/* Scope every rule to this optional atlas; exam figures and app state are untouched. */
.bio-structure-atlas { color:var(--text,#293e36); font-family:var(--body-font,-apple-system,BlinkMacSystemFont,"PingFang HK","Noto Sans TC",sans-serif); padding:24px 0 44px; }
.bio-structure-atlas [hidden] { display:none!important; }
.bio-structure-atlas .sa-heading { border:0; border-radius:0; padding:0; background:none; box-shadow:none; }
.bio-structure-atlas .sa-kicker { font:11px/1.5 ui-monospace,SFMono-Regular,Menlo,monospace; letter-spacing:.12em; color:var(--muted,#58675b); margin:0 0 6px; }
.bio-structure-atlas .sa-heading h2 { margin:0 0 8px; font-size:28px; }
.bio-structure-atlas .sa-intro { margin:0; max-width:850px; color:var(--muted,#58675b); }
.bio-structure-atlas .sa-topics { display:grid; grid-template-columns:repeat(5,minmax(0,1fr)); gap:12px; margin:22px 0 28px; }
.bio-structure-atlas button { border-radius:0; font:inherit; touch-action:manipulation; cursor:pointer; }
.bio-structure-atlas .sa-topic { display:flex; flex-direction:column; padding:0; border:1px solid var(--line,#c3cbbb); background:var(--surface,#fffdf6); color:var(--ink,#163b32); text-align:left; overflow:hidden; }
.bio-structure-atlas .sa-topic[aria-pressed="true"] { border:2px solid var(--ink,#163b32); box-shadow:3px 3px 0 var(--moss,#66846a); }
.bio-structure-atlas .sa-topic-art { width:100%; height:auto; aspect-ratio:3/2; object-fit:contain; image-rendering:pixelated; background:var(--paper,#f5f2e8); }
.bio-structure-atlas .sa-topic-copy { display:block; padding:10px 12px; }
.bio-structure-atlas .sa-topic-copy strong { display:block; font-size:15px; }
.bio-structure-atlas .sa-topic-copy small { display:block; font-size:12px; color:var(--muted,#58675b); margin-top:3px; }
.bio-structure-atlas .sa-study { border:1px solid var(--line,#c3cbbb); background:var(--surface,#fffdf6); padding:22px; }
.bio-structure-atlas .sa-study-title { font-size:23px; margin:0 0 8px; }
.bio-structure-atlas .sa-study-intro { margin:0 0 16px; max-width:940px; }
.bio-structure-atlas .sa-study-row { display:grid; grid-template-columns:minmax(0,1.35fr) minmax(300px,1fr); gap:24px; align-items:start; }
.bio-structure-atlas .sa-figure { margin:0; min-width:0; }
.bio-structure-atlas .sa-canvas { border:1px solid var(--line,#c3cbbb); background:var(--paper,#f5f2e8); overflow:hidden; }
.bio-structure-atlas .sa-visual { display:block; width:100%; height:auto; aspect-ratio:3/2; image-rendering:pixelated; }
.bio-structure-atlas .sa-base-image,.bio-structure-atlas .sa-selected-image { image-rendering:pixelated; }
.bio-structure-atlas .sa-base-image { opacity:1; filter:none; }
.bio-structure-atlas .sa-visual.has-selection .sa-base-image { opacity:.36; filter:blur(1.4px); }
.bio-structure-atlas .sa-selected-image { opacity:1; filter:none; }
.bio-structure-atlas .sa-selected-layer { pointer-events:none; }
.bio-structure-atlas .sa-outline-under,.bio-structure-atlas .sa-outline { fill:none; stroke-linejoin:miter; stroke-linecap:square; vector-effect:non-scaling-stroke; shape-rendering:crispEdges; }
.bio-structure-atlas .sa-outline-under { stroke:#163b32; stroke-width:5px; }
.bio-structure-atlas .sa-outline { stroke:#f6cf69; stroke-width:2px; }
.bio-structure-atlas .sa-hotspot { fill:transparent; stroke:transparent; stroke-width:1px; pointer-events:fill; cursor:pointer; outline:none; }
.bio-structure-atlas .sa-hotspot:focus-visible { stroke:var(--ink,#163b32); stroke-width:3px; vector-effect:non-scaling-stroke; stroke-dasharray:7 3; outline:none; }
.bio-structure-atlas .sa-controls { display:flex; gap:8px; flex-wrap:wrap; padding:12px 0 8px; }
.bio-structure-atlas .sa-control,.bio-structure-atlas .sa-chapter-link { min-height:44px; border:1px solid var(--ink,#163b32); color:var(--ink,#163b32); background:var(--paper,#f5f2e8); padding:8px 12px; font-size:13px; }
.bio-structure-atlas .sa-control:hover:not(:disabled),.bio-structure-atlas .sa-chapter-link:hover { background:var(--sage,#e5ead9); }
.bio-structure-atlas button:disabled { opacity:.45; cursor:not-allowed; }
.bio-structure-atlas .sa-caption { font-size:12px; line-height:1.6; color:var(--muted,#58675b); }
