.history-shell{width:min(1420px,calc(100% - 32px));margin:0 auto 64px;--history-blue:#3f82e8;--history-gold:#c68a2d;--history-green:#2f9e6f}
.history-stage{position:relative;border:1px solid var(--line);background:var(--surface);border-radius:24px;overflow:hidden;box-shadow:0 22px 60px color-mix(in srgb,var(--text) 7%,transparent)}
.history-stage::before{content:"";position:absolute;inset:0 0 auto;height:190px;pointer-events:none;background:radial-gradient(900px 180px at 20% 0%,color-mix(in srgb,var(--history-blue) 12%,transparent),transparent 70%),radial-gradient(650px 170px at 82% 0%,color-mix(in srgb,var(--history-gold) 10%,transparent),transparent 72%)}
.history-toolbar{position:relative;padding:22px 22px 18px;border-bottom:1px solid var(--line);display:grid;grid-template-columns:minmax(300px,1.2fr) minmax(320px,.8fr);gap:24px;align-items:end}
.history-year-row{display:grid;grid-template-columns:44px minmax(220px,1fr) 44px;gap:14px;align-items:center}
.history-year-row>div{display:grid;grid-template-columns:auto 1fr;gap:18px;align-items:center;min-width:0}
.history-year{font-size:clamp(2.5rem,5.5vw,5.15rem);font-weight:880;line-height:.92;letter-spacing:-.075em;font-variant-numeric:tabular-nums;min-width:4.15ch}
.history-slider{width:100%;height:28px;background:transparent;accent-color:var(--history-blue);cursor:pointer}
.history-slider::-webkit-slider-runnable-track{height:5px;border-radius:999px;background:linear-gradient(90deg,var(--history-blue) var(--history-progress,0%),color-mix(in srgb,var(--line) 70%,transparent) var(--history-progress,0%))}
.history-slider::-webkit-slider-thumb{margin-top:-6px;width:17px;height:17px;border-radius:50%;background:var(--surface);border:4px solid var(--history-blue);box-shadow:0 0 0 4px color-mix(in srgb,var(--history-blue) 12%,transparent);-webkit-appearance:none}
.history-slider::-moz-range-track{height:5px;border-radius:999px;background:var(--line)}.history-slider::-moz-range-progress{height:5px;border-radius:999px;background:var(--history-blue)}
.history-step{width:44px;height:44px;border:1px solid var(--line);border-radius:14px;background:color-mix(in srgb,var(--surface) 88%,transparent);color:var(--text);font:inherit;font-size:1.05rem;cursor:pointer;transition:transform .16s,background .16s,border-color .16s}.history-step:hover{transform:translateY(-1px);border-color:color-mix(in srgb,var(--text) 32%,var(--line));background:var(--surface-2,var(--surface))}
.history-modes{display:flex;flex-wrap:wrap;gap:8px;justify-content:flex-end}.history-modes button{border:1px solid var(--line);background:color-mix(in srgb,var(--surface) 86%,transparent);color:var(--text);border-radius:999px;padding:9px 12px;font:inherit;font-size:.86rem;cursor:pointer;transition:transform .16s,background .16s,border-color .16s}.history-modes button:hover{transform:translateY(-1px)}.history-modes button[aria-pressed="true"]{background:var(--text);color:var(--surface);border-color:var(--text)}
.history-now{position:relative;display:grid;grid-template-columns:auto 1fr;gap:14px;align-items:center;padding:13px 22px;border-bottom:1px solid var(--line);background:color-mix(in srgb,var(--surface-2,var(--surface)) 78%,transparent);min-height:57px}.history-now-year{font-size:.76rem;font-weight:800;letter-spacing:.08em;color:var(--muted);font-variant-numeric:tabular-nums}.history-now-items{display:flex;gap:7px;align-items:center;overflow:auto;scrollbar-width:none}.history-now-items::-webkit-scrollbar{display:none}.history-now-pill{display:inline-flex;align-items:center;gap:6px;white-space:nowrap;border:1px solid var(--line);background:var(--surface);border-radius:999px;padding:6px 9px;font-size:.78rem}.history-now-pill strong{font-size:.86rem}.history-now-pill.naming{border-style:dashed}.history-now-empty{color:var(--muted);font-size:.82rem}
