:root{color-scheme:dark;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;background:#101213;color:#edf0ef;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;--muted: #a0aaa9;--line: #303636;--surface: #191c1d;--mint: #79dbbf}*{box-sizing:border-box;letter-spacing:0}body{margin:0;min-width:320px}button,input,select{font:inherit}button{color:inherit;cursor:pointer}button:disabled{opacity:.35;cursor:not-allowed}button,select,input{-webkit-tap-highlight-color:transparent}button:focus-visible,select:focus-visible,input:focus-visible,canvas:focus-visible,a:focus-visible{outline:2px solid var(--mint);outline-offset:3px}button{transition:background .15s,border-color .15s}button:hover:not(:disabled){border-color:var(--mint)}input[type=range],input[type=checkbox]{accent-color:var(--mint)}input[type=range]{min-width:60px;cursor:pointer}input[type=checkbox]{width:15px;height:15px;margin:0;cursor:pointer}a{color:var(--mint);text-underline-offset:3px}.app-shell{max-width:1840px;margin:0 auto;padding:0 24px 20px}.topbar{display:grid;grid-template-columns:minmax(250px,1fr) minmax(245px,.9fr) 180px auto;align-items:center;gap:12px;min-height:88px;border-bottom:1px solid var(--line)}.brand{display:flex;gap:12px;align-items:center}.brand>svg{color:var(--mint);flex-shrink:0}.brand strong{display:block;font-size:16px;font-weight:650}.brand span{display:block;color:var(--muted);font-size:12px;margin-top:4px}.search-wrap{position:relative;min-width:0;z-index:5}.search{display:flex;align-items:center;gap:9px;height:40px;padding:0 12px;border:1px solid var(--line);border-radius:5px;color:var(--muted);background:var(--surface)}.search:focus-within{border-color:var(--mint)}.search input{width:100%;min-width:0;border:0;outline:none;background:transparent;color:inherit;font-size:12px}.search input::placeholder{color:#919c9b}.search-results{position:absolute;top:45px;left:0;right:0;background:#222728;border:1px solid #586762;border-radius:5px;box-shadow:0 12px 30px #0008;overflow:hidden}.search-results button{display:flex;align-items:center;gap:12px;width:100%;padding:12px;border:0;background:transparent;text-align:left;font-size:13px}.search-results button:hover{background:#33423d}.search-results b{width:28px;color:var(--mint)}.search-results small{margin-left:auto;color:var(--muted)}.search-results p{padding:0 12px;font-size:13px}.topbar select,.random-button{height:40px;border:1px solid var(--line);border-radius:5px;background:var(--surface);color:#d8dfdc;font-size:12px}.topbar select{width:100%;padding:0 9px;text-transform:capitalize}.random-button{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:0 13px}.main-workspace{display:grid;grid-template-columns:minmax(0,1fr) 384px;min-height:760px;border-bottom:1px solid var(--line)}.model-panel{display:flex;min-width:0;flex-direction:column;background:#111516}.model-panel:fullscreen{padding:10px 24px;height:100%;width:100%}.model-toolbar{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px;padding:16px 16px 14px 0}.element-switcher{display:flex;align-items:center;gap:8px;flex:1;min-width:178px;max-width:225px}.element-switcher>div{flex:1;min-width:0}.element-switcher span{display:block;color:var(--muted);font-size:10px}.element-switcher strong{display:block;margin-top:3px;font-size:14px}.element-switcher>button,.icon-tools button,.plain-icon{display:grid;place-items:center;width:32px;height:34px;flex-shrink:0;padding:0;border:1px solid transparent;border-radius:4px;background:transparent;color:#bec8c5}.icon-tools{display:flex;gap:3px}.icon-tools button.active{color:var(--mint);background:#23362f}.segmented{display:inline-flex;padding:3px;border:1px solid var(--line);border-radius:5px;background:#0f1213}.segmented button{display:inline-flex;align-items:center;justify-content:center;gap:6px;height:31px;padding:0 9px;border:0;border-radius:3px;background:transparent;color:var(--muted);font-size:12px;font-weight:550}.segmented button.active{background:#35453f;color:#cefae8}.scene-controls{display:flex;flex-wrap:wrap;align-items:center;gap:16px;min-height:48px;padding:9px 