#5f6b67;border-radius:6px}
.visual-pressure .steam{position:absolute;left:50%;bottom:195px;font-size:35px;color:#94b9ad;animation:steamPulse 2s ease-in-out infinite}
.visual-pressure .gauge-ring{position:absolute;right:18%;top:46px;width:62px;height:62px;border:5px solid #7d8b86;border-radius:50%}
.visual-pressure .needle{position:absolute;right:23%;top:77px;width:28px;height:3px;background:#b55e51;transform-origin:right center;animation:gaugeNeedle 3s ease-in-out infinite}
@keyframes gaugeNeedle{50%{transform:rotate(-55deg)}} @keyframes steamPulse{50%{transform:translateY(-10px);opacity:.35}}
.visual-fridge .box{position:absolute;left:35%;right:35%;top:26px;bottom:34px;border:5px solid #74817d;border-radius:18px;background:#eef3f1}
.visual-fridge .split{position:absolute;left:35%;right:35%;top:102px;height:4px;background:#74817d}
.visual-fridge .cold{position:absolute;left:41%;top:56px;font-size:42px;animation:coldPulse 2.5s ease-in-out infinite}
.visual-fridge .coil{position:absolute;right:20%;top:55px;width:52px;height:118px;background:repeating-linear-gradient(to bottom,#9b5f50 0 4px,transparent 4px 15px)}
.visual-fridge .heat{position:absolute;right:10%;top:84px;font-size:32px;animation:heatOut 2.8s ease-in-out infinite}
@keyframes coldPulse{50%{transform:scale(1.15)}} @keyframes heatOut{50%{transform:translateX(12px);opacity:.35}}
.object-explain-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.object-explain-grid section{padding:20px;border:1px solid var(--line);border-radius:20px;background:var(--surface)}
.object-explain-grid p{line-height:1.7;color:var(--muted)}
.object-links{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px}
.object-links a{padding:9px 12px;border:1px solid var(--line);border-radius:999px;text-decoration:none;color:var(--ink);font-weight:700}
@media(max-width:760px){.object-explain-grid{grid-template-columns:1fr}.object-lab{height:220px}}

/* V4.3.4 — clearer mechanical balance */
.old-scale .beam{left:14%;right:14%}
.old-scale .pan.left{left:10%}.old-scale .pan.right{right:10%}
.old-scale .object{left:calc(10% + 20px);top:116px;width:72px;height:54px;display:grid;place-items:center;color:#fff;font-size:.66rem;font-weight:800;text-align:center}
.old-scale .weights{right:calc(10% + 8px);top:116px;width:96px;justify-content:center;gap:3px}
.old-scale .weight{width:30px;font-size:.52rem}
.balance-equation{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:14px;margin:18px 0;padding:18px;border:1px solid var(--line);border-radius:20px;background:var(--surface)}
.balance-equation .eq-side{text-align:center}.balance-equation .eq-big{display:block;font-size:clamp(1.4rem,4vw,2.4rem);font-weight:850;letter-spacing:-.04em}.balance-equation .eq-note{display:block;margin-top:5px;color:var(--muted);font-size:.82rem}.balance-equation .eq-sign{font-size:2rem;color:var(--green);font-weight:900}
.beam-callout{margin:14px 0;padding:14px 16px;border-radius:16px;background:color-mix(in srgb,var(--green) 7%,var(--surface));line-height:1.65}
@media(max-width:600px){.balance-equation{grid-template-columns:1fr}.balance-equation .eq-sign{transform:rotate(90deg)}.old-scale .weights{right:calc(10% + 3px)}}

/* V4.3.4 — object mechanism diagrams */
.mech-diagram{position:relative;height:235px;margin:18px 0;border:1px solid var(--line);border-radius:25px;background:linear-gradient(145deg,var(--surface),color-mix(in srgb,var(--green) 5%,var(--surface)));overflow:hidden}
.mech-core{position:absolute;inset:55px 18% 55px;border:4px solid #7c8984;border-radius:20px;display:grid;place-items:center;font-weight:850;font-size:1.1rem;text-align:center;padding:15px}
.mech-arrow{position:absolute;top:50%;font-size:2rem;color:var(--green);font-weight:900;animation:mechPulse 2s ease-in-out infinite}.mech-arrow.a{left:7%}.mech-arrow.b{right:7%}
.mech-in,.mech-out{position:absolute;top:28px;font-size:.72rem;color:var(--muted);font-weight:800;text-transform:uppercase;letter-spacing:.06em}.mech-in{left:7%}.mech-out{right:7%}
@keyframes mechPulse{50%{transform:translateX(8px);opacity:.35}}

/* V4.4.0 homepage final statement — intentionally full-width */
.home-editorial-v2.editorial-full{width:100%;max-width:none;box-sizing:border-box;text-align:center;padding:36px clamp(24px,5vw,76px)}
.home-editorial-v2.editorial-full .eyebrow{text-align:center}
.home-editorial-v2.editorial-full p{max-width:1080px;margin:0 auto!important;text-align:center;font-size:1rem!important;line-height:1.8!important}
@media(max-width:760px){.home-editorial-v2.editorial-full{padding:26px 20px}.home-editorial-v2.editorial-full p{text-align:left}}

/* V4.4.1 — definitive homepage closing statement */
.home-editorial-v2.editorial-card.editorial-full{
  display:block!important; width:100%!important; max-width:none!important;
  margin:28px 0 0!important; box-sizing:border-box!important;
  padding:38px clamp(24px,6vw,92px)!important; text-align:center!important;
}
.home-editorial-v2.editorial-card.editorial-full .eyebrow{display:block;text-align:center!important;margin:0 auto 12px!important}
.home-editorial-v2.editorial-card.editorial-full p{
  display:block!important; width:100%!important; max-width:1120px!important;
  margin:0 auto!important; text-align:center!important; line-height:1.82!important;
}
@media(max-width:700px){
 .home-editorial-v2.editorial-card.editorial-full{padding:26px 20px!important}
 .home-editorial-v2.editorial-card.editorial-full p{text-align:left!important}
}

/* V4.4.1 — landing pages: no empty giant title bubble */
.explore-visual.is-landing-label{display:none!important}
.explore-hero{margin-bottom:18px}

/* V4.5.0 mobile navigation — persistent bottom dock */
@media(max-width:760px){
  .sig-header{position:relative!important;top:auto!important}
  .mobile-discover{
    position:fixed!important;left:8px!important;right:8px!important;bottom:8px!important;
    z-index:1200!important;display:grid!important;grid-auto-flow:column!important;
    grid-auto-columns:minmax(68px,1fr)!important;gap:4px!important;
    overflow-x:auto!important;padding:6px!important;
    border:1px solid var(--line)!important;border-radius:18px!important;
    background:color-mix(in srgb,var(--surface) 96%,transparent)!important;
    backdrop-filter:blur(14px)!important;box-shadow:0 12px 32px rgba(20,35,30,.18)!important
  }
  .mobile-discover a{
    display:grid!important;place-items:center!important;text-align:center!important;
    min-height:42px!important;padding:6px 8px!important;border-radius:12px!important;
    font-size:.70rem!important;line-height:1.05!important;font-weight:800!important;
    white-space:normal!important
  }
  body{padding-bottom:82px!important}
}

/* V4.5.0 compare tools */
.compare-shell{max-width:980px;margin:0 auto}
.compare-card{padding:24px;border:1px solid var(--line);border-radius:26px;background:var(--surface);box-shadow:var(--shadow2)}
.compare-inputs{display:grid;grid-template-columns:1fr 1fr minmax(130px,.65fr);gap:12px;align-items:end}
.compare-inputs label{display:grid;gap:7px;font-size:.76rem;font-weight:800;color:var(--muted)}
.compare-inputs input,.compare-inputs select{width:100%;box-sizing:border-box;padding:13px 14px;border:1px solid var(--line);border-radius:14px;background:var(--bg);color:var(--ink);font:inherit}
.compare-results{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-top:18px}
.compare-stat{padding:16px;border:1px solid var(--line);border-radius:18px;background:color-mix(in srgb,var(--green) 4%,var(--surface))}
.compare-stat span{display:block;font-size:.7rem;color:var(--muted);text-transform:uppercase;letter-spacing:.06em;font-weight:800}
.compare-stat strong{display:block;margin-top:7px;font-size:1.08rem}
.compare-bars{display:grid;gap:10px;margin-top:20px}.compare-bar-row{display:grid;grid-template-columns:34px 1fr;gap:8px;align-items:center}
.compare-bar-track{height:16px;border-radius:999px;background:var(--soft);overflow:hidden}.compare-bar-fill{height:100%;min-width:2px;border-radius:999px;background:var(--green);transition:width .18s ease}
.temp-conversions{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:18px}.temp-conversions div{padding:13px;border:1px solid var(--line);border-radius:15px}.temp-conversions strong,.temp-conversions span{display:block}.temp-conversions span{margin-top:4px;color:var(--muted)}
.compare-explain{margin-top:22px;display:grid;grid-template-columns:1fr 1fr;gap:14px}.compare-explain section{padding:20px;border:1px solid var(--line);border-radius:20px;background:var(--surface)}.compare-explain p{line-height:1.7;color:var(--muted)}
@media(max-width:720px){.compare-inputs{grid-template-columns:1fr}.compare-results{grid-template-columns:1fr 1fr}.compare-explain{grid-template-columns:1fr}.temp-conversions{grid-template-columns:1fr}}

/* V4.6 — original element visual, no external image dependency */
.element-orbit-visual{position:relative;height:220px;margin:22px 0;border:1px solid var(--line);border-radius:26px;overflow:hidden;background:radial-gradient(circle at 50% 50%,color-mix(in srgb,var(--green) 9%,var(--surface)),var(--surface) 62%)}
.element-orbit-visual .nucleus{position:absolute;left:50%;top:50%;width:72px;height:72px;transform:translate(-50%,-50%);border-radius:50%;display:grid;place-items:center;background:var(--green);color:#fff;font-size:1.7rem;font-weight:900;box-shadow:0 10px 35px rgba(20,70,55,.2)}
.element-orbit-visual .orbit{position:absolute;left:50%;top:50%;border:1px solid color-mix(in srgb,var(--green) 35%,var(--line));border-radius:50%;transform:translate(-50%,-50%) rotate(var(--r))}
.element-orbit-visual .o1{width:155px;height:58px;--r:18deg}.element-orbit-visual .o2{width:155px;height:58px;--r:78deg}.element-orbit-visual .o3{width:155px;height:58px;--r:138deg}
.element-orbit-visual .dot{position:absolute;width:10px;height:10px;border-radius:50%;background:var(--amber);left:calc(50% + var(--x));top:calc(50% + var(--y));box-shadow:0 0 0 4px color-mix(in srgb,var(--amber) 14%,transparent)}
.element-orbit-visual .visual-note{position:absolute;left:16px;bottom:13px;color:var(--muted);font-size:.7rem;letter-spacing:.05em}

/* V4.7 — comparison tools: visual difference first */
.compare-visual{margin-top:18px;padding:18px;border:1px solid var(--line);border-radius:20px;background:linear-gradient(145deg,var(--surface),color-mix(in srgb,var(--green) 5%,var(--surface)))}
.compare-visual-row{display:grid;grid-template-columns:28px 1fr 84px;gap:10px;align-items:center;margin:11px 0}
.compare-visual-row>strong{font-size:.8rem}.compare-visual-value{text-align:right;font-size:.8rem;font-weight:850}
.compare-visual-track{position:relative;height:22px;border-radius:999px;background:repeating-linear-gradient(90deg,var(--soft) 0 1px,transparent 1px 10%),var(--soft);overflow:hidden}
.compare-visual-fill{height:100%;min-width:3px;border-radius:999px;background:linear-gradient(90deg,var(--green),color-mix(in srgb,var(--green) 55%,var(--amber)));transition:width .2s ease}
.compare-delta{display:flex;justify-content:center;align-items:center;gap:8px;margin-top:12px;font-size:.78rem;color:var(--muted)}
.compare-delta strong{font-size:1.12rem;color:var(--ink)}
.temp-scale{position:relative;height:64px;margin-top:20px;border-radius:18px;background:linear-gradient(90deg,#c8e8f2,#edf1d7 50%,#f4c5aa);border:1px solid var(--line)}
.temp-marker{position:absolute;top:9px;width:4px;height:45px;border-radius:4px;background:var(--ink);transition:left .2s ease}
.temp-marker:after{content:attr(data-label);position:absolute;top:-4px;left:50%;transform:translate(-50%,-100%);font-size:.7rem;font-weight:850;white-space:nowrap}
.temp-marker.a{background:var(--green)}.temp-marker.b{background:var(--amber)}
.compare-presets{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.compare-presets button{border:1px solid var(--line);background:var(--surface);color:var(--ink);border-radius:999px;padding:8px 11px;font:inherit;font-size:.74rem;font-weight:800}
.compare-presets button:hover{background:var(--soft)}

/* V4.7 measurement comparison */
.example-callout-v47{margin:18px 0;padding:18px 20px;border:1px solid var(--line);border-radius:20px;background:color-mix(in srgb,var(--amber) 8%,var(--surface))}
.example-callout-v47 p{margin:.5rem 0 0;line-height:1.65;color:var(--ink)}
.compare-bar-track{position:relative}
.compare-bar-track:after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,transparent 24%,color-mix(in srgb,var(--ink) 8%,transparent) 25%,transparent 26%,transparent 49%,color-mix(in srgb,var(--ink) 8%,transparent) 50%,transparent 51%,transparent 74%,color-mix(in srgb,var(--ink) 8%,transparent) 75%,transparent 76%);pointer-events:none}
.compare-theme-section{margin:28px 0}.compare-theme-section .theme-grid{margin-top:14px}

