/* A quiet reader: the chapter is the canvas, the tools appear when needed. */
.visual-navigation{display:flex;flex-wrap:wrap;align-items:end;gap:9px;padding:12px 20px;background:var(--surface2);border-bottom:1px solid var(--border);flex-shrink:0}.visual-navigation label{display:flex;flex-direction:column;gap:4px;flex:1 1 140px;min-width:0;color:var(--muted);font-size:9px;letter-spacing:.6px}.visual-navigation select{width:100%;min-width:0;padding:8px 25px 8px 9px;font-size:12px;letter-spacing:0;background:var(--surface);color:var(--text);border:1px solid var(--border);border-radius:5px}.visual-navigation .visual-section-field{flex:1 1 calc(100% - 90px)}.visual-section-arrows{display:flex;gap:5px}.visual-section-arrows button{height:34px;width:34px;padding:0;background:var(--surface);color:var(--text);border:1px solid var(--border);border-radius:5px}.visual-section-arrows button:disabled{opacity:.35;cursor:default}.visual-navigation select:focus-visible,.visual-navigation button:focus-visible{outline:2px solid var(--accent);outline-offset:2px}@media(max-width:520px){.visual-navigation{padding:10px 16px;gap:7px}.visual-navigation label{flex-basis:120px}.visual-navigation select{font-size:11px}}
.reader-home{display:flex;align-items:center;gap:17px;min-width:0}.library-back{font-size:12px;color:var(--muted);white-space:nowrap}.library-back:hover{color:var(--accent)}.reader-home-divider{height:20px;border-left:1px solid var(--border)}
:root[data-theme=light]{--bg:#fff;--surface:#fff;--surface2:#f8f9fa;--surface3:#eff2f3;--text:#24292d;--muted:#626b72;--border:#e4e7e9;--accent:#16776c;--purple:#7752aa;--stage:#fff;--shadow:none}
html[data-theme=light] .visual-stage{background:#fff;background-image:none}
html[data-theme=light] .pdf-scroll{background:#fff}
.topbar{height:58px;padding:0 26px}.brand{font-size:22px}.brand .brand-mark{font-size:29px}.brand small,.course,.workspace-heading,.workspace-footer,.live-badge{display:none}
.header-actions>button#chapters-toggle{background:transparent;border:0;font-size:12px;padding:7px 10px}.app-shell{height:calc(100dvh - 58px);display:block;position:relative}.workspace{height:100%;padding:0}.study-grid{gap:0;grid-template-columns:minmax(0,1.05fr) minmax(0,1fr)}.panel{border:0;border-radius:0;box-shadow:none}.lecture-panel{border-right:1px solid var(--border)}.panel-toolbar{height:44px;padding:0 24px}.panel-title{font-size:10px;letter-spacing:.6px}.panel-title .tiny-icon{display:none}.pdf-scroll{padding:12px 24px}.pdf-page{box-shadow:none;margin-bottom:24px}.reader-footer{font-size:10px}.lab-scroll{padding:25px 34px 0}.lab-heading .eyebrow{font-size:9px;letter-spacing:.6px;color:var(--muted)}.lab-heading h2{font-family:Georgia,'Times New Roman',serif!important;font-size:29px;font-weight:400;line-height:1.2;letter-spacing:-.6px;margin:8px 0 10px}.lab-heading p{font-size:13px;line-height:1.7}.lab-tabs{display:none}.controls{margin-top:18px;margin-bottom:10px}.controls select{font-size:12px}.controls .atom-legend{flex-basis:100%;margin:0;padding:2px 0;font-size:10px}.atom-legend .legend-note{display:none}.visual-stage,.visual-stage.is-teaching{border:0;border-radius:0;height:340px;min-height:250px;background:var(--stage)}.stage-top{left:4px;right:4px}.stage-top>span{font-size:8px;letter-spacing:.5px}.stage-button{background:transparent;border:0;width:29px;height:29px}.scene-hint{font-size:10px}.teaching-readout{box-shadow:none;border:0;border-radius:0;background:var(--surface);font-size:15px}.metrics{border-top:1px solid var(--border);border-bottom:1px solid var(--border);gap:0;margin-top:0}.metric{background:transparent;border:0;border-radius:0;padding:12px}.metric+.metric{border-left:1px