16px;background:#191e1f;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.orbital-select,.range-control,.check-control{display:flex;align-items:center;gap:8px;color:#b4bfbc;font-size:12px}.orbital-select{flex:1}.orbital-select select{flex:1;width:140px;max-width:235px;min-width:100px;height:30px;padding:0 7px;border:1px solid #3d4845;border-radius:4px;background:#141819;color:#e1e8e5;font-size:12px}.range-control input{width:84px}.check-control{white-space:nowrap;cursor:pointer}.axes-control{margin-left:auto}.nucleus-caption{font-family:Consolas,monospace;font-size:13px;color:#eac695}.nucleus-caption span{margin-left:18px;color:var(--muted)}.viewer-stage{position:relative;flex:1;min-height:464px;overflow:hidden;background:#101516}.viewer-canvas{position:absolute;inset:0;cursor:grab}.viewer-canvas:active{cursor:grabbing}.viewer-canvas canvas{display:block;width:100%;height:100%;touch-action:none}.viewer-error{position:absolute;top:25%;left:12%;right:12%;z-index:2;padding:20px;border:1px solid #b78c52;background:#201f1b;color:#f2d9b8;line-height:1.6;font-size:14px}.scene-heading{position:absolute;top:23px;left:24px;pointer-events:none}.scene-heading>span{display:block;font-size:15px;font-weight:550;color:#d4dfda}.scene-heading small{display:block;font-size:12px;color:var(--muted);margin-top:6px}.scene-legend{position:absolute;left:24px;bottom:22px;display:flex;flex-wrap:wrap;gap:12px;max-width:calc(100% - 165px);pointer-events:none}.scene-legend span{display:inline-flex;align-items:center;gap:6px;font-size:11px;color:#b8c6c0}.scene-legend i,.legend-row i{width:7px;height:7px;border-radius:50%;flex-shrink:0}.proton-dot{background:#ef6155}.neutron-dot{background:#7da5dd}.electron-dot{background:#79dbbf}.camera-presets{position:absolute;right:20px;bottom:18px;display:flex;gap:5px}.camera-presets button{height:30px;padding:0 9px;border:1px solid #3a4542;border-radius:4px;background:#191f20;color:#becac5;font-size:11px}.orbital-readout{display:flex;flex-wrap:wrap;gap:8px 20px;padding:12px 18px;background:#191e1f;border-top:1px solid var(--line);color:#bcc6c3;font-size:12px}.orbital-readout b{color:#f0ca91}.orbital-readout small{color:var(--muted);font-size:11px;flex:1 1 100%}.model-footer{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px;padding:12px 16px;border-top:1px solid var(--line)}.shell-focus{display:flex;align-items:center;gap:5px;flex-wrap:wrap}.shell-focus>span{color:var(--muted);font-size:12px;margin-right:4px}.shell-focus button{height:30px;padding:0 8px;border:1px solid var(--line);border-radius:4px;background:#1b2221;color:#a9bab3;font-size:11px}.shell-focus button b{color:#dbe6df;margin-left:3px;font-weight:500}.shell-focus button.active{border-color:#79dbbf;background:#243f34;color:#a0edd5}.speed{gap:10px}.speed span{white-space:nowrap}.speed b{display:inline-block;min-width:26px;margin-left:5px;color:#d2dbd7;font-weight:500}.model-note{display:flex;align-items:flex-start;gap:7px;margin:0;padding:2px 16px 14px;font-size:11px;line-height:1.55;color:#8d9d96}.model-note svg{flex-shrink:0;margin-top:2px}.scale-note{font-size:12px;color:var(--muted)}.info-panel{min-width:0;padding:22px 20px 16px;border-left:1px solid var(--line);background:#171a1b;max-height:850px;overflow-y:auto;scrollbar-width:thin;scrollbar-color:#46534d transparent}.element-title{display:flex;align-items:center;gap:13px;min-width:0}.element-title>div:last-child{min-width:0}.large-symbol{display:flex;width:68px;height:78px;flex:0 0 auto;flex-direction:column;justify-content:space-between;padding:8px 10px;border-left:3px solid var(--accent);background:color-mix(in srgb,var(--accent) 10%,#191d1e)}.large-symbol small{color:var(--accent);font-size:12px}.large-symbol strong{color:#e9f2ed;font-size:32px;line-height:1.2}.category{color:var(--accent);font-size:11px;text-transform:capitalize}.element-title h1{margin:3px 0 0;font-size:26px;line-height:1.3;font-weight:600;overflow-wrap:anywhere}.element-title p{margin:4px 0 0;color:var(--muted);font-size:12px}.tabs{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));border-bottom:1px