/* V4.8 relation tools */
.relation-shell{max-width:980px;margin:0 auto}.relation-card{padding:24px;border:1px solid var(--line);border-radius:26px;background:var(--surface);box-shadow:var(--shadow2)}
.relation-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.relation-field{padding:16px;border:1px solid var(--line);border-radius:18px;background:color-mix(in srgb,var(--green) 3%,var(--surface))}
.relation-field label{display:block;font-weight:850;margin-bottom:8px}.relation-field .input-row{display:grid;grid-template-columns:1fr minmax(82px,.55fr);gap:8px}.relation-field input,.relation-field select{width:100%;box-sizing:border-box;padding:12px;border:1px solid var(--line);border-radius:12px;background:var(--bg);color:var(--ink);font:inherit}
.formula-visual{display:grid;grid-template-columns:1fr auto 1fr auto 1fr;align-items:center;gap:12px;margin:20px 0;padding:18px;border-radius:20px;background:color-mix(in srgb,var(--green) 6%,var(--surface));text-align:center}.formula-visual strong{font-size:1.05rem}.formula-visual b{font-size:1.5rem;color:var(--green)}
.relation-result{margin-top:18px;padding:18px 20px;border-left:4px solid var(--green);border-radius:14px;background:var(--surface)}.relation-result strong{display:block;font-size:1.4rem}.relation-result span{display:block;margin-top:5px;color:var(--muted)}
.relation-examples{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:20px}.relation-examples section{padding:20px;border:1px solid var(--line);border-radius:20px;background:var(--surface)}.relation-examples p{line-height:1.7;color:var(--muted)}
@media(max-width:720px){.relation-grid{grid-template-columns:1fr}.formula-visual{grid-template-columns:1fr}.formula-visual b{transform:rotate(90deg)}.relation-examples{grid-template-columns:1fr}}

/* V4.9 object stories */
.object-story-shell{max-width:1000px;margin:0 auto}.object-mechanism{display:grid;grid-template-columns:1fr auto 1fr auto 1fr;gap:12px;align-items:center;margin:20px 0 26px;padding:22px;border:1px solid var(--line);border-radius:24px;background:color-mix(in srgb,var(--amber) 5%,var(--surface));text-align:center}.mechanism-node{min-height:86px;display:grid;place-items:center;padding:10px;border-radius:18px;background:var(--surface);border:1px solid var(--line)}.object-mechanism>span{font-size:1.5rem;color:var(--amber)}.object-story-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.object-story-section{padding:22px;border:1px solid var(--line);border-radius:22px;background:var(--surface)}.object-story-section h2{margin-top:0;font-size:1.15rem}.object-story-section p{line-height:1.75;color:var(--muted)}@media(max-width:760px){.object-story-grid{grid-template-columns:1fr}.object-mechanism{grid-template-columns:1fr}.object-mechanism>span{transform:rotate(90deg)}}
\n\n/* V6.40 — scalable language selector + science article layout */
.language-selector{position:relative;z-index:80}
.language-selector summary{list-style:none;cursor:pointer;border:1px solid var(--line);border-radius:999px;padding:9px 12px;background:var(--surface);font-size:.74rem;font-weight:850;white-space:nowrap}
.language-selector summary::-webkit-details-marker{display:none}
.language-panel{position:absolute;right:0;top:calc(100% + 8px);width:min(390px,88vw);max-height:62vh;overflow:auto;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:5px;padding:10px;border:1px solid var(--line);border-radius:18px;background:var(--surface);box-shadow:var(--shadow2)}
.language-panel a{display:flex;align-items:center;justify-content:space-between;gap:8px;padding:9px 10px;border-radius:11px;text-decoration:none;color:var(--ink);font-size:.78rem}
.language-panel a:hover,.language-panel a.active{background:var(--soft)}
.language-panel small{color:var(--muted);font-weight:800;text-transform:uppercase}
.science-article-shell{max-width:1080px;margin:0 auto}
.science-article-grid{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:24px;align-items:start;margin:22px 0 42px}
.science-article{padding:clamp(22px,4vw,42px);border:1px solid var(--line);border-radius:28px;background:var(--surface);box-shadow:var(--shadow2)}
.science-article h2{margin:1.8em 0 .55em;font-size:clamp(1.25rem,2vw,1.6rem)}
.science-article h2:first-child{margin-top:0}.science-article p,.science-article li{line-height:1.78}.science-article p{color:var(--muted)}
.science-article ul{padding-left:1.25rem}.science-article strong{color:var(--ink)}
.science-toc{position:sticky;top:18px;padding:18px;border:1px solid var(--line);border-radius:22px;background:color-mix(in srgb,var(--green) 3%,var(--surface))}
.science-toc strong{display:block;margin-bottom:10px}.science-toc a{display:block;padding:7px 0;text-decoration:none;color:var(--muted);font-size:.84rem}.science-toc a:hover{color:var(--ink)}
.science-note{margin:20px 0;padding:17px 18px;border-left:4px solid var(--green);border-radius:14px;background:color-mix(in srgb,var(--green) 6%,var(--surface));line-height:1.7}
.science-source-list{font-size:.86rem}.science-source-list a{color:var(--green);font-weight:800}
.science-topic-nav{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0 20px}.science-topic-nav a{padding:8px 11px;border:1px solid var(--line);border-radius:999px;text-decoration:none;font-size:.76rem;font-weight:800;color:var(--ink);background:var(--surface)}
@media(max-width:780px){.language-panel{grid-template-columns:1fr}.science-article-grid{grid-template-columns:1fr}.science-toc{position:relative;top:auto;order:-1}.site-header{gap:10px;align-items:flex-start}.header-actions{flex-wrap:wrap;justify-content:flex-end}}

/* V6.41.0 V3 navigation + editorial QA */
.language-selector .language-panel{max-height:min(68vh,34rem);overflow:auto;min-width:18rem;grid-template-columns:repeat(2,minmax(0,1fr));}
.language-selector .language-panel::before{content:none!important;display:none!important;}
.science-related{margin-top:2rem;padding-top:1.25rem;border-top:1px solid var(--border,#d8dde5);}
.science-related h2{margin-top:0}
.science-related-links{display:flex;flex-wrap:wrap;gap:.55rem}
.science-related-links a{display:inline-flex;padding:.55rem .8rem;border:1px solid var(--border,#d8dde5);border-radius:999px;text-decoration:none}
.site-footer-v3{margin:3rem auto 1.5rem;padding:1.25rem 0;border-top:1px solid var(--border,#d8dde5);font-size:.92rem;opacity:.82}
.site-footer-v3 nav{display:flex;flex-wrap:wrap;gap:1rem}
@media(max-width:680px){.language-selector .language-panel{grid-template-columns:1fr;min-width:min(88vw,20rem)}}

/* V6.42.0 multilingual menu + content quality */
.language-group-label{grid-column:1/-1;padding:.55rem .55rem .2rem;font-size:.72rem;text-transform:uppercase;letter-spacing:.08em;font-weight:800;opacity:.58}
.language-search{grid-column:1/-1;width:100%;box-sizing:border-box;padding:.65rem .75rem;border:1px solid var(--border,#d8dde5);border-radius:.65rem;background:transparent;color:inherit}
.v3-depth{margin:1.5rem 0;padding:1.2rem 1.3rem;border:1px solid var(--border,#d8dde5);border-radius:1rem;background:var(--card,#fff)}
.v3-depth h2{margin-top:0}
.source-list{margin:.8rem 0 0;padding-left:1.15rem}
.pilot-badge{display:inline-block;padding:.22rem .5rem;border:1px solid currentColor;border-radius:999px;font-size:.72rem;opacity:.75}

/* V6.43.0 element pilot */
.data-grid{display:grid;grid-template-columns:minmax(12rem,1fr) 2fr;gap:.45rem 1rem;margin:0}
.data-grid dt{font-weight:700;opacity:.72} .data-grid dd{margin:0}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(11rem,1fr));gap:.8rem;margin:1.2rem 0 2rem}
.grid .card{display:flex;flex-direction:column;gap:.2rem;padding:1rem;border:1px solid var(--border,#d8dde5);border-radius:1rem;text-decoration:none}
.grid .card strong{font-size:1.55rem} .grid .card small{opacity:.68}

/* V6.44.0 nomenclature */
.international-name{margin:.3rem 0 1rem;opacity:.68}

/* V6.47.0 human science editorial */
.science-human{margin:1.8rem 0;padding:1.35rem 1.45rem;border-left:4px solid currentColor;border-radius:.25rem 1rem 1rem .25rem;background:var(--card,#fff)}
.science-human .eyebrow{margin-bottom:.35rem}
.science-human h2{margin:.15rem 0 .7rem}
.science-human p{max-width:72ch;line-height:1.68}
.curiosity-note{font-style:italic;opacity:.78}

/* V6.57 accessible conceptual atom visual */
.atom-visual{position:relative;width:min(280px,72vw);aspect-ratio:1;margin:1.5rem auto;display:grid;place-items:center}
.atom-ring{position:absolute;border:1px solid currentColor;border-radius:50%;opacity:.28}
.atom-ring-1{inset:40%}.atom-ring-2{inset:32%}.atom-ring-3{inset:24%}.atom-ring-4{inset:16%}.atom-ring-5{inset:10%}.atom-ring-6{inset:5%}.atom-ring-7{inset:0}
.atom-core{position:relative;z-index:2;display:grid;place-items:center;width:4.4rem;height:4.4rem;border:2px solid currentColor;border-radius:50%;background:var(--surface,#fff)}
.atom-core small{font-size:.68rem;font-weight:500}
@media(prefers-reduced-motion:reduce){.atom-visual *{animation:none!important}}

/* V6.58 simple conceptual sketches */
.concept-sketch{display:flex;align-items:center;justify-content:center;gap:.55rem;min-height:7rem;margin:1rem auto;max-width:30rem}
.concept-sketch span{display:block;width:2.1rem;height:2.1rem;border:2px solid currentColor;border-radius:50%;opacity:.72}
.concept-sketch span:nth-child(2){width:1.25rem;height:1.25rem}.concept-sketch span:nth-child(3){border-style:dashed}
.concept-sketch b{font-size:1.8rem;font-weight:500}

/* V6.59 guided science */
.journey-line{display:grid;gap:1rem}.journey-step{display:grid;grid-template-columns:2.4rem 1fr;gap:.8rem;align-items:start}.journey-step>b{display:grid;place-items:center;width:2.2rem;height:2.2rem;border:1px solid currentColor;border-radius:50%}.journey-step p{margin:.25rem 0}


/* V6.61 emergency unified UI */
html{color-scheme:light dark}
body{margin:0;background:var(--bg,#f7f8fa);color:var(--ink,#18211f);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.55}
.page,.signature-home{width:min(1180px,calc(100% - 28px));margin:0 auto}
.site-header,.sig-header{display:flex;align-items:center;justify-content:space-between;gap:18px;padding:18px 0;position:relative;z-index:100}
.site-header a,.sig-header a{text-decoration:none;color:inherit}
.sig-nav,.header-actions{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.language-selector{position:relative;z-index:1000}
.language-selector summary{display:flex;align-items:center;gap:7px;list-style:none;cursor:pointer;border:1px solid var(--line,#d7dfdc);border-radius:999px;padding:9px 12px;background:var(--surface,#fff);font-size:.78rem;font-weight:800;white-space:nowrap}
.language-selector summary::-webkit-details-marker{display:none}
.language-selector summary small{opacity:.6}.language-selector summary b{font-size:1rem;margin-left:2px}
.language-panel{position:absolute;right:0;top:calc(100% + 10px);width:min(620px,92vw);max-height:min(72vh,620px);overflow:auto;padding:14px;background:var(--surface,#fff);border:1px solid var(--line,#d7dfdc);border-radius:18px;box-shadow:0 18px 60px rgba(0,0,0,.18);z-index:1001}
.language-panel-head{position:sticky;top:-14px;z-index:2;background:var(--surface,#fff);padding:4px 0 12px;display:grid;grid-template-columns:auto 1fr;gap:12px;align-items:center}
.language-search{width:100%;box-sizing:border-box;padding:10px 12px;border:1px solid var(--line,#d7dfdc);border-radius:10px;background:var(--surface,#fff);color:inherit}
.language-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:6px}
.language-grid a{display:flex;align-items:center;justify-content:space-between;gap:8px;padding:10px;border-radius:10px;color:inherit;text-decoration:none;border:1px solid transparent}
.language-grid a:hover,.language-grid a.active{background:var(--soft,#edf5f2);border-color:var(--line,#d7dfdc)}
.language-grid small{opacity:.58;font-weight:800}
.hero,.sig-hero{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(220px,.65fr);gap:32px;align-items:center;padding:42px 0}
.hero h1,.sig-hero h1{font-size:clamp(2.2rem,5vw,5.3rem);line-height:.98;letter-spacing:-.045em;margin:.15em 0 .3em}
.hero p,.sig-hero p{max-width:68ch;font-size:1.06rem}
.v3-depth,.science-human,.card,.table-stage{background:var(--surface,#fff);border:1px solid var(--line,#d7dfdc);border-radius:18px;padding:20px;margin:18px 0}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));gap:12px}.grid .card{margin:0;text-decoration:none;color:inherit}
.breadcrumbs{display:flex;gap:8px;flex-wrap:wrap;font-size:.84rem;opacity:.72;margin:10px 0}
.data-grid{display:grid;grid-template-columns:minmax(150px,1fr) 2fr;gap:8px 16px}.data-grid dt{font-weight:800}.data-grid dd{margin:0}
.site-footer-v3,.unified-footer{margin:48px 0 0;padding:24px 0;border-top:1px solid var(--line,#d7dfdc);display:block!important;position:static!important}
.site-footer-v3 nav{display:flex;gap:14px;flex-wrap:wrap}.site-footer-v3 a{color:inherit}
.quick-element,.quick-card,.element-drawer,.element-modal,.mobile-dock,.mobile-nav,.bottom-nav{display:none}
.quick-element.open,.quick-card.open,.element-drawer.open,.element-modal.open{display:block}
@media(max-width:800px){
 .page,.signature-home{width:min(100% - 20px,1180px)}
 .sig-nav>a{display:none}
 .hero,.sig-hero{grid-template-columns:1fr;padding:26px 0}
 .language-panel{position:fixed;left:10px;right:10px;top:72px;width:auto;max-height:calc(100vh - 92px)}
 .language-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
 .language-panel-head{grid-template-columns:1fr}.language-panel-head strong{display:none}
 .table-stage{padding:12px}
}
@media(max-width:430px){.language-grid{grid-template-columns:1fr}.language-selector summary span{max-width:125px;overflow:hidden;text-overflow:ellipsis}}


