:root{color-scheme:light dark;--canvas:#f7f8f5;--paper:#fff;--ink:#20343e;--muted:#4d636b;--line:#ccd8d5;--tint:#eaf2ee;--teal:#145c60;--link:#175775;background:var(--canvas);color:var(--ink)}body{background:var(--canvas);color:var(--ink)}a{color:var(--link);text-underline-offset:3px}main.package{max-width:1120px;padding:30px 36px 24px}.package-header{display:flex;justify-content:space-between;align-items:center;gap:16px;padding-bottom:23px;border-bottom:1px solid var(--line)}.eyebrow,.step{color:var(--muted)}.edition{color:var(--muted);font-size:.78rem}.opening{padding:48px 0 35px}.kicker{font-size:.72rem;font-weight:750;letter-spacing:.14em;text-transform:uppercase;color:var(--teal);margin:0 0 8px}.opening h1{font-size:clamp(2.6rem,5.1vw,4.25rem);line-height:1.07;letter-spacing:-.045em;margin:12px 0 16px}.deck{font-size:1.25rem;color:var(--muted);margin-bottom:23px}.teach{max-width:810px;font-size:1.04rem;line-height:1.8}.teach p+p{margin-top:13px}.concept,#explore,.narration{border-top:1px solid var(--line);padding:28px 0 32px}.section-heading{display:flex;align-items:center;gap:15px}.number{display:grid;place-items:center;width:38px;height:38px;flex:none;border:1px solid var(--line);border-radius:50%;color:var(--teal);font-size:.78rem;font-weight:700}.section-heading h2{font-size:1.4rem;letter-spacing:-.025em;margin:0}.section-heading .kicker{margin:0 0 3px;font-size:.65rem}.concept figure{margin:24px 0 0;display:grid;grid-template-columns:minmax(0,1.6fr) minmax(0,1fr);align-items:center;gap:28px}.concept svg{display:block;width:100%;height:auto;border:1px solid var(--line);border-radius:18px}.concept figcaption{font-size:.96rem;color:var(--muted);line-height:1.75}.concept figcaption strong{display:block;color:var(--ink);font-size:1.08rem;margin-bottom:8px}.asset-note{font-size:.78rem;color:var(--muted);max-width:820px;margin-top:14px}.section-intro{max-width:770px;color:var(--muted);margin:14px 0 0}.layout{grid-template-columns:minmax(0,1fr) 310px;gap:18px;margin-top:22px}.viewer-card,.panel{background:var(--paper);border-color:var(--line)}.toolbar{background:var(--tint)}.instructions,.intro,.model-note,footer{color:var(--muted)}.panel .instructions{padding:0}.panel{padding:23px}.panel h2{font-size:1.2rem;margin-top:10px}.step{font-size:.68rem}.principle{background:var(--tint)}.guide{margin-top:27px}.guide h2{font-size:1.05rem;margin-bottom:10px}.guide article{padding:14px 0;border-color:var(--line)}.guide article h3{font-size:.95rem}.guide article p{font-size:.88rem;max-width:850px}.guide>p{font-size:.8rem;color:var(--muted)}.callout a,.panel a,.guide a{color:var(--link);overflow-wrap:anywhere}.scene{height:395px}.narration{padding-bottom:28px}.narration>p{margin-left:53px}.package-footer{display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;border-top:1px solid var(--line);padding-top:22px;margin-top:0;font-size:.72rem}.package-footer p{flex-basis:100%;margin:0}.skip{position:absolute;top:-80px;left:16px;padding:12px;background:var(--paper);z-index:10}.skip:focus{top:10px}button{max-width:100%}#sensor-viewer{min-width:0}html{scroll-behavior:auto}
@media(max-width:800px){main.package{padding:22px 20px}.edition{display:none}.opening{padding-top:33px}.teach{font-size:.96rem;line-height:1.75}.deck{font-size:1.08rem}.concept figure{grid-template-columns:1fr;gap:14px}.section-heading h2{font-size:1.17rem}.layout{grid-template-columns:1fr}.scene{height:330px}.concept,#explore,.narration{padding-top:24px}.narration>p{margin-left:0}.package-footer{display:block}.package-footer span{display:block;margin-bottom:8px}}
@media(prefers-color-scheme:dark){:root{--canvas:#14232a;--paper:#1d3038;--ink:#e2ecee;--muted:#b5c9ce;--line:#456069;--tint:#263f45;--teal:#89d6cc;--link:#9bcdec}button{background:#263e47;color:var(--ink);border-color:#829aa1}button:hover{background:#33505b}button[aria-pressed=true]{background:#a5dcd4;color:#142e33;border-color:#a5dcd4}.scene{border-block:1px solid var(--line)}:focus-visible{outline-color:#ffbc76}.concept svg{color-scheme:light}}

.narration audio{display:block;max-width:100%;margin:20px 0 16px}.narration-transcript{max-width:850px}.narration-transcript summary{cursor:pointer;color:var(--link)}.transcript-text{white-space:pre-wrap;overflow-wrap:anywhere;line-height:1.8;margin-top:14px}