.history-milestones{position:relative;padding:18px 22px 14px;border-bottom:1px solid var(--line);display:flex;gap:0;overflow:auto;scrollbar-width:thin}.history-milestones::before{content:"";position:absolute;left:32px;right:32px;top:25px;height:1px;background:var(--line)}.history-milestones button{position:relative;flex:0 0 auto;min-width:125px;border:0;background:transparent;color:var(--muted);padding:23px 10px 7px;font:inherit;font-size:.74rem;text-align:center;cursor:pointer;white-space:nowrap}.history-milestones button::before{content:"";position:absolute;top:2px;left:50%;width:11px;height:11px;border-radius:50%;transform:translateX(-50%);border:2px solid var(--surface);background:var(--line);box-shadow:0 0 0 1px var(--line);transition:transform .16s,background .16s}.history-milestones button:hover::before{transform:translateX(-50%) scale(1.2)}.history-milestones button[aria-current="true"]{color:var(--text);font-weight:750}.history-milestones button[aria-current="true"]::before{background:var(--history-blue);box-shadow:0 0 0 4px color-mix(in srgb,var(--history-blue) 15%,transparent)}
.history-stats{position:relative;display:grid;grid-template-columns:repeat(3,1fr);border-bottom:1px solid var(--line)}.history-stat{padding:15px 20px;border-inline-end:1px solid var(--line)}.history-stat:last-child{border-inline-end:0}.history-stat b{display:block;font-size:1.72rem;line-height:1;letter-spacing:-.045em;font-variant-numeric:tabular-nums}.history-stat small{display:block;margin-top:5px;color:var(--muted);font-size:.76rem}.history-progress-wrap{height:5px;background:color-mix(in srgb,var(--line) 64%,transparent);overflow:hidden}.history-progress-bar{height:100%;width:0;background:linear-gradient(90deg,var(--history-blue),color-mix(in srgb,var(--history-blue) 55%,var(--history-gold)));transition:width .32s cubic-bezier(.2,.8,.2,1)}
.history-main{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:0;align-items:start}.history-table-wrap{min-width:0;padding:20px;border-inline-end:1px solid var(--line);overflow:auto;background:linear-gradient(180deg,color-mix(in srgb,var(--surface) 98%,var(--history-blue) 2%),var(--surface))}.history-groups{display:grid;grid-template-columns:repeat(18,minmax(44px,1fr));gap:5px;min-width:930px;margin-bottom:6px;color:var(--muted);font-size:.66rem;text-align:center}.history-grid{display:grid;grid-template-columns:repeat(18,minmax(44px,1fr));grid-template-rows:repeat(7,68px);gap:5px;min-width:930px}.history-fblock{display:grid;grid-template-columns:54px repeat(14,minmax(44px,1fr));gap:5px;min-width:790px;margin-top:13px}.history-f-label{display:flex;align-items:center;justify-content:center;color:var(--muted);font-size:.7rem}
.hcell{position:relative;isolation:isolate;border:1px solid var(--line);border-radius:11px;background:var(--surface-2,var(--surface));color:var(--text);padding:5px;cursor:pointer;text-align:start;overflow:hidden;transition:opacity .22s,transform .22s,border-color .22s,background .22s,box-shadow .22s,filter .22s}.hcell::after{content:"";position:absolute;inset:auto 0 0;height:3px;background:transparent;transition:background .22s}.hcell:hover{transform:translateY(-2px);box-shadow:0 8px 18px color-mix(in srgb,var(--text) 8%,transparent);z-index:3}.hcell .z{font-size:.58rem;color:var(--muted);position:absolute;top:5px;inset-inline-start:6px}.hcell .sym{display:block;font-size:1.22rem;font-weight:850;line-height:1.05;text-align:center;margin-top:7px;letter-spacing:-.03em}.hcell .nm{display:block;font-size:.57rem;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;text-align:center;margin-top:4px}.hcell.unknown{opacity:.105;filter:saturate(.15) grayscale(.35)}.hcell.before1869{opacity:.82}.hcell.after1869.known-now{background:color-mix(in srgb,var(--surface) 76%,var(--history-blue) 24%);border-color:color-mix(in srgb,var(--line) 30%,var(--history-blue) 