/* V6.62 pedagogical Mendeleev mascot */
.mascot-note{display:grid;grid-template-columns:92px 1fr;gap:18px;align-items:start;margin:22px 0;padding:18px;border:1px solid var(--line,#d7dfdc);border-radius:18px;background:linear-gradient(135deg,var(--surface,#fff),var(--soft,#edf5f2))}
.mascot-note p{max-width:72ch}.mascot-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin-top:10px}.mascot-grid>div{padding:12px;border:1px solid var(--line,#d7dfdc);border-radius:12px;background:var(--surface,#fff)}
.mascot-mendeleev{position:relative;width:76px;height:98px;margin:auto}
.mascot-mendeleev .face{position:absolute;left:18px;top:18px;width:40px;height:42px;border:2px solid currentColor;border-radius:45% 45% 50% 50%}
.mascot-mendeleev .hair{position:absolute;left:11px;top:5px;width:54px;height:30px;border:3px solid currentColor;border-bottom:0;border-radius:55% 55% 20% 20%;transform:rotate(-5deg)}
.mascot-mendeleev .beard{position:absolute;left:19px;top:48px;width:40px;height:34px;border:3px solid currentColor;border-top:0;border-radius:0 0 60% 60%}
.mascot-mendeleev .coat{position:absolute;left:8px;bottom:0;width:60px;height:38px;border:2px solid currentColor;border-radius:22px 22px 6px 6px}
@media(max-width:640px){.mascot-note{grid-template-columns:1fr}.mascot-grid{grid-template-columns:1fr}.mascot-mendeleev{margin-left:0}}

/* V6.63 editorial depth */
.v663-depth{margin:22px 0;padding:20px;border:1px solid var(--line,#d7dfdc);border-radius:18px;background:var(--surface,#fff)}.v663-depth h2{margin-top:0}.v663-example{margin:16px 0;padding:14px 16px;border-left:4px solid currentColor;background:var(--soft,#edf5f2);border-radius:0 12px 12px 0}.v663-example h3{margin-top:0}

/* V6.64 science paths */
.v664-path{max-width:820px;margin:30px auto}.v664-path .lead{font-size:1.18rem;max-width:68ch}.v664-path section{margin:24px 0}.v664-path .path-example{padding:18px;border:1px solid var(--line,#d7dfdc);border-radius:16px;background:var(--soft,#edf5f2)}

/* V6.65 science lab + tutorials */
.lab-page,.guide-page{max-width:850px;margin:28px auto}.lab-formula,.lab-widget{margin:20px 0;padding:18px;border:1px solid var(--line,#d7dfdc);border-radius:16px;background:var(--surface,#fff)}.formula{font-size:clamp(1.5rem,4vw,2.6rem);font-weight:800;letter-spacing:-.03em}.lab-widget{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.lab-widget label{display:grid;gap:6px}.lab-widget input{padding:10px;border:1px solid var(--line,#d7dfdc);border-radius:9px}.lab-widget button,.lab-widget output{padding:11px 14px;border-radius:10px}.lab-widget output{background:var(--soft,#edf5f2);font-weight:800}.guide-step{display:grid;grid-template-columns:42px 1fr;gap:14px;margin:20px 0}.guide-step>b{display:grid;place-items:center;width:38px;height:38px;border:2px solid currentColor;border-radius:50%}.guide-step h2{margin-top:0}@media(max-width:600px){.lab-widget{grid-template-columns:1fr}}

.lab-b-label.is-unused{display:none}.lab-assumption{grid-column:1/-1;font-size:.88rem;opacity:.78;margin:0}

/* V6.66 visual science */
.visual-page,.example-page{max-width:860px;margin:28px auto}.viz{position:relative;min-height:240px;margin:24px 0;border:1px solid var(--line,#d7dfdc);border-radius:20px;background:var(--surface,#fff);overflow:hidden}.atom-viz,.orbital-viz{display:grid;place-items:center}.atom-viz .nucleus,.orbital-viz .nucleus{width:42px;height:42px;border-radius:50%;border:3px solid currentColor;z-index:3}.atom-viz i,.orbital-viz i{position:absolute;border:1px solid currentColor;border-radius:50%;opacity:.45}.atom-viz .r1{width:90px;height:90px}.atom-viz .r2{width:150px;height:150px}.atom-viz .r3{width:210px;height:210px}.atom-viz .e{position:absolute;width:10px;height:10px;border-radius:50%;background:currentColor}.atom-viz .e1{transform:translate(45px)}.atom-viz .e2{transform:translate(-70px,20px)}.atom-viz .e3{transform:translate(70px,-65px)}.orbital-viz .o1{width:190px;height:72px;transform:rotate(0deg)}.orbital-viz .o2{width:190px;height:72px;transform:rotate(60deg)}.orbital-viz .o3{width:190px;height:72px;transform:rotate(120deg)}
.trend-viz{display:flex;align-items:center;justify-content:center;gap:14px}.trend-viz span{display:block;border:2px solid currentColor;border-radius:50%}.trend-viz.down span:nth-child(1){width:72px;height:72px}.trend-viz.down span:nth-child(2){width:60px;height:60px}.trend-viz.down span:nth-child(3){width:48px;height:48px}.trend-viz.down span:nth-child(4){width:38px;height:38px}.trend-viz.down span:nth-child(5){width:28px;height:28px}.trend-viz.up span:nth-child(1){width:24px;height:24px}.trend-viz.up span:nth-child(2){width:34px;height:34px}.trend-viz.up span:nth-child(3){width:46px;height:46px}.trend-viz.up span:nth-child(4){width:58px;height:58px}.trend-viz.up span:nth-child(5){width:72px;height:72px}
.gradient-viz{display:flex;align-items:stretch}.gradient-viz span{flex:1;border-right:1px solid currentColor;opacity:.18}.gradient-viz span:nth-child(2){opacity:.28}.gradient-viz span:nth-child(3){opacity:.4}.gradient-viz span:nth-child(4){opacity:.55}.gradient-viz span:nth-child(5){opacity:.75;background:currentColor}
.bond-viz{display:flex;align-items:center;justify-content:center;gap:12px}.bond-viz span{width:48px;height:48px;border:2px solid currentColor;border-radius:50%}.bond-viz i{width:70px;height:4px;background:currentColor}.bond-viz .ion{border-style:dashed}.molecule-viz{display:grid;place-items:center}.molecule-viz .center{width:52px;height:52px;border:2px solid currentColor;border-radius:50%}.molecule-viz .arm{position:absolute;width:90px;height:3px;background:currentColor;transform-origin:left center}.molecule-viz .a1{transform:translate(26px) rotate(35deg)}.molecule-viz .a2{transform:translate(26px) rotate(-35deg)}.molecule-viz .p{position:absolute;width:28px;height:28px;border:2px solid currentColor;border-radius:50%}.molecule-viz .p1{transform:translate(105px,62px)}.molecule-viz .p2{transform:translate(105px,-62px)}
.energy-viz{position:relative}.energy-viz:before{content:"";position:absolute;left:8%;right:8%;bottom:25%;height:2px;background:currentColor}.energy-viz .hill{position:absolute;left:20%;right:20%;bottom:25%;height:55%;border-top:4px solid currentColor;border-radius:50% 50% 0 0}.half-viz{display:flex;align-items:flex-end;justify-content:center;gap:16px}.half-viz span{width:70px;background:currentColor;opacity:.7}.half-viz .full{height:170px}.half-viz .half{height:85px}.half-viz .quarter{height:43px}.half-viz .eighth{height:22px}
.spectrum-viz{display:flex;align-items:stretch;justify-content:center;gap:25px;background:#111}.spectrum-viz span{width:5px;background:white}.spectrum-viz span:nth-child(2){opacity:.8}.spectrum-viz span:nth-child(3){opacity:.6}.spectrum-viz span:nth-child(4){opacity:.45}.spectrum-viz span:nth-child(5){opacity:.3}
.gas-viz span{position:absolute;width:14px;height:14px;border-radius:50%;background:currentColor}.gas-viz span:nth-child(1){left:12%;top:20%}.gas-viz span:nth-child(2){left:35%;top:68%}.gas-viz span:nth-child(3){left:60%;top:28%}.gas-viz span:nth-child(4){left:76%;top:62%}.gas-viz span:nth-child(5){left:48%;top:48%}.gas-viz span:nth-child(6){left:85%;top:18%}
.wave-viz svg{width:100%;height:100%}.wave-viz path{fill:none;stroke:currentColor;stroke-width:3}.circuit-viz .cell{position:absolute;left:12%;top:35%;width:20px;height:70px;border-left:4px solid currentColor;border-right:8px solid currentColor}.circuit-viz .wire{position:absolute;border:3px solid currentColor}.circuit-viz .w1{left:18%;right:18%;top:35%;height:0}.circuit-viz .w2{left:18%;right:18%;bottom:35%;height:0}.circuit-viz .res{position:absolute;right:20%;top:42%;width:70px;height:32px;border:3px solid currentColor}
.density-viz{display:flex;align-items:center;justify-content:center;gap:50px}.density-viz span{width:100px;height:100px;border:3px solid currentColor}.density-viz .heavy{background:repeating-linear-gradient(45deg,currentColor 0 5px,transparent 5px 10px)}.particles-viz{display:grid;grid-template-columns:repeat(8,18px);align-content:center;justify-content:center;gap:10px}.particles-viz span{width:14px;height:14px;border-radius:50%;background:currentColor}.uncertainty-viz{display:grid;align-content:center;gap:22px;padding:30px}.uncertainty-viz span{display:block;width:var(--w);height:10px;background:currentColor;position:relative}.uncertainty-viz span:after{content:"";position:absolute;right:-18px;top:-6px;width:36px;height:22px;border-left:2px solid currentColor;border-right:2px solid currentColor}
.example-hero{display:grid;grid-template-columns:120px 1fr;gap:20px;align-items:center}.example-symbol{display:grid;place-items:center;width:110px;height:110px;border:3px solid currentColor;border-radius:18px;font-size:2.5rem;font-weight:900}.example-steps{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.example-steps>div{padding:14px;border:1px solid var(--line,#d7dfdc);border-radius:14px}.example-steps b{display:grid;place-items:center;width:32px;height:32px;border:2px solid currentColor;border-radius:50%}@media(max-width:650px){.example-hero{grid-template-columns:1fr}.example-steps{grid-template-columns:1fr}}

/* V6.67 element comparison */
.compare-page{max-width:900px;margin:28px auto}.compare-page h1 span{opacity:.45;font-weight:400}.compare-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;margin:22px 0}.compare-grid>section{padding:18px;border:1px solid var(--line,#d7dfdc);border-radius:18px;background:var(--surface,#fff)}.compare-z{display:inline-grid;place-items:center;min-width:52px;height:52px;padding:0 8px;border:2px solid currentColor;border-radius:12px;font-weight:900}@media(max-width:650px){.compare-grid{grid-template-columns:1fr}}