.bio-structure-atlas .sa-instruction { margin:0 0 10px; font-size:14px; font-weight:650; color:var(--ink,#163b32); }
.bio-structure-atlas .sa-part-list { display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); gap:7px; margin-bottom:18px; }
.bio-structure-atlas .sa-part { position:relative; display:flex; flex-wrap:wrap; gap:2px 4px; align-items:center; min-height:48px; padding:8px 8px 8px 26px; border:1px solid var(--line,#c3cbbb); background:var(--paper,#f5f2e8); text-align:left; color:var(--ink,#163b32); }
.bio-structure-atlas .sa-part strong { font-size:13px; line-height:1.5; }
.bio-structure-atlas .sa-part small { display:block; width:100%; font-size:10px; line-height:1.5; color:var(--muted,#58675b); overflow-wrap:anywhere; }
.bio-structure-atlas .sa-part-check { position:absolute; left:8px; top:11px; width:14px; height:14px; image-rendering:pixelated; }
.bio-structure-atlas .sa-part.is-selected { border:2px solid var(--ink,#163b32); background:#e5ead9; padding:7px 7px 7px 25px; }
.bio-structure-atlas .sa-explanation { border-top:3px solid var(--ink,#163b32); padding:14px 0 0; min-height:180px; margin-bottom:18px; }
.bio-structure-atlas .sa-explanation h4 { margin:0; font-size:22px; color:var(--ink,#163b32); }
.bio-structure-atlas .sa-explanation p { font-size:14px; margin:8px 0; line-height:1.75; }
.bio-structure-atlas .sa-explanation .sa-selected-kicker { color:var(--muted,#58675b); font-size:12px; margin-top:0; }
.bio-structure-atlas .sa-explanation .sa-english { font-size:12px; color:var(--muted,#58675b); margin:4px 0 12px; }
.bio-structure-atlas .sa-function { font-weight:650; }
.bio-structure-atlas .sa-explanation .sa-selection-note { font-size:12px; color:var(--muted,#58675b); }
.bio-structure-atlas .sa-chapter-links { display:flex; gap:7px; flex-wrap:wrap; margin:12px 0; }
.bio-structure-atlas .sa-part-sources { border-top:1px solid var(--line,#c3cbbb); padding-top:10px; font-size:11px; line-height:1.6; }
.bio-structure-atlas .sa-part-sources strong { display:block; margin-bottom:4px; color:var(--muted,#58675b); }
.bio-structure-atlas .sa-part-sources a { display:block; color:#345e53; margin:4px 0; text-underline-offset:3px; overflow-wrap:anywhere; }
.bio-structure-atlas .sa-terminology,.bio-structure-atlas .sa-source-note { font-size:12px; line-height:1.7; color:var(--muted,#58675b); margin:14px 0 0; }
.bio-structure-atlas .sa-view-tabs { display:flex; gap:7px; flex-wrap:wrap; margin:0 0 14px; }
.bio-structure-atlas .sa-view-tab { border:1px solid var(--line,#c3cbbb); padding:8px 10px; min-height:44px; background:var(--paper,#f5f2e8); color:var(--ink,#163b32); font-size:13px; }
.bio-structure-atlas .sa-view-tab[aria-pressed="true"] { border-color:var(--ink,#163b32); background:var(--ink,#163b32); color:var(--surface,#fffdf6); }
.bio-structure-atlas .sa-live { position:absolute; width:1px; height:1px; padding:0; margin:-1px; overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; border:0; }
.bio-structure-atlas button:focus-visible,.bio-structure-atlas a:focus-visible { outline:3px solid var(--focus,#936d24); outline-offset:3px; }
@media(max-width:1000px) { .bio-structure-atlas .sa-topics { grid-template-columns:repeat(3,minmax(0,1fr)); } .bio-structure-atlas .sa-study-row { grid-template-columns:minmax(0,1fr) minmax(270px,.9fr); gap:18px; } }
@media(max-width:760px) { .bio-structure-atlas .sa-study-row { display:flex; flex-direction:column; gap:18px; } .bio-structure-atlas .sa-figure,.bio-structure-atlas .sa-aside { width:100%; } .bio-structure-atlas .sa-study { padding:16px; } .bio-structure-atlas .sa-topics { grid-template-columns:repeat(2,minmax(0,1fr)); gap:10px; } .bio-structure-atlas .sa-heading h2 { font-size:24px; } .bio-structure-atlas .sa-intro { font-size:14px; } .bio-structure-atlas .sa-controls { flex-wrap:nowrap; } .bio-structure-atlas .sa-control { flex:1; padding:7px 8px; font-size:12px; } .bio-structure-atlas .sa-topic-copy { padding:8px; } .bio-structure-atlas .sa-topic-copy strong { font-size:13px; } .bio-structure-atlas .sa-topic-copy small { font-size:11px; } }
@media(prefers-reduced-motion:reduce) { .bio-structure-atlas * { animation:none!important; transition:none!important; scroll-behavior:auto!important; } }