solid var(--line);margin-top:22px;gap:4px}.tabs button{height:38px;padding:0 2px;border:0;border-bottom:2px solid transparent;background:transparent;color:var(--muted);font-size:12px;text-transform:capitalize}.tabs button.active{color:#d3f7e6;border-color:var(--mint)}.tab-content{min-height:293px;padding:18px 0}.lead{font-size:13px;line-height:1.7;color:#bbc6c1;margin:0 0 18px}.fact-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px 18px;margin:0}.fact-grid dt{color:var(--muted);font-size:11px}.fact-grid dd{font-size:13px;margin:5px 0 0;color:#ebefe9;overflow-wrap:anywhere;line-height:1.4}.detail-section{margin:0}.detail-section+.detail-section{margin-top:20px}.detail-section h3,.property-heading h3{margin:0 0 6px;font-size:12px;font-weight:600;color:#e2e8e2}.detail-section p{margin:0;color:#b0bdb5;font-size:13px;line-height:1.65}.oxidation{margin-top:20px}.science-note{font-size:11px;line-height:1.6;color:#939f99;margin:16px 0 0}.configuration-block>span{display:block;color:var(--muted);font-size:12px}.configuration-formula{display:flex;flex-wrap:wrap;gap:6px 9px;margin:9px 0;font-family:Consolas,monospace;font-size:15px;line-height:1.4}.configuration-formula sup{font-size:10px}.configuration-block small{display:block;color:var(--muted);font-size:11px;line-height:1.6}.orbital-diagram{display:grid;gap:6px;margin-top:18px}.subshell-row{display:flex;align-items:center;gap:10px}.subshell-row>span{width:25px;font-family:Consolas,monospace;font-size:12px;color:#bcc6c0}.subshell-row>div{display:flex;gap:4px}.subshell-row button{display:flex;align-items:center;justify-content:center;width:32px;height:28px;padding:0;border:1px solid #45534b;border-radius:3px;background:#202b26;color:#a3dac0}.subshell-row button:disabled{background:transparent}.shell-list{display:grid;gap:8px;margin-top:20px}.shell-list>div{display:grid;grid-template-columns:106px 1fr 35px;gap:8px;align-items:center}.shell-list span,.shell-list b{font-size:11px;color:#b0bfb6}.shell-list small{color:#83948a}.shell-list>div>div{height:4px;background:#35423a}.shell-list i{display:block;height:100%;background:#80d5b0}.property-heading{display:flex;align-items:center;gap:10px;justify-content:space-between}.property-heading h3{margin:0;line-height:1.5}.property-heading .segmented button{height:26px;min-width:29px;padding:0 7px}.property-list{margin:13px 0 0}.property-list>div{display:flex;align-items:baseline;gap:12px;justify-content:space-between;padding:11px 0;border-bottom:1px solid #2b3430;font-size:12px}.property-list dt{color:#a9b8ae}.property-list dd{text-align:right;margin:0;color:#e1e7dd}.atom-builder{padding:17px 0 2px;border-top:1px solid var(--line)}.builder-heading{display:flex;align-items:center;justify-content:space-between;gap:10px}.builder-heading span{display:block;font-size:11px;color:var(--accent)}.builder-heading strong{display:block;font-size:13px;margin-top:5px;font-weight:500}.counter-row{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:12px}.counter-row>strong{font-size:12px;font-weight:500;color:#bec9c1}.stepper{display:grid;grid-template-columns:32px 40px 32px;align-items:center;height:32px;border:1px solid #3e4a42;border-radius:4px}.stepper button{display:grid;place-items:center;height:30px;padding:0;border:0;background:#212924;color:#a9bdb0}.stepper button:hover:not(:disabled){background:#354a3d}.stepper b{text-align:center;font-size:13px;font-weight:500;font-variant-numeric:tabular-nums}.particle-card{margin-top:16px;padding:12px;border:1px solid #637061;border-radius:4px;background:#262d25}.particle-card>div{display:flex;justify-content:space-between;gap:10px;font-size:13px}.particle-card span{color:#edbe8a}.particle-card p{margin:8px 0 0;color:#bbc6b7;font-size:12px;line-height:1.6}.source-link{display:flex;flex-wrap:wrap;gap:5px;align-items:center;margin-top:18px;font-size:11px;text-decoration:none}.source-link span{flex:1 1 100%;margin-top:3px;color:#88978d;font-size:10px}.periodic-panel{padding:24px 0 