/* V6.70 tutorial quality rebuild */
.tutorial-shell{width:min(1180px,calc(100% - 28px));margin:auto}.tutorial-header{border-bottom:1px solid var(--line,#d7dfdc)}.tutorial-breadcrumbs{margin-top:18px}.tutorial-article{max-width:980px;margin:0 auto 60px}
.tutorial-hero{display:grid;grid-template-columns:minmax(0,1.35fr) 260px;gap:30px;align-items:center;padding:42px 0 30px}.tutorial-hero h1{font-size:clamp(2.6rem,6vw,5.6rem);line-height:.96;letter-spacing:-.055em;margin:.15em 0 .25em}.tutorial-lead{font-size:1.2rem;line-height:1.65;max-width:66ch}.tutorial-meta{display:flex;gap:8px;flex-wrap:wrap;margin-top:18px}.tutorial-meta>*{padding:8px 11px;border:1px solid var(--line,#d7dfdc);border-radius:999px;text-decoration:none;color:inherit}
.official-mascot{transform:none!important;float:none!important;margin:auto!important;width:220px!important;height:258px!important}
.tutorial-chapter{display:grid;grid-template-columns:74px 1fr;gap:20px;padding:32px 0;border-top:1px solid var(--line,#d7dfdc)}.chapter-number{font-size:2.8rem;font-weight:950;letter-spacing:-.06em;opacity:.16}.tutorial-chapter p{font-size:1.08rem;line-height:1.7;max-width:76ch}
.prediction-card,.tutorial-example{display:grid;grid-template-columns:70px 1fr;gap:18px;margin:18px 0 34px;padding:22px;border:1px solid var(--line,#d7dfdc);border-radius:18px;background:var(--soft,#edf5f2)}.prediction-icon,.example-badge{display:grid;place-items:center;width:58px;height:58px;border-radius:50%;border:2px solid currentColor;font-size:1.5rem;font-weight:900}.example-badge{border-radius:14px}
.tutorial-mascot-card{position:relative;margin:34px 0;padding:28px;border:1px solid var(--line,#d7dfdc);border-radius:22px;background:var(--surface,#fff);overflow:hidden}
.tutorial-check{margin:36px 0;padding:26px;border-radius:22px;background:var(--ink,#18211f);color:var(--surface,#fff)}.check-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.check-grid>div{padding:15px;border:1px solid rgba(255,255,255,.18);border-radius:14px}.check-grid b{font-size:1.5rem}
.tutorial-deeper{display:grid;grid-template-columns:1.3fr .7fr;gap:25px;margin:36px 0;padding:28px;border-top:1px solid var(--line,#d7dfdc);border-bottom:1px solid var(--line,#d7dfdc)}.deep-links{display:grid;gap:8px;align-content:start}.deep-links a{padding:11px 13px;border:1px solid var(--line,#d7dfdc);border-radius:12px;text-decoration:none;color:inherit}.source-box{padding:18px;border:1px solid var(--line,#d7dfdc);border-radius:16px}
@media(max-width:760px){.tutorial-hero{grid-template-columns:1fr}.official-mascot{width:170px!important;height:220px!important;margin-left:0!important}.tutorial-chapter{grid-template-columns:48px 1fr}.check-grid{grid-template-columns:1fr}.tutorial-deeper{grid-template-columns:1fr}.tutorial-mascot-card{display:grid;grid-template-columns:1fr 150px}.tutorial-header .sig-nav>a{display:none}}

/* V6.79 editorial learning bridges */
.learning-bridge,.v679-curated{margin:24px 0;padding:20px;border:1px solid var(--line,#d7dfdc);border-radius:18px;background:var(--surface,#fff)}
.learning-prompt{margin-top:14px;padding:14px 16px;border-left:4px solid currentColor;background:var(--soft,#edf5f2);border-radius:0 12px 12px 0}
.v679-curated .grid{margin-top:14px}

/* V6.81 science lessons */
.lesson-page{max-width:980px;margin:auto}.lesson-page article{max-width:820px;margin:30px auto}.lesson-page h1{font-size:clamp(2.2rem,5vw,4.8rem);line-height:1;letter-spacing:-.045em}.lesson-section,.lesson-example,.lesson-check{margin:28px 0;padding:20px;border:1px solid var(--line,#d7dfdc);border-radius:18px}.lesson-example{background:var(--soft,#edf5f2)}.lesson-check{border-style:dashed}

/* V6.82 deeper lessons */
.concept-strip{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap;margin:24px 0;padding:18px;border-radius:18px;background:var(--soft,#edf5f2)}.concept-strip span{display:grid;place-items:center;min-width:64px;min-height:64px;padding:8px;border-radius:50%;background:var(--surface,#fff);border:1px solid var(--line,#d7dfdc);font-weight:800;font-size:1.1rem}.concept-strip i{font-style:normal;opacity:.55}.v682-deeper .learning-prompt{margin-top:18px}


/* ===== V6.88 tools recovery: functional converter UI ===== */
.article-shell,.page-shell{width:min(1180px,calc(100% - 32px));margin:0 auto;padding:18px 0 56px}
.simple-hero,.intent-hero{margin:22px 0;padding:28px;border:1px solid var(--border);border-radius:24px;background:var(--surface)}
.intent-hero h1,.simple-hero h1{margin:.35rem 0 .55rem;line-height:1.08}
.quick-answer{font-size:.9rem;font-weight:800;letter-spacing:.02em;color:var(--muted)}
.converter-layout{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(280px,.75fr);gap:20px;align-items:stretch;margin:22px 0}
.converter-panel,.visual-panel,.article-card{border:1px solid var(--border);border-radius:24px;background:var(--surface);box-shadow:0 12px 32px rgba(15,23,42,.06)}
.converter-panel{padding:24px}
.section-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:18px;margin-bottom:22px}
.section-heading h2{margin:.2rem 0 0}
.ghost-button{display:inline-flex;align-items:center;justify-content:center;min-height:40px;padding:0 14px;border:1px solid var(--border);border-radius:999px;text-decoration:none;font-weight:750}
.field-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.field{display:block}
.field-label{display:block;margin:0 0 8px;font-size:.86rem;font-weight:800;color:var(--muted)}
.input-group{display:grid;grid-template-columns:minmax(0,1fr) auto;min-height:58px;border:1px solid var(--border);border-radius:16px;overflow:hidden;background:var(--background)}
.input-group input,.input-group output{display:flex;align-items:center;width:100%;min-width:0;padding:13px 15px;border:0;background:transparent;color:var(--text);font:inherit;font-size:1.25rem;font-weight:800;outline:0}
.input-group input:focus{box-shadow:inset 0 0 0 2px currentColor}
.input-group select{min-width:78px;padding:0 12px;border:0;border-left:1px solid var(--border);background:var(--surface);color:var(--text);font:inherit;font-weight:800}
.formula-card,.formula-box{margin-top:16px;padding:15px 17px;border-radius:15px;background:var(--soft);font-weight:800;overflow-wrap:anywhere}
.precision-note{display:flex;justify-content:space-between;gap:14px;margin-top:12px;font-size:.88rem;color:var(--muted)}
.visual-panel{padding:20px;overflow:hidden}
.visual-stage{position:relative;min-height:230px;border-radius:18px;overflow:hidden;background:var(--soft)}
.visual-caption{display:grid;gap:6px;padding-top:14px;line-height:1.55}
.visual-caption strong{font-size:1.15rem}
.caption-label{font-size:.78rem;font-weight:850;text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}
.content-grid{display:grid;grid-template-columns:minmax(0,1fr);gap:20px}
.article-content{display:grid;gap:18px}
.article-section{padding:22px;border:1px solid var(--border);border-radius:20px;background:var(--surface)}
.article-section h2{margin:.25rem 0 .8rem}
.example-card{padding:12px 14px;margin:8px 0;border-radius:12px;background:var(--soft)}
.conversion-table-wrap{overflow-x:auto}
.conversion-table{width:100%;border-collapse:collapse}
.conversion-table th,.conversion-table td{padding:10px 12px;border-bottom:1px solid var(--border);text-align:left}
.conversion-list{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:12px;margin:20px 0}
.conversion-link{display:flex;justify-content:space-between;gap:12px;padding:16px;border:1px solid var(--border);border-radius:16px;background:var(--surface);text-decoration:none;font-weight:800}
.conversion-link:hover,.ghost-button:hover{transform:translateY(-1px)}
.tools-unified-header{position:relative;z-index:50}
.language-selector{position:relative}
.language-panel{z-index:100}
@media(max-width:780px){
 .article-shell,.page-shell{width:min(100% - 20px,1180px)}
 .converter-layout,.field-grid{grid-template-columns:1fr}
 .simple-hero,.intent-hero,.converter-panel{padding:18px}
 .visual-stage{min-height:190px}
 .precision-note{display:grid}
 .tools-unified-header{align-items:flex-start}
}

/* V6.91 science lesson reading rhythm */
.lesson-page article{width:min(860px,100%);margin:0 auto}.lesson-page .lead{font-size:clamp(1.08rem,2vw,1.3rem);line-height:1.7}.lesson-section,.lesson-example,.lesson-check{margin:20px 0;padding:22px;border:1px solid var(--border);border-radius:20px;background:var(--surface)}.lesson-example{border-left:5px solid currentColor}.lesson-check{background:var(--soft)}.lesson-section h2,.lesson-example h2,.lesson-check h2{margin-top:0}.lesson-page p{line-height:1.72}@media(max-width:680px){.lesson-section,.lesson-example,.lesson-check{padding:17px;border-radius:16px}}

/* V6.95 beginner pathway */
.chemistry-course article,.path-landing,.path-grid{width:min(940px,100%);margin-inline:auto}.course-hero{display:grid;grid-template-columns:1.35fr .65fr;gap:32px;align-items:center;margin:28px 0}.course-hero .lead,.path-landing .lead{font-size:clamp(1.08rem,2vw,1.28rem);line-height:1.72}.concept-atom{position:relative;width:210px;height:210px;margin:auto;border:1px solid currentColor;border-radius:50%}.concept-atom:before,.concept-atom:after{content:"";position:absolute;inset:28px;border:1px solid currentColor;border-radius:50%;transform:rotate(55deg)}.concept-atom:after{transform:rotate(-55deg)}.concept-atom b{position:absolute;left:50%;top:50%;width:34px;height:34px;transform:translate(-50%,-50%);border-radius:50%;background:currentColor}.concept-atom i,.concept-atom span{position:absolute;width:10px;height:10px;border-radius:50%;background:currentColor}.concept-atom i{left:24px;top:98px}.concept-atom i:nth-of-type(2){right:24px;left:auto}.concept-atom span{left:98px;top:24px}.course-section,.course-example,.course-check,.mascot-note{margin:22px 0;padding:24px;border:1px solid var(--border);border-radius:22px}.course-section p,.course-example p,.course-check p,.mascot-note p{line-height:1.72}.course-example{border-left:5px solid currentColor}.mascot-note{display:flex;gap:18px;align-items:center;background:var(--soft)}.mascot-css{display:grid;place-items:center;flex:0 0 66px;height:66px;border:2px solid currentColor;border-radius:50%;font-family:serif;font-size:2rem;font-weight:700}.lesson-bottom-nav{display:flex;justify-content:space-between;gap:16px;margin:32px 0}.lesson-bottom-nav a,.path-card{padding:16px;border:1px solid var(--border);border-radius:16px;text-decoration:none}.path-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.path-card{display:flex;gap:14px;align-items:center}.path-landing{padding:38px 0 24px}@media(max-width:720px){.course-hero{grid-template-columns:1fr}.concept-atom{width:170px;height:170px}.path-grid{grid-template-columns:1fr}.course-section,.course-example,.course-check,.mascot-note{padding:18px}}

/* V6.96 pathway deepening */
.course-warning{margin:22px 0;padding:22px;border:1px dashed currentColor;border-radius:20px;background:color-mix(in srgb,var(--soft) 70%,transparent)}.course-warning h2,.course-links h2{margin-top:0}.course-links{margin:24px 0}.course-chip-row{display:flex;gap:10px;flex-wrap:wrap}.course-chip{display:inline-flex;padding:10px 13px;border:1px solid var(--border);border-radius:999px;text-decoration:none;font-weight:700}.course-chip:hover{transform:translateY(-1px)}.path-principles{width:min(940px,100%);margin:8px auto 24px;padding:22px;border:1px solid var(--border);border-radius:20px;background:var(--soft)}.path-rule{display:flex;gap:12px;flex-wrap:wrap;align-items:center;margin-top:14px;font-weight:700}.v696-deepening{background:var(--surface)}

/* V6.97 progressive mini problems */
.course-problem{display:grid;grid-template-columns:180px minmax(0,1fr);gap:22px;align-items:center;margin:22px 0;padding:22px;border:1px solid var(--border);border-radius:22px;background:var(--surface)}.course-problem h2{margin-top:0}.course-problem details{margin-top:12px}.course-problem summary{cursor:pointer;font-weight:800}.v697-scale{position:relative;width:150px;height:150px;margin:auto}.v697-scale .scale-nucleus{position:absolute;left:50%;top:50%;width:18px;height:18px;transform:translate(-50%,-50%);border-radius:50%;background:currentColor}.v697-scale .scale-ring{position:absolute;left:50%;top:50%;border:1px solid currentColor;border-radius:50%;transform:translate(-50%,-50%)}.v697-scale .r1{width:76px;height:76px}.v697-scale .r2{width:142px;height:142px}.v697-balance,.v697-ion,.v697-trend,.v697-molecule,.v697-orbitals{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap;font-weight:800}.v697-balance span,.v697-balance strong,.v697-ion span,.v697-ion strong,.v697-trend span,.v697-molecule span,.v697-orbitals span{padding:10px 12px;border:1px solid var(--border);border-radius:14px}.v697-trend .bigger{font-size:1.4rem}.v697-shells{display:flex;align-items:center;justify-content:center;gap:8px}.v697-shells i{display:grid;place-items:center;border:1px solid currentColor;border-radius:50%;font-style:normal;font-weight:800}.v697-shells i:nth-child(1){width:42px;height:42px}.v697-shells i:nth-child(2){width:64px;height:64px}.v697-shells i:nth-child(3){width:86px;height:86px}.path-next-level{width:min(940px,100%);margin:30px auto;padding:22px;border:1px solid var(--border);border-radius:20px}.path-next-level h2{margin-top:0}@media(max-width:700px){.course-problem{grid-template-columns:1fr}.course-problem>div:first-child{margin:auto}}