solid var(--border)}.metric strong{font-size:21px}.metric small{font-size:10px}.insight{background:transparent;border:0;padding:0;margin:18px 0;font-size:13px;line-height:1.8}.teaching-notes{background:transparent;border:0;padding:0;margin:18px 0}.teaching-notes p{font-size:13px}.teaching-notes h3{font-size:17px}.teaching-notes .formula{background:var(--surface2);border:0;font-size:17px}.teaching-toolbar{background:transparent;border:0;padding:10px 0;margin:0}.teaching-title>span{display:none}.teaching-title{justify-content:flex-start}.teach-choice select{font-size:12px}.teach-hint{font-size:11px}.component-grid span{background:var(--surface2)}#diagram-settings{margin:18px 0;padding:0;border:0;border-top:1px solid var(--border);border-radius:0}#diagram-settings>summary{font-size:12px;font-weight:400;padding:13px 0;color:var(--muted)}#extra-controls{padding-bottom:8px}.lab-bottom{margin-top:24px}.sidebar{position:fixed;left:0;top:58px;bottom:0;width:268px;z-index:60;background:var(--surface);box-shadow:8px 0 32px #0001;transform:translateX(-110%);transition:transform .18s;display:flex;padding:26px 18px 18px}.chapters-open .sidebar{transform:translateX(0)}.chapter-shade{position:fixed;inset:58px 0 0;z-index:59;background:#0003;border:0;border-radius:0;width:100%;height:calc(100dvh - 58px)}.sidebar .chapter-heading,.sidebar .search,.sidebar .toc-label,.sidebar .sidebar-bottom{display:block}.sidebar .search{display:flex}.sidebar .toc-label{display:flex}.sidebar #toc{display:block;overflow-y:auto;overflow-x:hidden;white-space:normal;scrollbar-width:thin}.sidebar #toc a{font-size:12px;padding:9px 8px;border-left:2px solid transparent;border-bottom:0}.sidebar #toc a.active{border-left-color:var(--accent)}
.learning-nav{margin:16px 0 10px;display:flex;align-items:center;justify-content:space-between;gap:10px;border-bottom:1px solid var(--border);padding-bottom:12px}.learning-nav label{font-size:12px;display:flex;align-items:center;gap:9px;color:var(--muted)}.learning-nav select{font-size:12px;border:0;background:var(--surface2);padding:8px 26px 8px 10px;max-width:100%}.review-count{font-size:10px;color:var(--muted);white-space:nowrap}.learning-activity{margin:16px 0 18px;border-left:2px solid var(--accent);padding:0 0 0 15px}.learning-activity:empty{display:none}.learning-activity h3{font-size:18px;line-height:1.4;font-family:Georgia,'Times New Roman',serif;font-weight:400;margin:6px 0 10px}.learning-activity p{font-size:13px;line-height:1.8;color:var(--muted);margin:8px 0}.learning-activity .eyebrow{font-size:9px;color:var(--accent)}.learning-activity .formula{font-size:17px;border:0;background:var(--surface2);padding:10px}.learning-activity button{background:var(--surface);font-size:12px;padding:8px 12px}.learning-activity button.primary{background:var(--accent);color:#fff;border-color:var(--accent)}.learning-activity .action-row{gap:7px}.learning-activity .quiz-options button{font-size:13px;padding:10px}.learning-activity .quiz-options button.correct{background:#16847310;border-color:var(--accent)}.learning-activity .quiz-options button.incorrect{background:#c8446b0b;border-color:#c8446b}.learning-activity .number-grid{margin:10px 0}.learning-activity .number-grid input{font-size:15px;background:var(--surface);padding:9px}.learning-activity .number-grid label{font-size:11px}.learning-feedback{font-size:13px;line-height:1.8;margin-top:12px}.learning-feedback:empty{display:none}.learning-feedback.success{color:var(--accent)}.learning-feedback.retry{color:var(--text)}.inspect-title{display:flex;justify-content:space-between;align-items:center;gap:10px}.inspect-title button{border:0;background:none;padding:0 5px;font-size:20px}.review-list{display:grid;gap:7px;margin:12px 0}.review-list button{text-align:left;line-height:1.6}.review-list small{display:block;color:var(--muted)}.guide-progress{height:2px;background:var(--border);margin:12px 0}.guide-progress span{height:100%;display:block;background:var(--accent)}.learning-activity .progress-note{font-size:11px}.learning-nav select:focus-visible{outline:2px solid var(--accent)}
