@font-face{font-family:"Plus Jakarta Sans";src:url(assets/PlusJakartaSans.ttf);font-weight:200 800;font-display:swap}:root{--ink:#142033;--blue:#0284c7;--muted:#64748b}*{box-sizing:border-box}html,body{margin:0;width:100%;height:100%;overflow:hidden;background:white;color:var(--ink);font-family:"Plus Jakarta Sans",Arial,sans-serif}button,input{font:inherit}button{cursor:pointer;border:0;background:transparent;color:var(--ink);border-radius:8px;padding:9px 12px}button:hover{background:#0284c719}button:focus-visible,input:focus-visible{outline:3px solid #0284c7;outline-offset:2px}.primary{background:#0284c7;color:white}.primary:hover{background:#0369a1}.layout,main,.viewer{width:100%;height:100%}.stage{width:100vw;height:100vh;position:relative;overflow:hidden;background:white}.stage svg,.stage>img{display:block;width:100%;height:100%;object-fit:contain}.stage text{font-family:"Plus Jakarta Sans",Arial,sans-serif}.controls{position:fixed;z-index:20;left:50%;bottom:16px;transform:translateX(-50%);display:flex;align-items:center;gap:4px;padding:7px;background:#ffffffdb;backdrop-filter:blur(18px);border:1px solid #dbe7ef88;border-radius:14px;box-shadow:0 4px 30px #14203313;opacity:0;transition:opacity .25s;white-space:nowrap;pointer-events:none}.controls.show,.controls:hover,.controls:focus-within{opacity:1;pointer-events:auto}.controls label{font-size:12px;display:flex;align-items:center;gap:8px}#scrub{width:110px;accent-color:#0284c7}#status{font-size:11px;color:#64748b;margin:0 8px}#runtime,#caption{display:none}.menu-hint{position:fixed;left:14px;top:14px;z-index:25;opacity:0;transition:opacity .25s;background:#ffffffb0;backdrop-filter:blur(12px)}.menu-hint:hover,.menu-hint.show,.menu-hint:focus-visible{opacity:1}.drawer{position:fixed;z-index:30;inset:0 auto 0 0;width:290px;padding:22px 14px;background:#ffffffed;backdrop-filter:blur(25px);overflow:auto;box-shadow:12px 0 45px #1420330d;transform:translateX(-110%);transition:transform .25s}.drawer.open{transform:translateX(0)}.drawer h1{font-size:18px;margin:6px 12px 18px}.drawer button.slide-link{display:block;width:100%;text-align:left;font-size:13px;line-height:1.5;margin-bottom:5px}.drawer button.active{background:#dff0fb;color:#0369a1}.drawer small{font-size:10px;color:#64748b}.notes{position:fixed;right:20px;top:20px;bottom:100px;z-index:26;max-width:550px;width:calc(100vw - 40px);overflow:auto;background:#fffffff2;backdrop-filter:blur(20px);padding:26px;box-shadow:0 5px 45px #14203317;line-height:1.75;border-radius:12px}.notes h2{font-size:18px;margin:0 0 12px}.notes p{white-space:pre-line;font-size:15px}.source{font-size:12px!important;color:#64748b}.math-sheet{position:absolute;inset:0;padding:5% 9%;background:white}.math-sheet h1{font-size:clamp(25px,3vw,46px)}.math-sheet h2{font-size:clamp(19px,2vw,31px);margin-top:4%}.math-sheet img{display:block;width:82%;max-width:90%;max-height:18%;object-fit:contain;margin:3% 0}.math-sheet p{font-size:clamp(17px,1.6vw,26px)}#welcome{position:fixed;bottom:95px;left:50%;transform:translateX(-50%);color:#64748b;font-size:13px;background:#ffffffdb;padding:8px 14px;border-radius:8px;transition:opacity .5s;pointer-events:none}.screen-reader{position:absolute;width:1px;height:1px;clip:rect(0,0,0,0);overflow:hidden}@media(max-width:800px){.controls{max-width:97vw;flex-wrap:wrap;justify-content:center;white-space:normal;bottom:10px}.controls button{font-size:12px;padding:8px}#status{display:none}#scrub{width:90px}.stage{height:100dvh}}@media print{.controls,.drawer,.notes,.menu-hint,#welcome{display:none}.stage{width:100vw;height:100vh}@page{size:landscape;margin:0}}
/* Immersive chapter rail: controls are only visible on hover or keyboard focus. */
.controls{bottom:74px;border:0;box-shadow:0 8px 38px #1420330b;background:#ffffffed;padding:5px 8px;border-radius:10px}
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