/* V6.98 second chemistry pathway */
.path2-visual{position:relative;width:210px;height:150px;margin:auto}.path2-visual span{position:absolute;top:50%;width:48px;height:48px;margin-top:-24px;border:2px solid currentColor;border-radius:50%}.path2-visual span:nth-child(1){left:4px}.path2-visual span:nth-child(2){left:81px}.path2-visual span:nth-child(3){right:4px}.path2-visual i{position:absolute;top:50%;width:48px;height:2px;background:currentColor}.path2-visual i:nth-of-type(1){left:48px}.path2-visual i:nth-of-type(2){right:48px}.path2-problem-mark{display:grid;place-items:center;width:70px;height:70px;border:2px solid currentColor;border-radius:50%;font-size:2rem;font-weight:800}.path-bridge,.path-level2-link{margin-top:18px}.path-level2-link{width:min(940px,100%);margin:24px auto 0}.path-level2-link a{display:inline-flex}@media(max-width:700px){.path2-visual{width:180px}.course-problem{grid-template-columns:1fr}.path2-problem-mark{margin:auto}}

/* V6.99 pathway level 2 deepening */
.v699-deepening details{margin-top:14px}.v699-deepening summary{cursor:pointer;font-weight:800}.path-skills{width:min(940px,100%);margin:8px auto 24px;padding:22px;border:1px solid var(--border);border-radius:20px;background:var(--soft)}.path-skills h2{margin-top:0}.path-skills-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.path-skills-grid span{padding:12px 14px;border:1px solid var(--border);border-radius:14px;background:var(--surface)}@media(max-width:700px){.path-skills-grid{grid-template-columns:1fr}}

/* V7.00 capstone + retrieval practice */
.v700-capstone{width:min(940px,100%);margin:34px auto;padding:26px;border:1px solid var(--border);border-radius:22px;background:var(--surface)}.v700-capstone h2{margin-top:6px}.capstone-q{margin-top:18px;padding-top:18px;border-top:1px solid var(--border)}.capstone-q h3{margin:0 0 10px;font-size:1.05rem}.capstone-q summary{cursor:pointer;font-weight:800}.v700-selfcheck{margin:24px 0;padding:18px 20px;border-left:4px solid currentColor;border-radius:0 16px 16px 0;background:var(--soft)}.v700-selfcheck p{margin-bottom:0}

/* V7.01 ion lab */
.ion-lab{margin:24px 0;padding:24px;border:1px solid var(--border);border-radius:22px;background:var(--surface)}.ion-lab h2{margin-top:0}.ion-lab-grid{display:grid;grid-template-columns:1fr 1fr 1fr;gap:14px;align-items:end}.ion-lab label{display:grid;gap:8px;font-weight:800}.ion-lab input{width:100%;padding:12px 14px;border:1px solid var(--border);border-radius:14px;background:var(--background);color:var(--text);font:inherit;font-size:1.05rem}.ion-lab-result{display:grid;gap:4px;padding:13px 15px;border-radius:16px;background:var(--soft)}.ion-lab-result span,.ion-lab-result small{color:var(--muted)}.ion-lab-result strong{font-size:1.55rem}@media(max-width:700px){.ion-lab-grid{grid-template-columns:1fr}}

/* V7.02 tools hub redesign */
.tools-hero-v702{width:min(1180px,calc(100% - 32px));margin:26px auto 20px;padding:34px;border:1px solid var(--border);border-radius:28px;background:var(--surface);box-shadow:0 14px 38px rgba(15,23,42,.07)}.tools-hero-v702 h1{margin:.35rem 0 .55rem;font-size:clamp(2rem,5vw,3.7rem);letter-spacing:-.04em;line-height:1}.tools-hero-v702 p{max-width:760px;font-size:1.08rem;line-height:1.65;color:var(--muted)}.tools-family-section{width:min(1180px,calc(100% - 32px));margin:0 auto 28px}.tools-section-head{display:flex;justify-content:space-between;align-items:end;margin:0 0 14px}.tools-section-head h2{margin:.2rem 0 0}.tools-family-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:13px}.tools-family-card{display:grid;grid-template-columns:auto minmax(0,1fr) auto;gap:14px;align-items:center;min-height:92px;padding:16px;border:1px solid var(--border);border-radius:19px;background:var(--surface);text-decoration:none;box-shadow:0 8px 22px rgba(15,23,42,.035);transition:transform .16s ease,box-shadow .16s ease}.tools-family-card:hover{transform:translateY(-2px);box-shadow:0 12px 28px rgba(15,23,42,.08)}.tools-family-symbol{display:grid;place-items:center;min-width:48px;height:48px;padding:0 8px;border-radius:14px;background:var(--soft);font-weight:850;font-size:.9rem}.tools-family-card strong{display:block;font-size:1.02rem}.tools-family-card small{display:block;margin-top:5px;color:var(--muted)}.tools-family-card b{font-size:1.2rem}.tools-unified-header+main [data-v702-legacy="1"],main>[data-v702-legacy="1"]{display:none!important}
@media(max-width:900px){.tools-family-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:580px){.tools-hero-v702,.tools-family-section{width:min(100% - 20px,1180px)}.tools-hero-v702{padding:22px}.tools-family-grid{grid-template-columns:1fr}.tools-family-card{min-height:78px}}

/* V7.03 shell lab */
.shell-lab{margin:24px 0;padding:24px;border:1px solid var(--border);border-radius:22px;background:var(--surface)}.shell-lab h2{margin-top:0}.shell-lab-grid{display:grid;grid-template-columns:minmax(180px,.7fr) 220px minmax(180px,.8fr);gap:20px;align-items:center}.shell-lab label{display:grid;gap:8px;font-weight:800}.shell-lab input{padding:12px 14px;border:1px solid var(--border);border-radius:14px;background:var(--background);color:var(--text);font:inherit}.shell-lab-visual{position:relative;width:200px;height:200px;margin:auto}.shell-lab-visual>b{position:absolute;left:50%;top:50%;width:24px;height:24px;transform:translate(-50%,-50%);border-radius:50%;background:currentColor}.sl-ring{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);border:1px solid currentColor;border-radius:50%}.sl-ring i{position:absolute;right:-11px;top:50%;transform:translateY(-50%);display:grid;place-items:center;width:24px;height:24px;border-radius:50%;background:var(--surface);border:1px solid currentColor;font-style:normal;font-size:.75rem;font-weight:800}.sl1{width:70px;height:70px}.sl2{width:125px;height:125px}.sl3{width:185px;height:185px}.shell-lab-result{display:grid;gap:5px;padding:15px;border-radius:16px;background:var(--soft)}.shell-lab-result strong{font-size:1.4rem}.shell-lab-result small{color:var(--muted);line-height:1.4}@media(max-width:760px){.shell-lab-grid{grid-template-columns:1fr}.shell-lab-visual{width:180px;height:180px}.sl3{width:165px;height:165px}}

/* V7.04 editorial tip mascot */
.v700-selfcheck details{margin-top:12px;padding-top:12px;border-top:1px solid var(--border)}.v700-selfcheck summary{cursor:pointer;font-weight:850}.v700-selfcheck details p{margin:.8rem 0 0}.editorial-tip{display:grid;grid-template-columns:42px minmax(0,1fr);gap:12px;align-items:start;margin:20px 0;padding:15px 17px;border:1px solid var(--border);border-radius:17px;background:var(--surface)}.editorial-tip strong{display:block;margin:1px 0 4px}.editorial-tip p{margin:0;color:var(--muted);line-height:1.55}.mini-mendeleev{position:relative;width:38px;height:38px;border-radius:50%;background:var(--soft);overflow:hidden;border:1px solid var(--border)}.mini-mendeleev:before{content:"";position:absolute;width:18px;height:20px;left:10px;top:7px;border-radius:48% 48% 44% 44%;background:currentColor;opacity:.75}.mini-mendeleev:after{content:"";position:absolute;width:26px;height:15px;left:6px;top:24px;border-radius:50% 50% 35% 35%;background:currentColor;opacity:.25}.mini-mendeleev i:before,.mini-mendeleev i:after{content:"";position:absolute;top:14px;width:3px;height:3px;border-radius:50%;background:var(--surface);z-index:2}.mini-mendeleev i:before{left:15px}.mini-mendeleev i:after{right:15px}

/* V7.05 standalone explanatory shell laboratory */
.shell-lab-v705{margin:30px 0;padding:clamp(20px,4vw,34px);border:1px solid var(--border);border-radius:26px;background:var(--surface)}.shell-lab-v705 h2{margin:.35rem 0 .7rem;font-size:clamp(1.55rem,3vw,2.25rem)}.shell-lab-intro{max-width:850px;line-height:1.7}.shell-lab-control{display:grid;grid-template-columns:minmax(180px,1fr) minmax(220px,2fr) 52px;gap:14px;align-items:center;margin:22px 0;padding:14px 16px;border-radius:16px;background:var(--soft)}.shell-lab-control label{font-weight:800}.shell-lab-control output{font-size:1.35rem;font-weight:900;text-align:center}.shell-lab-stage{display:grid;grid-template-columns:145px 260px minmax(200px,1fr);gap:22px;align-items:center;margin:24px 0}.shell-element-card{display:grid;grid-template-columns:auto 1fr;gap:3px 9px;padding:15px;border:1px solid var(--border);border-radius:18px}.shell-element-card>span{grid-row:1/3;font-size:.85rem}.shell-element-card>strong{font-size:2rem;line-height:1}.shell-element-card>b,.shell-element-card>small{grid-column:1/-1}.shell-element-card small{color:var(--muted)}.shell-visual-v705{position:relative;width:250px;height:250px;margin:auto}.shell-visual-v705 .nucleus{position:absolute;z-index:5;left:50%;top:50%;display:grid;place-items:center;width:28px;height:28px;transform:translate(-50%,-50%);border-radius:50%;background:var(--text);color:var(--surface)}.shell-visual-v705 .ring{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);border:1px solid currentColor;border-radius:50%;opacity:.82}.shell-visual-v705 .ring i{position:absolute;right:-13px;top:50%;transform:translateY(-50%);display:grid;place-items:center;width:26px;height:26px;border-radius:50%;background:var(--surface);border:1px solid currentColor;font-style:normal;font-size:.75rem;font-weight:900}.shell-visual-v705 .ring.empty{opacity:.18}.shell-visual-v705 .r1{width:62px;height:62px}.shell-visual-v705 .r2{width:112px;height:112px}.shell-visual-v705 .r3{width:168px;height:168px}.shell-visual-v705 .r4{width:226px;height:226px}.shell-reading{display:grid;gap:7px}.shell-reading>span{font-size:.82rem;color:var(--muted);text-transform:uppercase;letter-spacing:.06em}.shell-reading>strong{font-size:clamp(1.6rem,4vw,2.5rem)}.shell-reading p{line-height:1.55}.shell-explain-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:24px 0}.shell-explain-grid article{padding:16px;border:1px solid var(--border);border-radius:17px}.shell-explain-grid p{margin:.55rem 0 0;color:var(--muted);line-height:1.55}.shell-compare,.shell-why{margin:16px 0;padding:16px 18px;border-radius:17px;background:var(--soft)}.shell-compare:empty{display:none}.shell-compare p,.shell-why p{margin:.5rem 0 0;line-height:1.6}.shell-links{display:flex;flex-wrap:wrap;gap:10px;margin:20px 0}.shell-links a{padding:10px 13px;border:1px solid var(--border);border-radius:12px;text-decoration:none;font-weight:750}.shell-model-note{font-size:.9rem;color:var(--muted);line-height:1.55;margin-bottom:0}@media(max-width:820px){.shell-lab-stage{grid-template-columns:1fr 1fr}.shell-reading{grid-column:1/-1}.shell-explain-grid{grid-template-columns:1fr}.shell-lab-control{grid-template-columns:1fr 52px}.shell-lab-control label{grid-column:1/-1}}@media(max-width:520px){.shell-lab-stage{grid-template-columns:1fr}.shell-visual-v705{width:230px;height:230px}.shell-element-card{max-width:180px}.shell-lab-control{grid-template-columns:1fr 44px}}

/* V7.06 — exact official Mendeleev portrait, mini scale in editorial advice */
.editorial-tip{grid-template-columns:48px minmax(0,1fr)!important;align-items:center!important}
.mini-official-mascot{position:relative;display:block;width:44px;height:56px;overflow:hidden}
.mini-official-mascot .mendeleev-person{position:absolute!important;left:0!important;top:0!important;width:174px!important;height:238px!important;transform:scale(.235)!important;transform-origin:top left!important}
.mini-official-mascot .mendeleev-person .coat,.mini-official-mascot .mendeleev-person .shirt,.mini-official-mascot .mendeleev-person .hair-left,.mini-official-mascot .mendeleev-person .hair-right,.mini-official-mascot .mendeleev-person .crown,.mini-official-mascot .mendeleev-person .head,.mini-official-mascot .mendeleev-person .nose,.mini-official-mascot .mendeleev-person .smile,.mini-official-mascot .mendeleev-person .beard{display:block}
@media(max-width:520px){.editorial-tip{grid-template-columns:44px minmax(0,1fr)!important}}