#explore-view[data-predict-hidden=true]>#controls,#explore-view[data-predict-hidden=true]>#visual-stage,#explore-view[data-predict-hidden=true]>#metrics,#explore-view[data-predict-hidden=true]>#insight,#explore-view[data-predict-hidden=true]>#diagram-settings,#explore-view[data-predict-hidden=true]>#teaching-notes{display:none!important}
html[data-theme=dark] .learning-activity button.primary{color:#0c1220}
@media(min-width:1600px){.lab-scroll{padding:30px 50px 0}.visual-stage,.visual-stage.is-teaching{height:400px}.pdf-scroll{padding:12px 38px}}
@media(max-width:1100px){.lab-scroll{padding:21px 23px 0}.panel-toolbar{padding:0 17px}.pdf-scroll{padding:10px 13px}.lab-heading h2{font-size:25px}.visual-stage,.visual-stage.is-teaching{height:320px}}
@media(max-width:720px){.topbar{height:54px;padding:0 14px}.app-shell{height:calc(100dvh - 54px)}.sidebar{top:54px}.chapter-shade{top:54px;height:calc(100dvh - 54px)}.brand{font-size:21px}.workspace{padding:0;display:flex}.mobile-switch{display:flex;margin:0;border:0;border-bottom:1px solid var(--border);border-radius:0;padding:4px 12px;background:var(--surface);flex-shrink:0}.mobile-switch button{padding:7px;font-size:12px}.mobile-switch button.active{background:var(--surface2)}.study-grid{flex:1;display:flex}.lab-scroll{padding:22px 21px 0}.lab-heading h2{font-size:27px}.lab-heading p{font-size:13px}.panel-toolbar{height:38px;padding:0 17px}.learning-nav{flex-wrap:wrap}.learning-nav select{max-width:240px}.visual-stage,.visual-stage.is-teaching{height:320px}.metric strong{font-size:19px}.metric small{font-size:9px}.pdf-scroll{padding:10px}.teaching-readout{font-size:13px}.learning-activity{padding-left:12px}.sidebar .chapter-heading h1{font-size:30px}}
@media(max-width:520px){.reader-home{gap:11px}.reader-home .brand{font-size:18px}.reader-home .brand-mark{display:none}.reader-home .library-back{font-size:11px}.reader-home-divider{height:17px}.topbar{gap:8px}.header-actions{gap:5px}.header-actions>button#chapters-toggle{padding-left:4px;padding-right:4px}}
.lecture-lecturer{font-size:10px;color:var(--muted);margin:-4px 0 9px}.lecture-lecturer strong{font-weight:500;color:var(--accent)}
/* One compact chapter/section strip above the visualization. */
.visual-navigation{flex-wrap:nowrap;gap:8px;padding:12px 14px;background:#fffbea;border-bottom:1px solid #e7dfbf;align-items:center}.visual-navigation label{flex:1 1 0;gap:0;position:relative;font-size:0;letter-spacing:0}.visual-navigation label>select{height:36px;background:#fffdf5;border-color:#e7dfbf;font-size:11px}.visual-navigation .visual-section-field{flex:1.45 1 0}.visual-section-arrows{gap:3px}.visual-section-arrows button{width:26px;height:36px;background:#fffdf5;border-color:#e7dfbf}.lab-panel>.panel-toolbar{display:none}:root[data-theme=dark] .visual-navigation{background:var(--surface2);border-color:var(--border)}:root[data-theme=dark] .visual-navigation select,:root[data-theme=dark] .visual-section-arrows button{background:var(--surface);border-color:var(--border)}@media(max-width:720px){.visual-navigation{flex-wrap:wrap;padding:9px 12px}.visual-navigation label{flex:1 1 calc(50% - 8px)}.visual-navigation .visual-section-field{flex:1 1 calc(100% - 76px)}.visual-navigation select{font-size:12px}}