70%)}.hcell.after1869.known-now::after{background:var(--history-blue)}.hcell.predicted-gap{outline:2px dashed var(--history-gold);outline-offset:-4px;opacity:.52;background:color-mix(in srgb,var(--surface) 94%,var(--history-gold) 6%)}.hcell.predicted-confirmed{box-shadow:inset 0 0 0 2px var(--history-gold)}.hcell.predicted-confirmed::after{background:var(--history-gold)}.hcell.focus{outline:2px solid var(--text);outline-offset:2px;z-index:4;box-shadow:0 9px 22px color-mix(in srgb,var(--text) 12%,transparent)}.hcell.newly-visible{animation:historyReveal .58s cubic-bezier(.2,.8,.2,1)}@keyframes historyReveal{0%{opacity:.08;transform:scale(.84);box-shadow:0 0 0 0 color-mix(in srgb,var(--history-blue) 35%,transparent)}55%{opacity:1;transform:scale(1.07);box-shadow:0 0 0 8px color-mix(in srgb,var(--history-blue) 0%,transparent)}100%{transform:scale(1)}}
.history-legend{display:flex;flex-wrap:wrap;gap:12px;padding-top:13px;color:var(--muted);font-size:.74rem;min-width:830px}.history-key{display:inline-flex;align-items:center;gap:6px}.history-swatch{width:13px;height:13px;border:1px solid var(--line);border-radius:4px;background:var(--surface-2,var(--surface))}.history-swatch.after{background:color-mix(in srgb,var(--surface) 70%,var(--history-blue) 30%);border-color:var(--history-blue)}.history-swatch.unknown{opacity:.18}.history-swatch.pred{border:2px dashed var(--history-gold);background:transparent}
.history-panel{position:sticky;top:16px;padding:22px;min-height:430px}.history-panel .element-big{display:flex;align-items:flex-start;gap:12px}.history-panel .element-symbol{display:grid;place-items:center;width:64px;height:64px;border:1px solid var(--line);border-radius:16px;background:var(--surface-2,var(--surface));font-size:2.15rem;font-weight:880;line-height:1;letter-spacing:-.06em}.history-panel .element-meta{color:var(--muted);font-size:.76rem;margin-top:4px}.history-panel h2{font-size:.78rem;text-transform:uppercase;letter-spacing:.075em;color:var(--muted);margin:20px 0 8px}.history-panel p{font-size:.94rem;line-height:1.5;margin:7px 0}.history-tag{display:inline-flex;border:1px solid var(--line);border-radius:999px;padding:6px 9px;font-size:.71rem;margin:3px 3px 3px 0}.history-link{display:inline-flex;align-items:center;gap:5px;margin-top:16px;font-weight:750;text-decoration:none}.history-panel-status{margin-top:15px;padding:12px 13px;border-radius:13px;background:color-mix(in srgb,var(--surface-2,var(--surface)) 82%,transparent);border:1px solid var(--line);font-size:.82rem;line-height:1.45}.history-panel-status.pred{border-color:color-mix(in srgb,var(--history-gold) 70%,var(--line));background:color-mix(in srgb,var(--surface) 92%,var(--history-gold) 8%)}
.history-note{margin-top:14px;padding:14px 15px;border:1px solid var(--line);border-radius:15px;background:var(--surface-2,var(--surface));font-size:.84rem;line-height:1.55}.history-context{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:16px}.history-card{border:1px solid var(--line);background:var(--surface);border-radius:20px;padding:20px;box-shadow:0 10px 28px color-mix(in srgb,var(--text) 4%,transparent)}.history-card h2{font-size:1.08rem;margin:0 0 9px}.history-card p{margin:0;color:var(--muted);line-height:1.58}.history-pre{display:flex;flex-wrap:wrap;gap:7px;margin-top:13px}.history-pre span{border:1px solid var(--line);border-radius:999px;padding:6px 9px;font-size:.76rem}.history-predictions{display:grid;grid-template-columns:repeat(3,1fr);gap:9px;margin-top:13px}.history-prediction{position:relative;border:1px dashed var(--history-gold);border-radius:14px;padding:12px;background:color-mix(in srgb,var(--surface) 94%,var(--history-gold) 6%)}.history-prediction::before{content:"";position:absolute;inset-inline-start:-1px;top:11px;bottom:11px;width:3px;background:var(--history-gold);border-radius:4px}.history-prediction strong{display:block}.history-prediction small{color:var(--muted)}.history-layout-note{margin:13px 18px 18px;color:var(--muted);font-size:.75rem;line-height:1.5}.history-anchor{scroll-margin-top:18px}