/* V7.07 notation decoder */
.notation-decoder{margin:26px 0;padding:clamp(18px,3vw,28px);border:1px solid var(--border);border-radius:22px;background:var(--surface)}
.notation-decoder h2{margin:.35rem 0 .65rem;font-size:clamp(1.35rem,2.5vw,1.9rem)}
.notation-decoder p{max-width:850px;line-height:1.68}
.notation-decoder a{font-weight:800;text-decoration-thickness:1px;text-underline-offset:3px}

/* V7.08 deep lesson narrative — shell-lab editorial standard */
.deep-lesson-module{margin:30px 0;padding:clamp(20px,4vw,34px);border:1px solid var(--border);border-radius:26px;background:var(--surface)}
.deep-lesson-module h2{margin:.35rem 0 .75rem;font-size:clamp(1.55rem,3vw,2.25rem);max-width:900px}
.deep-lesson-module>p{max-width:900px;line-height:1.72}
.concept-steps{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:24px 0}
.concept-steps article{padding:17px;border:1px solid var(--border);border-radius:17px;background:var(--surface)}
.concept-steps b{display:block;margin-bottom:7px;font-size:1.02rem}
.concept-steps p{margin:0;color:var(--muted);line-height:1.58}
.worked-example,.why-it-matters{margin:16px 0;padding:18px 20px;border-radius:18px;background:var(--soft)}
.worked-example strong,.why-it-matters strong{font-size:1.05rem}
.worked-example p,.why-it-matters p{margin:.55rem 0 0;line-height:1.65}
.lesson-bridge{margin-top:20px!important}.lesson-bridge a{font-weight:800;text-underline-offset:3px}
@media(max-width:760px){.concept-steps{grid-template-columns:1fr}}

/* V7.09 teaching visuals */
.element-teaching-row{display:grid;grid-template-columns:150px minmax(0,1fr);gap:24px;align-items:center;margin:20px 0;padding:20px;border:1px solid var(--border);border-radius:22px;background:var(--surface)}
.mini-element-tile{width:130px;aspect-ratio:1;display:grid;grid-template:22px 1fr 22px 18px/1fr;padding:10px;border:2px solid currentColor;border-radius:14px;text-align:center;background:var(--soft)}
.mini-element-tile .tile-z{text-align:left;font-weight:800}.mini-element-tile strong{font-size:3rem;line-height:1;align-self:center}.mini-element-tile .tile-name{font-weight:800}.mini-element-tile .tile-mass{font-size:.78rem;color:var(--muted)}
.notation-history{margin:20px 0;padding:20px;border:1px solid var(--border);border-radius:18px;background:var(--soft)}
.letter-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin:16px 0}.letter-grid>div{padding:14px;text-align:center;border:1px solid var(--border);border-radius:14px;background:var(--surface)}.letter-grid strong{display:block;font-size:1.8rem}.letter-grid span,.letter-grid small{display:block}
@media(max-width:650px){.element-teaching-row{grid-template-columns:1fr}.mini-element-tile{margin:auto}.letter-grid{grid-template-columns:repeat(2,1fr)}}

/* V7.10 varied lesson heroes — one visual metaphor per lesson */
.lesson-title-scene{display:grid;grid-template-columns:minmax(0,1fr) minmax(210px,310px);gap:clamp(18px,4vw,44px);align-items:center;margin-bottom:20px}
.lesson-title-copy h1{margin-bottom:0}.lesson-hero-art{position:relative;height:180px;border:1px solid var(--border);border-radius:26px;background:linear-gradient(145deg,var(--surface),var(--soft));overflow:hidden}
.hero-atom .nucleus{position:absolute;left:50%;top:50%;width:48px;height:48px;transform:translate(-50%,-50%);display:grid;grid-template-columns:1fr 1fr;gap:2px}.hero-atom .nucleus i{border-radius:50%;background:currentColor;opacity:.72}
.hero-atom .orbit,.hero-shells .shell-ring{position:absolute;left:50%;top:50%;border:1px solid currentColor;border-radius:50%;opacity:.35;transform:translate(-50%,-50%) rotate(-20deg)}.hero-atom .o1{width:150px;height:58px}.hero-atom .o2{width:80px;height:155px;transform:translate(-50%,-50%) rotate(35deg)}
.lesson-hero-art .electron{position:absolute;width:11px;height:11px;border-radius:50%;background:currentColor}.hero-atom .e1{left:21%;top:37%}.hero-atom .e2{right:20%;bottom:35%}.hero-atom .e3{left:57%;top:8%}
.hero-particles{display:flex;align-items:center;justify-content:center;gap:9px}.particle{display:grid;place-items:center;width:58px;height:58px;border-radius:50%;border:2px solid currentColor;font-size:1.25rem;font-weight:900}.particle.neutron{opacity:.7}.electron-card{border-style:dashed}.particle-arrow{font-weight:900;opacity:.35}
.hero-shells .shell-ring{transform:translate(-50%,-50%)}.hero-shells .r1{width:52px;height:52px}.hero-shells .r2{width:104px;height:104px}.hero-shells .r3{width:158px;height:158px}.shell-core{position:absolute;left:50%;top:50%;width:24px;height:24px;transform:translate(-50%,-50%);border-radius:50%;background:currentColor}.hero-shells .se1{left:47%;top:34%}.hero-shells .se2{left:72%;top:48%}.hero-shells .se3{left:23%;top:47%}.hero-shells .se4{left:47%;top:5%}
.hero-configuration{padding:25px 28px;display:flex;flex-direction:column;justify-content:center;gap:10px}.orbital-row{display:grid;grid-template-columns:38px 1fr;align-items:center;gap:10px}.orbital-row i{font-style:normal;font-weight:900}.orbital-row b{padding:6px 10px;border:1px solid var(--border);border-radius:8px;letter-spacing:5px}.config-caption{margin-top:5px;font-size:.78rem;opacity:.68}
.hero-periodic{display:grid;place-items:center}.periodic-mini{width:210px;display:grid;grid-template-columns:repeat(6,1fr);gap:5px;transform:rotate(-2deg)}.periodic-mini i{height:24px;border:1px solid currentColor;border-radius:4px;opacity:.35}.periodic-mini .c1,.periodic-mini .c7,.periodic-mini .c13{opacity:1;background:var(--soft)}
.hero-ions{display:flex;align-items:center;justify-content:center;gap:12px}.ion-card{width:78px;height:88px;display:grid;place-items:center;border:2px solid currentColor;border-radius:15px;font-size:1.7rem;font-weight:900}.ion-card small{display:block;font-size:.62rem;font-weight:700;opacity:.65}.ion-arrow{font-size:.85rem;font-weight:900}.ion-card.positive{border-style:dashed}
.hero-bond{display:flex;align-items:center;justify-content:center}.bond-atom{width:58px;height:58px;display:grid;place-items:center;border:2px solid currentColor;border-radius:50%;font-size:1.4rem;font-weight:900}.bond-line{width:65px;border-top:3px solid currentColor}.bond-pair{position:absolute;letter-spacing:5px;transform:translateY(-16px);font-weight:900}
@media(max-width:720px){.lesson-title-scene{grid-template-columns:1fr}.lesson-hero-art{height:150px;max-width:420px;width:100%}}

/* V7.12.1 precise in-place hero replacement */
.course-hero>.lesson-hero-art{
  width:100%;
  min-width:0;
  height:180px;
  margin:0;
}
@media(max-width:720px){
  .course-hero>.lesson-hero-art{height:150px}
}

/* V7.13 hero/content axis alignment */
.chemistry-course .course-hero{
  padding-inline:24px;
}
.chemistry-course .course-hero>.lesson-hero-art{
  margin-right:0;
}
@media(max-width:700px){
  .chemistry-course .course-hero{
    padding-inline:18px;
  }
}

/* V7.16 lesson lab cards */
.lesson-lab-card{margin:26px 0;padding:clamp(18px,3vw,28px);border:1px solid var(--border);border-radius:22px;background:var(--surface)}
.lesson-lab-card h2{margin:.35rem 0 .7rem;font-size:clamp(1.4rem,2.6vw,2rem)}
.lesson-lab-card p{line-height:1.68}
.lesson-lab-card label{display:grid;gap:6px;margin:12px 0;font-weight:750}
.lesson-lab-card input{max-width:220px;padding:9px 11px;border:1px solid var(--border);border-radius:10px;background:var(--surface);color:inherit}
.lab-result{display:grid;gap:5px;margin-top:14px;padding:14px 16px;border-radius:14px;background:var(--soft)}
.lab-result span{font-size:.82rem;color:var(--muted);text-transform:uppercase;letter-spacing:.05em}
.lab-result strong{font-size:1.45rem}.model-note{font-size:.9rem;color:var(--muted)}

/* V7.17 legacy learning upgrades */
.legacy-upgrade-card{margin:28px 0;padding:clamp(20px,3.5vw,30px);border:1px solid var(--border);border-radius:24px;background:var(--surface)}
.legacy-upgrade-card h2{margin:.35rem 0 .7rem;font-size:clamp(1.45rem,2.7vw,2.05rem)}.legacy-upgrade-card p{line-height:1.7}
.trend-mini-visual,.redox-mini-visual{margin:18px 0;padding:18px;border-radius:18px;background:var(--soft);border:1px solid var(--border)}
.trend-grid{display:grid;grid-template-columns:repeat(6,1fr);gap:5px;max-width:320px;margin:14px auto}.trend-grid i{height:24px;border:1px solid currentColor;border-radius:4px;opacity:.3}
.trend-mini-visual .arrow{display:inline-block;margin:4px 10px 4px 0;font-weight:800}.redox-mini-visual{display:flex;align-items:center;justify-content:center;gap:18px;flex-wrap:wrap}
.redox-mini-visual .species{display:grid;place-items:center;width:72px;height:72px;border:2px solid currentColor;border-radius:16px;font-weight:900;font-size:1.25rem}
.redox-mini-visual .electron-flow{font-weight:900}.redox-result{flex-basis:100%;text-align:center;font-weight:800}

/* V7.18 strong learning pass */
.strong-upgrade-card,.learning-route-map{margin:28px 0;padding:clamp(20px,3.5vw,32px);border:1px solid var(--border);border-radius:24px;background:var(--surface)}
.strong-upgrade-card h2,.learning-route-map h2{margin:.35rem 0 .8rem;font-size:clamp(1.45rem,2.8vw,2.1rem)}
.strong-upgrade-card p,.learning-route-map p{line-height:1.7}
.transfer-question{margin-top:18px;padding:15px 17px;border-radius:15px;background:var(--soft);border-left:4px solid currentColor}
.transfer-question p{margin:.35rem 0 0}.route-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin-top:18px}
.route-grid article{padding:18px;border:1px solid var(--border);border-radius:18px;background:var(--soft)}
.route-grid strong{display:block;font-size:1.08rem}.route-grid a{font-weight:800}
@media(max-width:760px){.route-grid{grid-template-columns:1fr}}


/* V7.19 new foundational lessons */
.course-page{width:min(1120px,calc(100% - 32px));margin:0 auto;padding:24px 0 60px}
.course-hero{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:24px;align-items:center;margin:24px 0 30px}
.course-hero .lead{font-size:clamp(1.05rem,2vw,1.28rem);line-height:1.65;max-width:760px}
.lesson-symbol{display:grid;place-items:center;width:92px;height:92px;border:2px solid currentColor;border-radius:20px;font-size:1.8rem;font-weight:900}
.lesson-section{margin:28px 0}
.lesson-link-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin-top:18px}
.lesson-link-grid a{padding:13px 14px;border:1px solid var(--border);border-radius:14px;background:var(--soft);font-weight:750}
.new-lessons-index{margin:30px 0;padding:clamp(20px,3vw,30px);border:1px solid var(--border);border-radius:24px}
.breadcrumb{font-size:.9rem;color:var(--muted)}
@media(max-width:760px){.course-hero{grid-template-columns:1fr}.lesson-symbol{width:70px;height:70px}.lesson-link-grid{grid-template-columns:1fr 1fr}}
@media(max-width:460px){.lesson-link-grid{grid-template-columns:1fr}}

/* V7.21 refined lesson design */
.lesson-shell{width:min(980px,calc(100% - 32px));margin:0 auto}
.course-hero-refined{display:grid;grid-template-columns:minmax(0,1fr) 230px;gap:28px;align-items:center;margin:18px 0 30px;padding:24px;border:1px solid var(--border);border-radius:24px;background:var(--surface)}
.course-hero-copy h1{margin:.25rem 0 .6rem;font-size:clamp(2rem,4vw,3.25rem)}
.course-hero-copy .lead{margin:0;max-width:700px;font-size:clamp(1.05rem,2vw,1.24rem);line-height:1.62}
.lesson-hero-art{height:150px;position:relative;border:1px solid var(--border);border-radius:20px;background:var(--soft);overflow:hidden}
.lesson-section{margin:26px 0}.rich-section h2,.intro-section h2,.links-section h2{margin-bottom:.5rem;font-size:clamp(1.35rem,2.4vw,1.8rem)}
.rich-section p,.intro-section p,.guided-example p,.rephrase-box p,.editorial-tip-mascot p{line-height:1.75}
.guided-example{margin:28px 0;padding:22px 24px;border:1px solid var(--border);border-radius:20px;background:var(--soft)}
.guided-example h2{margin:.3rem 0 .6rem}.rephrase-box{margin:24px 0;padding:18px 20px;border-left:4px solid currentColor;border-radius:14px;background:var(--surface)}
.editorial-tip-mascot{display:grid;grid-template-columns:58px minmax(0,1fr);gap:14px;align-items:start;margin:28px 0;padding:18px 20px;border:1px solid var(--border);border-radius:18px;background:var(--surface)}
.tip-mascot{width:50px;height:50px;display:grid;place-items:center;overflow:hidden}.tip-mascot .mini-official-mascot{transform:scale(.58);transform-origin:center}