12px}.periodic-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:24px;margin-bottom:18px}.periodic-heading h2{flex-shrink:0;font-size:15px;margin:0;font-weight:550}.periodic-heading h2 span{display:block;margin-top:6px;font-size:11px;color:var(--muted);font-weight:400}.legend-row{max-width:810px;display:flex;flex-wrap:wrap;gap:7px 15px;justify-content:flex-end}.legend-row span{display:inline-flex;align-items:center;gap:5px;color:#a5b2a9;font-size:10px;text-transform:capitalize}.table-scroll{overflow-x:auto;padding:3px;scrollbar-width:thin;scrollbar-color:#506152 transparent}.periodic-grid{display:grid;grid-template-columns:repeat(18,minmax(50px,1fr));grid-template-rows:repeat(9,66px);gap:5px;min-width:1020px}.element-tile{position:relative;display:flex;min-width:0;flex-direction:column;align-items:flex-start;justify-content:center;padding:7px;border:1px solid color-mix(in srgb,var(--accent) 40%,#1a201d);border-radius:4px;background:color-mix(in srgb,var(--accent) 8%,#161b18);text-align:left;transition:opacity .15s,background .15s}.element-tile:hover{background:color-mix(in srgb,var(--accent) 25%,#161b18)}.element-tile.selected{border-color:var(--accent);outline:1px solid var(--accent);background:color-mix(in srgb,var(--accent) 24%,#161b18)}.element-tile.dimmed{opacity:.2}.element-tile strong{font-size:20px;line-height:1.15;margin-top:7px;font-weight:550}.tile-number{position:absolute;top:4px;right:5px;color:#a7b3aa;font-size:9px}.tile-name{width:100%;margin-top:4px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;color:#a8b4ac;font-size:9px}footer{display:flex;align-items:center;flex-wrap:wrap;justify-content:center;gap:6px;border-top:1px solid var(--line);padding-top:16px;margin-top:12px;color:#9da99f;font-size:11px;line-height:1.7}footer>span{margin:0 6px}@media(max-width:1200px){.topbar{grid-template-columns:1fr 1fr 165px auto}.brand strong{font-size:14px}.main-workspace{grid-template-columns:minmax(0,1fr) 340px}.info-panel{padding:22px 16px 16px}.model-toolbar{gap:8px}.model-toolbar>.segmented{order:3;width:100%}.model-toolbar>.segmented button{flex:1}.scene-controls{gap:12px}.orbital-select{flex-basis:100%}.orbital-select select{max-width:none}}@media(max-width:900px){.app-shell{padding:0 18px 20px}.topbar{grid-template-columns:minmax(0,1fr) 170px 42px;padding:16px 0}.brand{grid-column:1 / -1;margin-bottom:6px}.brand strong{font-size:16px}.random-button{padding:0}.random-button span{display:none}.main-workspace{grid-template-columns:1fr}.model-toolbar{padding-right:0}.model-toolbar>.segmented{order:0;width:auto}.scene-controls .orbital-select{flex-basis:auto}.viewer-stage{min-height:530px}.info-panel{border-left:0;border-top:1px solid var(--line);max-height:none;padding:24px}.tab-content{min-height:0}.fact-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.atom-builder{padding-bottom:8px}}@media(max-width:600px){.app-shell{padding:0 12px 18px}.topbar{grid-template-columns:minmax(0,1fr) 44px;gap:9px}.brand{margin-bottom:7px}.search-wrap{grid-column:1 / -1}.topbar select,.random-button{height:36px}.model-toolbar{padding:14px 0}.model-toolbar>.segmented{order:3;width:100%}.element-switcher{min-width:172px}.icon-tools{gap:0}.icon-tools button{width:29px}.scene-controls{padding:10px 12px;gap:12px}.scene-controls .orbital-select{flex-basis:100%}.range-control input{width:76px}.viewer-stage{min-height:440px}.scene-heading{top:20px;left:16px}.scene-heading>span{font-size:14px}.scene-heading small{font-size:11px}.scene-legend{left:16px;bottom:18px;gap:7px 10px;max-width:calc(100% - 132px)}.scene-legend span{font-size:10px}.camera-presets{right:12px;bottom:16px;gap:4px}.model-footer{padding:12px;gap:12px}.model-note{padding:2px 12px 16px}.info-panel{padding:22px 12px}.fact-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.element-title h1{font-size:25px}.periodic-heading{flex-direction:column;gap:16px}.legend-row{justify-content:flex-start;gap:7px 10px}.subshell-row>div{gap:3px}.subshell-row button{width:29px}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;transition-duration:.01ms!important}}