.history-proof{--history-proof-progress:0%;position:relative;padding:14px 22px 18px;border-bottom:1px solid var(--line);background:linear-gradient(90deg,color-mix(in srgb,var(--surface) 96%,var(--history-gold) 4%),var(--surface))}.history-proof-head{display:flex;align-items:end;justify-content:space-between;gap:14px;margin-bottom:8px}.history-proof-head>div{display:flex;align-items:baseline;gap:10px;min-width:0}.history-proof-head strong{font-size:.86rem}.history-proof-head span,.history-proof-head small{color:var(--muted);font-size:.72rem;white-space:nowrap}.history-proof-steps{position:relative;display:grid;grid-template-columns:repeat(4,minmax(150px,1fr));gap:7px;min-width:690px}.history-proof-steps::before,.history-proof-steps::after{content:"";position:absolute;z-index:0;top:18px;inset-inline-start:8%;height:2px;border-radius:2px}.history-proof-steps::before{width:84%;background:color-mix(in srgb,var(--line) 82%,transparent)}.history-proof-steps::after{width:var(--history-proof-progress);max-width:84%;background:var(--history-gold);transition:width .28s cubic-bezier(.2,.8,.2,1)}.history-proof-step{position:relative;z-index:1;display:grid;grid-template-columns:auto 1fr;grid-template-areas:"dot year" "name name" "sub sub" "state state";column-gap:8px;align-items:center;border:1px solid transparent;border-radius:14px;background:transparent;color:var(--text);padding:7px 9px 9px;text-align:start;font:inherit;cursor:pointer;transition:background .18s,border-color .18s,transform .18s}.history-proof-step:hover{background:color-mix(in srgb,var(--surface) 86%,var(--history-gold) 14%);transform:translateY(-1px)}.history-proof-dot{grid-area:dot;width:10px;height:10px;border-radius:50%;background:var(--surface);border:2px solid var(--line);box-shadow:0 0 0 3px var(--surface);transition:background .18s,border-color .18s,box-shadow .18s}.history-proof-step>b{grid-area:year;font-size:.72rem;white-space:nowrap}.history-proof-step>strong{grid-area:name;margin-top:6px;font-size:.84rem;line-height:1.2}.history-proof-step>small{grid-area:sub;margin-top:3px;color:var(--muted);font-size:.68rem;line-height:1.25}.history-proof-state{grid-area:state;margin-top:7px;width:max-content;border:1px solid var(--line);border-radius:999px;padding:3px 6px;color:var(--muted);font-size:.62rem;line-height:1}.history-proof-step.is-past .history-proof-dot{background:var(--history-gold);border-color:var(--history-gold)}.history-proof-step.is-past .history-proof-state{border-color:color-mix(in srgb,var(--history-gold) 55%,var(--line));color:var(--text)}.history-proof.is-pred-mode{background:linear-gradient(90deg,color-mix(in srgb,var(--surface) 90%,var(--history-gold) 10%),var(--surface))}.history-proof-step.is-active{border-color:color-mix(in srgb,var(--history-gold) 72%,var(--line));background:color-mix(in srgb,var(--surface) 90%,var(--history-gold) 10%);box-shadow:0 8px 24px color-mix(in srgb,var(--history-gold) 12%,transparent)}.history-proof-step.is-active .history-proof-dot{background:var(--history-gold);border-color:var(--history-gold);box-shadow:0 0 0 4px color-mix(in srgb,var(--history-gold) 18%,var(--surface))}.hcell.story-target::before{position:absolute;z-index:4;top:4px;inset-inline-end:5px;display:grid;place-items:center;width:16px;height:16px;border-radius:50%;font-size:.65rem;font-weight:900;line-height:1}.hcell.predicted-gap::before{content:"?";color:var(--history-gold);border:1px solid color-mix(in srgb,var(--history-gold) 65%,var(--line));background:var(--surface)}.hcell.predicted-confirmed::before{content:"✓";color:var(--surface);background:var(--history-gold)}.hcell.story-current{box-shadow:0 0 0 3px color-mix(in srgb,var(--history-gold) 24%,transparent),0 10px 24px color-mix(in srgb,var(--history-gold) 18%,transparent);z-index:5}.hcell.story-current.predicted-gap{opacity:.86;filter:none}.hcell.story-current.predicted-confirmed{background:color-mix(in srgb,var(--surface) 72%,var(--history-gold) 28%)}