/* specific heroes */
.zones-map{position:absolute;inset:18px;display:grid;grid-template-columns:1.2fr .35fr 1fr;gap:7px}.zones-map span{border-radius:12px;border:1px solid currentColor}.z-metal{opacity:.18}.z-metalloid{opacity:.42;transform:skewY(-12deg)}.z-nonmetal{opacity:.7}
.periodic-columns{position:absolute;inset:20px;display:grid;grid-template-columns:repeat(6,1fr);gap:5px}.periodic-columns i{border:1px solid currentColor;border-radius:4px;opacity:.22}.group-highlight{position:absolute;top:18px;bottom:18px;left:31px;width:25px;border:2px solid currentColor;border-radius:8px}
.family-stack{height:100%;display:flex;align-items:center;justify-content:center;gap:12px}.family-stack span{display:grid;place-items:center;width:54px;height:54px;border:2px solid currentColor;border-radius:12px;font-weight:900}.family-stack span:nth-child(2){transform:translateY(12px)}.family-stack span:nth-child(3){transform:translateY(24px)}
.halogen-pair{height:100%;display:flex;align-items:center;justify-content:center;gap:12px}.halogen-pair span{display:grid;place-items:center;width:58px;height:58px;border:2px solid currentColor;border-radius:50%;font-weight:900}.halogen-pair b{letter-spacing:3px}.electron-pull{position:absolute;right:18px;top:18px;font-weight:900}
.closed-shell{position:absolute;inset:0}.closed-shell .core{position:absolute;width:22px;height:22px;border-radius:50%;background:currentColor;left:104px;top:64px}.closed-shell .ring{position:absolute;border:1px solid currentColor;border-radius:50%;left:50%;top:50%;transform:translate(-50%,-50%)}.closed-shell .r1{width:70px;height:70px}.closed-shell .r2{width:125px;height:125px}.closed-shell .e{position:absolute;width:9px;height:9px;border-radius:50%;background:currentColor}.closed-shell .e0{left:108px;top:15px}.closed-shell .e1{left:108px;bottom:15px}.closed-shell .e2{left:45px;top:70px}.closed-shell .e3{right:45px;top:70px}.closed-shell .e4{left:61px;top:30px}.closed-shell .e5{right:61px;top:30px}.closed-shell .e6{left:61px;bottom:30px}.closed-shell .e7{right:61px;bottom:30px}
.balance-visual{height:100%;display:grid;grid-template-columns:1fr 50px 1fr;align-items:center;text-align:center;font-weight:800}.balance-visual .scale{height:2px;background:currentColor;position:relative}.balance-visual .scale:after{content:"";position:absolute;width:2px;height:45px;background:currentColor;left:50%;top:0}.balance-visual .grams{font-size:1.15rem}
.equation-visual{height:100%;display:flex;align-items:center;justify-content:center;gap:10px;font-weight:900;flex-wrap:wrap}.equation-visual span{padding:8px 10px;border:1px solid var(--border);border-radius:10px;background:var(--surface)}

@media(max-width:720px){
 .lesson-shell{width:min(100% - 24px,980px)}
 .course-hero-refined{grid-template-columns:1fr;gap:12px;padding:16px;margin-top:12px}
 .lesson-hero-art{height:58px}
 .course-hero-copy h1{font-size:clamp(1.9rem,9vw,2.6rem)}
 .editorial-tip-mascot{grid-template-columns:46px minmax(0,1fr);padding:15px}
 .tip-mascot{width:42px;height:42px}
 .zones-map{inset:9px}.periodic-columns{inset:8px}.family-stack span{width:38px;height:38px}.family-stack span:nth-child(2),.family-stack span:nth-child(3){transform:none}
 .halogen-pair span{width:38px;height:38px}.electron-pull{top:7px;right:10px}
 .closed-shell .core{left:calc(50% - 11px);top:18px}.closed-shell .r1{width:40px;height:40px}.closed-shell .r2{width:78px;height:50px}.closed-shell .e{display:none}
 .balance-visual{font-size:.78rem}.equation-visual{font-size:.78rem;gap:5px}.equation-visual span{padding:5px 7px}
}

/* V8.00 global quality layer */
.hero-science-v8{display:grid!important;grid-template-columns:1.25fr 1fr;grid-template-rows:repeat(3,1fr);gap:8px;min-height:290px;padding:18px}.hero-element-cell{grid-row:1/4;display:grid;grid-template-columns:1fr auto;grid-template-rows:auto 1fr auto auto;padding:18px;border:1px solid var(--line);border-radius:16px;background:var(--paper)}.hero-element-cell>span{font-size:.8rem}.hero-element-cell>b{grid-column:1/-1;align-self:center;font-size:clamp(4rem,7vw,6rem);line-height:1}.hero-element-cell>small,.hero-element-cell>em{grid-column:1/-1}.hero-element-cell>small{font-weight:800}.hero-element-cell>em{font-style:normal;color:var(--muted);font-size:.8rem;margin-top:3px}.hero-stat{display:flex;align-items:baseline;gap:10px;padding:10px 12px;border-bottom:1px solid var(--line)}.hero-stat strong{font-size:1.65rem}.hero-stat span{font-size:.72rem;line-height:1.3;color:var(--muted)}
.signature-story,.periodic-proof,.science-desk,.home-v8-local-story,.home-v8-local-journey{max-width:1240px;margin-left:auto;margin-right:auto}.signature-story{margin-top:54px;padding:50px 24px;display:grid;grid-template-columns:minmax(0,1.45fr) minmax(280px,.55fr);gap:48px;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.story-copy{max-width:780px}.story-copy h2{font-size:clamp(2.5rem,5vw,4.6rem);line-height:1;letter-spacing:-.045em;margin:.22em 0 .38em}.story-copy p{font-size:1rem;line-height:1.75}.story-links{display:flex;gap:22px;flex-wrap:wrap;margin-top:22px}.story-links a{font-weight:850}.signature-portrait{min-height:360px;border-left:1px solid var(--line)}.signature-portrait .mendeleev-person{transform:translate(-50%,-48%) scale(1.18)}
.periodic-proof-v8{padding:60px 24px;display:grid;grid-template-columns:minmax(260px,.8fr) 150px minmax(300px,1fr);gap:38px;align-items:center;border-bottom:1px solid var(--line)}.proof-intro h2{font-size:clamp(2rem,4vw,3.3rem);line-height:1;margin:.25em 0}.proof-intro p,.proof-explain p{line-height:1.67;color:var(--muted)}.proof-explain a{font-weight:850}.proof-elements-vertical{display:flex!important;flex-direction:column;align-items:center;gap:5px}.proof-elements-vertical a{width:112px;height:105px;padding:9px;border:1px solid var(--line);display:grid;grid-template-columns:1fr auto;grid-template-rows:auto 1fr auto auto;text-decoration:none;background:var(--paper)}.proof-elements-vertical a b{grid-column:1/-1;font-size:2.4rem;align-self:center}.proof-elements-vertical a span,.proof-elements-vertical a em{grid-column:1/-1;font-size:.7rem}.proof-elements-vertical a em{font-style:normal;color:var(--muted)}
.science-desk-v8{padding:60px 24px;border-bottom:1px solid var(--line)}.science-desk-v8 .desk-title{display:grid;grid-template-columns:minmax(0,1fr) minmax(260px,.55fr);gap:40px;align-items:end;margin-bottom:28px}.science-desk-v8 .desk-title h2{font-size:clamp(2.4rem,4.5vw,4rem);line-height:1;margin:0}.science-desk-v8 .desk-title p{margin:0;line-height:1.6;color:var(--muted)}.desk-rows{border-top:1px solid var(--line)}.desk-rows a{display:grid;grid-template-columns:45px minmax(0,1fr) 280px;gap:20px;align-items:center;padding:20px 0;border-bottom:1px solid var(--line);text-decoration:none}.desk-rows b{font-size:.72rem;color:var(--muted)}.desk-rows strong{font-size:1.04rem}.desk-rows span{font-size:.8rem;text-align:right;color:var(--muted)}
.home-v8-local-story{display:grid;grid-template-columns:180px minmax(0,1fr);gap:28px;align-items:center;padding:42px 24px;border-top:1px solid var(--line);border-bottom:1px solid var(--line);margin-top:44px}.home-v8-local-story h2{font-size:clamp(1.9rem,3.5vw,3rem);margin:.1em 0 .4em}.home-v8-local-story p{line-height:1.7;color:var(--muted)}.compact-mendeleev{min-height:180px}.compact-mendeleev .mendeleev-person{transform:translate(-50%,-50%) scale(.72)}.home-v8-local-journey{padding:34px 24px 54px;display:grid;grid-template-columns:repeat(4,1fr);gap:12px}.home-v8-local-card{display:block;padding:18px 0;border-top:1px solid var(--line);text-decoration:none}.home-v8-local-card strong{display:block;font-size:1rem;line-height:1.35}.home-v8-local-card span{display:block;margin-top:8px;font-size:.82rem;line-height:1.55;color:var(--muted)}
/* content pages */
.lesson-page{width:min(980px,calc(100% - 32px));margin-left:auto;margin-right:auto}.lesson-page h1{font-size:clamp(2.35rem,5vw,4.6rem);line-height:1;letter-spacing:-.04em}.lesson-page>p,.lesson-page section>p{line-height:1.72}.legacy-upgrade-card,.worked-example,.strong-upgrade-card,.editorial-tip{border-radius:20px!important}.worked-example{padding:20px 22px!important}.editorial-tip{display:grid;gap:10px;padding:18px 20px!important}.element-hero{align-items:center}.element-story-card,.element-context-card,.info-card{border-radius:20px}.element-scene{max-height:360px;overflow:hidden}
/* tools */
.tools-family-grid,.theme-grid{display:grid!important;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px!important}.tools-family-card,.theme-card{border-radius:20px!important;min-width:0}.converter-shell input,.converter-shell select,.converter-card input,.converter-card select{min-height:46px;border-radius:12px}.converter-shell button,.converter-card button{min-height:44px;border-radius:999px}.language-panel{max-height:min(70vh,640px);overflow:auto}.language-grid{display:grid!important;grid-template-columns:repeat(3,minmax(0,1fr));gap:6px}.language-grid a{min-width:0}
body.dark .hero-element-cell,body.dark .home-v8-local-card{background:var(--paper)}
@media(max-width:900px){.signature-story{grid-template-columns:1fr}.signature-portrait{min-height:230px;border-left:0;border-top:1px solid var(--line)}.periodic-proof-v8{grid-template-columns:1fr 130px}.periodic-proof-v8 .proof-explain{grid-column:1/-1}.science-desk-v8 .desk-title{grid-template-columns:1fr}.home-v8-local-journey{grid-template-columns:1fr 1fr}.tools-family-grid,.theme-grid{grid-template-columns:1fr 1fr!important}.desk-rows a{grid-template-columns:35px 1fr}.desk-rows span{grid-column:2;text-align:left}}
@media(max-width:560px){.hero-science-v8{min-height:215px;padding:10px}.hero-element-cell{padding:10px}.hero-stat strong{font-size:1.2rem}.hero-stat span{font-size:.63rem}.signature-story,.periodic-proof-v8,.science-desk-v8,.home-v8-local-story,.home-v8-local-journey{padding-left:14px;padding-right:14px}.periodic-proof-v8{grid-template-columns:1fr}.proof-elements-vertical{margin:auto}.home-v8-local-story{grid-template-columns:1fr}.compact-mendeleev{display:none}.home-v8-local-journey{grid-template-columns:1fr}.tools-family-grid,.theme-grid{grid-template-columns:1fr!important}.language-grid{grid-template-columns:1fr 1fr!important}.element-hero{grid-template-columns:1fr!important}.element-scene{max-height:240px}}

/* V8.00 visual QA corrections */
.tools-unified-header{margin-bottom:22px}.tools-hero-v702{margin-top:0!important}.tools-family-section{margin-bottom:34px}.theme-grid{align-items:stretch}.theme-grid .theme-card{display:flex!important;flex-direction:column;gap:7px;padding:18px!important;border:1px solid var(--line)!important;border-radius:18px!important;background:var(--paper)!important;text-decoration:none!important;min-height:112px}.theme-grid .theme-card strong{display:block;font-size:1rem;line-height:1.3}.theme-grid .theme-card span{display:block;font-size:.82rem;line-height:1.45;color:var(--muted);margin-top:auto}.theme-grid .theme-card .eyebrow{margin-bottom:2px}.compare-theme-card{min-height:150px!important}
.lesson-page>.site-footer-v3{margin-top:46px;padding-top:24px;border-top:1px solid var(--line)}.lesson-page>.site-footer-v3 nav{display:flex;gap:14px;flex-wrap:wrap}.lesson-page>.legacy-upgrade-card,.lesson-page>.strong-upgrade-card,.lesson-page>.science-map-link-v651{margin-top:28px}.lesson-page>.legacy-upgrade-card{padding:28px!important}.lesson-page>.science-map-link-v651{padding:14px 0}
@media(max-width:700px){.theme-grid .theme-card{min-height:auto}.compare-theme-card{min-height:auto!important}.lesson-page>.legacy-upgrade-card{padding:20px!important}}