@media(max-width:1040px){.history-main{grid-template-columns:1fr}.history-table-wrap{border-inline-end:0;border-bottom:1px solid var(--line)}.history-panel{position:relative;top:auto;min-height:0}.history-toolbar{grid-template-columns:1fr}.history-modes{justify-content:flex-start}.history-context{grid-template-columns:1fr}}
@media(max-width:760px){.history-proof{padding-inline:14px;overflow:auto}.history-proof-head{position:sticky;inset-inline-start:0;width:max-content;min-width:100%;padding-inline-end:8px}.history-proof-head small{display:none}.history-proof-steps{min-width:660px}}
@media(max-width:660px){.history-shell{width:min(100% - 18px,1420px)}.history-stage{border-radius:18px}.history-toolbar{padding:18px 14px 14px;gap:14px}.history-year-row{grid-template-columns:40px 1fr 40px}.history-year-row>div{grid-template-columns:1fr;gap:8px}.history-year{font-size:3.25rem;grid-column:1/-1;min-width:0}.history-step{width:40px;height:40px}.history-now{padding:11px 14px;grid-template-columns:auto 1fr}.history-milestones{padding-inline:12px}.history-milestones button{min-width:108px}.history-stats{grid-template-columns:1fr 1fr}.history-stat{padding:13px 14px}.history-stat:nth-child(2){border-inline-end:0}.history-stat:last-child{grid-column:1/-1;border-top:1px solid var(--line)}.history-table-wrap{padding:12px}.history-predictions{grid-template-columns:1fr}.history-panel{padding:16px}.history-card{padding:16px}}
@media(prefers-reduced-motion:reduce){.hcell,.history-step,.history-modes button,.history-milestones button::before,.history-progress-bar,.history-proof-steps::after,.history-proof-step,.history-proof-dot{transition:none!important}.hcell.newly-visible{animation:none!important}}
.history-milestones{scroll-snap-type:x proximity}.history-milestones button{scroll-snap-align:center}.history-now-pill:focus-visible,.history-modes button:focus-visible,.history-step:focus-visible,.history-milestones button:focus-visible,.hcell:focus-visible{outline:2px solid var(--text);outline-offset:2px}

.history-proof-step:focus-visible{outline:2px solid var(--text);outline-offset:2px}
.history-print-card{margin-top:16px;display:flex;align-items:center;justify-content:space-between;gap:18px;padding:16px 18px;background:color-mix(in srgb,var(--surface) 97%,var(--history-blue) 3%)}
.history-print-copy{display:flex;align-items:baseline;gap:10px;min-width:0}.history-print-card h2{margin:0;font-size:.98rem}.history-print-meta{color:var(--muted);font-size:.72rem;white-space:nowrap;letter-spacing:.035em}.history-print-download{flex:0 0 auto;display:inline-flex;align-items:center;justify-content:center;min-height:38px;padding:8px 12px;border:1px solid var(--line);border-radius:11px;color:var(--text);background:var(--surface);text-decoration:none;font-size:.82rem;font-weight:760}.history-print-download:hover{border-color:color-mix(in srgb,var(--text) 35%,var(--line));transform:translateY(-1px)}.history-mendeleev-link{margin-top:11px!important}.history-mendeleev-link a{color:var(--text);font-weight:720;text-decoration:none}.history-mendeleev-link a:hover{text-decoration:underline;text-underline-offset:3px}
@media(max-width:560px){.history-print-card{align-items:flex-start}.history-print-copy{display:block}.history-print-meta{display:block;margin-top:4px}.history-print-download{min-height:36px;padding:7px 10px;font-size:.78rem}}

.history-bio-link{display:inline-block;margin-top:14px;font-size:.88rem;font-weight:700;text-decoration:none}.history-bio-link:hover{text-decoration:underline;text-underline-offset:3px}