/* V8.00 final dark-mode authority */
body.dark{--ink:#f3f7f5;--paper:#17201c;--soft:#1e2a25;--bg:#0e1512;--surface:#17201c;--surface2:#1e2a25;--text:#f3f7f5;--muted:#a8b4ae;--line:#3a4a43;--green:#78e0c4;--green2:#9af2db;--mint:#17382f;color:var(--ink)!important;background:radial-gradient(circle at 93% 5%,rgba(120,224,196,.08),transparent 28%),linear-gradient(180deg,#111815,#0d1311)!important}
body.dark h1,body.dark h2,body.dark h3,body.dark h4,body.dark strong,body.dark .brand-name,body.dark .sig-brand-text strong,body.dark .table-title-row h2{color:var(--ink)!important}
body.dark .sig-nav>a,body.dark .breadcrumbs a,body.dark .site-header a{color:var(--ink)}
body.dark .hero-actions .secondary,body.dark .language-selector summary,body.dark .language-panel,body.dark .theme-card,body.dark .tools-family-card,body.dark .hero-element-cell{background:var(--surface)!important;color:var(--ink)!important;border-color:var(--line)!important}
body.dark .sig-search input,body.dark input,body.dark select{background:#111815!important;color:var(--ink)!important;border-color:var(--line)!important}
body.dark .table-stage,body.dark .table-center-card,body.dark .editorial-card,body.dark .legacy-upgrade-card,body.dark .worked-example,body.dark .element-story-card,body.dark .element-context-card{background:var(--surface)!important;color:var(--ink)!important;border-color:var(--line)!important}

/* V8.01 hide homepage hero art on mobile */
@media(max-width:640px){
  .signature-home .hero-science,
  .signature-home .hero-science-v7,
  .signature-home .hero-element-cell,
  .signature-home .hero-mini-stat{
    display:none !important;
  }
  .signature-home .sig-hero{
    grid-template-columns:1fr !important;
    min-height:auto !important;
  }
}

/* V8.01 atom structure redesign */
.atom-structure-v801{width:min(980px,calc(100% - 32px));margin:0 auto}
.atom-hero-v801{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:30px;align-items:center}
.atom-visual-v801{position:relative;height:240px;border:1px solid var(--line);border-radius:24px;background:var(--paper-2);overflow:hidden}
.atom-visual-v801 .nucleus{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);width:84px;height:84px;border-radius:50%;background:var(--paper);border:2px solid var(--ink);display:grid;place-items:center;align-content:center;font-size:.72rem;font-weight:800;z-index:3}
.atom-visual-v801 .ring{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);border:1px solid var(--ink);border-radius:50%;opacity:.35}.atom-visual-v801 .r1{width:130px;height:130px}.atom-visual-v801 .r2{width:210px;height:210px}
.atom-visual-v801 .e{position:absolute;width:12px;height:12px;border-radius:50%;background:var(--green,var(--ink));z-index:4}.atom-visual-v801 .e1{left:50%;top:47px}.atom-visual-v801 .e2{left:50%;bottom:47px}.atom-visual-v801 .e3{left:25px;top:50%}.atom-visual-v801 .e4{right:25px;top:50%}.atom-visual-v801 .e5{left:50px;top:45px}.atom-visual-v801 .e6{right:50px;bottom:45px}
.atom-trio-v801{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:28px 0}.atom-trio-v801 article{padding:20px;border:1px solid var(--line);border-radius:18px;background:var(--paper)}.atom-trio-v801 h3{margin:.5rem 0}.atom-trio-v801 p{color:var(--muted);line-height:1.65}.particle{display:grid;place-items:center;width:42px;height:42px;border-radius:50%;border:2px solid currentColor;font-weight:900}
.carbon-tile-v801{float:right;width:120px;height:135px;margin:0 0 16px 22px;padding:10px;border:2px solid var(--green,var(--ink));border-radius:14px;display:grid;grid-template-rows:auto 1fr auto auto;background:var(--paper)}.carbon-tile-v801 b{font-size:3.2rem;align-self:center}.carbon-tile-v801 span{font-weight:800}.carbon-tile-v801 em{font-style:normal;color:var(--muted);font-size:.75rem}
@media(max-width:700px){.atom-structure-v801{width:min(100% - 24px,980px)}.atom-hero-v801{grid-template-columns:1fr}.atom-visual-v801{height:110px}.atom-visual-v801 .r2{width:150px;height:90px}.atom-visual-v801 .r1{width:90px;height:70px}.atom-visual-v801 .e{display:none}.atom-trio-v801{grid-template-columns:1fr}.carbon-tile-v801{float:none;margin:0 0 18px;width:105px;height:118px}}

/* V8.02 corrections */
@media(max-width:640px){
.signature-home .hero-science,.signature-home .hero-science-v7{display:none!important}
.signature-home .sig-hero{grid-template-columns:1fr!important;min-height:auto!important}
.atom-structure-v801 .atom-visual-v801{display:none!important}
.atom-structure-v801 .atom-hero-v801{grid-template-columns:1fr!important}
}
.atom-structure-v801 .atom-visual-v801 .nucleus{font-size:.92rem;line-height:1.2}
.atom-structure-v801 .atom-visual-v801 .nucleus b{font-size:1.12rem}
.carbon-example-v802{display:grid;grid-template-columns:120px minmax(0,1fr);gap:18px;align-items:center;margin:0 0 22px}
.carbon-example-v802 .carbon-tile-v801{float:none;margin:0}
.atomic-weight-note{display:grid;gap:3px}.atomic-weight-note strong{font-size:1.55rem}.atomic-weight-note span{font-weight:800}.atomic-weight-note small{color:var(--muted);line-height:1.45}
.tool-preview-expanded{display:grid!important;grid-template-columns:1fr 1fr;gap:6px}
@media(max-width:520px){.carbon-example-v802{grid-template-columns:1fr}.tool-preview-expanded{grid-template-columns:1fr}}

/* V8.04 — language selector: no generated English label */
.language-selector .language-panel::before,
.language-panel::before{
  content:none !important;
  display:none !important;
}

/* =========================================================
   V8.10 — global convergence layer
   ========================================================= */

/* Never generate hidden/grey English language labels */
.language-selector .language-panel::before,
.language-panel::before{content:none!important;display:none!important}

/* Shared footer: useful navigation only */
.site-footer-v3.unified-footer,
.site-footer-v3{
  margin-top:42px;padding:22px 0;border-top:1px solid var(--line);
  background:transparent;color:var(--muted)
}
.site-footer-v3 nav{display:flex;gap:16px;flex-wrap:wrap}
.site-footer-v3 nav a{font-weight:750;text-decoration:none}
.site-footer-v3 p:empty{display:none}

/* Shared page width and editorial rhythm */
.page-family-learn,.page-family-elements,.page-family-tools,.page-family-science,.page-family-editorial{
  --content-max:1040px;
}
.page-family-learn main,.page-family-elements main,.page-family-tools main,.page-family-science main,.page-family-editorial main{
  scroll-margin-top:80px;
}

/* LEARN — lift legacy 3-section pages into the accepted pedagogical rhythm */
.lesson-page.v810-learn,
main.lesson-page.v810-learn{
  width:min(980px,calc(100% - 32px));margin:0 auto;padding:26px 0 60px
}
.lesson-page.v810-learn>nav:first-child{font-size:.82rem;color:var(--muted);margin-bottom:18px}
.lesson-page.v810-learn>h1{font-size:clamp(2.7rem,6vw,5.2rem);line-height:.96;letter-spacing:-.045em;margin:.15em 0 .35em}
.lesson-page.v810-learn>section{
  margin:18px 0;padding:24px;border:1px solid var(--line);border-radius:22px;background:var(--paper)
}
.lesson-page.v810-learn>section:first-of-type{background:var(--paper-2)}
.lesson-page.v810-learn>section h2{font-size:clamp(1.55rem,3vw,2.2rem);line-height:1.12;margin:.1em 0 .45em}
.lesson-page.v810-learn>section p{line-height:1.75;max-width:820px}
.lesson-page.v810-learn .science-map-link-v651{
  display:block;margin:22px 0;padding:16px 18px;border-left:4px solid var(--green,var(--ink));
  background:var(--paper-2);border-radius:0 14px 14px 0
}

/* Rich Learn pages keep their own components, but align width/spacing */
.chemistry-course,.course-page,.learning-page{
  width:min(980px,calc(100% - 32px));margin-left:auto;margin-right:auto
}
.course-hero{margin-top:20px;margin-bottom:30px}
.deep-lesson-module,.worked-example-block,.rephrase-box,.editorial-tip-mascot{margin-top:24px}

/* ELEMENTS — stronger hierarchy, less generic card feel */
.page-family-elements .element-hero{padding-top:24px}
.page-family-elements .element-title{align-items:center}
.page-family-elements .big-tile{box-shadow:none}
.page-family-elements .element-story-card h2{font-size:1.55rem;margin-top:1.7rem}
.page-family-elements .element-story-card p{line-height:1.72}
.page-family-elements .element-context-card{position:sticky;top:86px}
.page-family-elements .atomic-weight-card span{font-size:.76rem}
.page-family-elements .atomic-weight-card strong{overflow-wrap:anywhere}

/* TOOLS — eliminate visual duplication, prioritize utility then explanation */
.page-family-tools .simple-hero{max-width:820px}
.page-family-tools .conversion-list{margin-top:18px}
.page-family-tools .article-card,.page-family-tools .article-section{line-height:1.7}
.page-family-tools .tools-site-footer{display:none!important}
.page-family-tools .deep-unit-guide-v58{margin-top:28px}
.page-family-tools .conversion-card,.page-family-tools .converter-card{box-shadow:none}

/* SCIENCE / EDITORIAL */
.page-family-science article,.page-family-editorial article{line-height:1.75}
.page-family-science h1,.page-family-editorial h1{letter-spacing:-.035em}
.page-family-science h2,.page-family-editorial h2{line-height:1.12}

/* Generic advice box injected into older Learn only */
.v810-learning-note{
  margin:22px 0;padding:17px 18px;border:1px solid var(--line);
  border-radius:18px;background:var(--paper-2)
}
.v810-learning-note strong{display:block;margin-bottom:3px}
.v810-learning-note p{margin:0;color:var(--muted);line-height:1.6}

/* Mobile principle: decorative visuals disappear before content */
@media(max-width:640px){
  .signature-home .hero-science,.signature-home .hero-science-v7,.signature-home .hero-science-v8,
  .atom-visual-v801,.element-context-card .element-scene{display:none!important}
  .signature-home .sig-hero,.atom-hero-v801{grid-template-columns:1fr!important}
  .page-family-elements .element-context-card{position:static}
  .lesson-page.v810-learn,main.lesson-page.v810-learn,
  .chemistry-course,.course-page,.learning-page{width:min(100% - 24px,980px)}
}

/* V8.10.39 NL atom tip parity */
.page-family-learn .editorial-tip-mascot{
  display:grid;grid-template-columns:72px minmax(0,1fr);gap:18px;
  align-items:center;padding:20px 22px;border:1px solid var(--line);
  border-radius:20px;background:var(--paper-2);margin:24px 0
}
.page-family-learn .editorial-tip-mascot .tip-copy{min-width:0}
.page-family-learn .editorial-tip-mascot .tip-copy strong{display:block;margin-bottom:5px}
.page-family-learn .editorial-tip-mascot .tip-copy p{margin:0;line-height:1.65;max-width:none}
.page-family-learn .editorial-tip-mascot .tip-mascot{width:58px;min-width:58px}
@media(max-width:640px){
  .page-family-learn .editorial-tip-mascot{grid-template-columns:54px minmax(0,1fr);padding:16px;gap:12px}
  .page-family-learn .editorial-tip-mascot .tip-mascot{width:46px;min-width:46px}
}

/* V8.10.40 validated Learn model polish */
.page-family-learn .editorial-tip-mascot .tip-mascot{
  width:68px;min-width:68px
}
.page-family-learn .editorial-tip-mascot{
  grid-template-columns:82px minmax(0,1fr)
}
@media(max-width:640px){
  .page-family-learn .editorial-tip-mascot .tip-mascot{width:54px;min-width:54px}
  .page-family-learn .editorial-tip-mascot{grid-template-columns:62px minmax(0,1fr)}
}

/* V8.11.2 tools hub enrichment */
.tools-hub .tools-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));gap:12px;margin-top:20px}
.tools-hub .tool-card{display:flex;justify-content:space-between;align-items:center;gap:14px;padding:16px 18px;border:1px solid var(--line);border-radius:16px;background:var(--paper-2);text-decoration:none;color:inherit}
.tools-hub .tool-card:hover{transform:translateY(-1px)}

/* V8.12 auto page title */
.auto-page-title{font-size:clamp(2rem,4vw,3.5rem);line-height:1.05;letter-spacing:-.035em;margin:24px 0 20px}