:root{color-scheme:light;--ink:#263f4b;--muted:#5e707a;--line:#dce4e6;--teal:#176e70;--pale:#eef6f5;--gold:#b29a69;--purple:#715e99}
*{box-sizing:border-box}body{margin:0;background:#fff;color:var(--ink);font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.6}main{max-width:1250px;margin:auto;padding:32px 28px 24px}h1,h2,p,figure{margin:0}h1{font-family:Georgia,serif;font-size:clamp(1.8rem,3.7vw,2.8rem);font-weight:400;line-height:1.2;letter-spacing:-.03em;margin:10px 0 14px}h2{font-family:Georgia,serif;font-size:clamp(1.5rem,2.5vw,2rem);font-weight:400;line-height:1.25;letter-spacing:-.015em;margin:8px 0 16px}.eyebrow{text-transform:uppercase;letter-spacing:.13em;font-size:.7rem;font-weight:650;color:var(--teal)}.lead{max-width:850px;font-size:1.05rem;color:var(--muted)}button,input,summary{font:inherit}button,summary{cursor:pointer}button:focus-visible,input:focus-visible,summary:focus-visible,a:focus-visible{outline:3px solid #629ba9;outline-offset:4px}button{transition:background-color .15s,color .15s}button:disabled{opacity:.35;cursor:default}
.dimensions{list-style:none;display:grid;grid-template-columns:repeat(4,1fr);gap:0;padding:0;margin:25px 0 20px;border:1px solid var(--line);border-radius:10px;overflow:hidden}.dimensions li{font-size:.86rem;padding:12px 14px;border-right:1px solid var(--line)}.dimensions li:last-child{border-right:0}.dimensions li span{color:#819398;font-size:.7rem;margin-right:8px}.dimensions li[aria-current="step"]{background:var(--pale);color:#115a5d;font-weight:650}.dimensions li[aria-current="step"] span{color:var(--teal)}
.toolbar{display:flex;align-items:center;gap:8px;padding:0 0 20px}.icon-button,.play-button{height:44px;border:1px solid var(--line);border-radius:8px;background:white;min-width:44px;color:var(--ink)}.play-button{background:var(--ink);color:white;min-width:103px;padding:0 12px}.play-button:hover{background:var(--teal)}.icon-button:hover{background:var(--pale)}#play-icon{font-size:.85rem;margin-right:4px}.timeline{flex:1;min-width:120px;padding:0 18px}.timeline label{display:flex;justify-content:space-between;font-size:.76rem;color:var(--muted)}#progress{width:100%;accent-color:var(--teal);cursor:pointer;height:18px;margin:5px 0 0;display:block}.options{display:flex;gap:12px;font-size:.78rem;color:var(--muted)}.options label{display:flex;align-items:center;gap:4px;white-space:nowrap}.options input{accent-color:var(--teal);width:15px;height:15px}
.stage-nav{display:grid;grid-template-columns:repeat(4,1fr);gap:7px;margin:0 0 24px}.stage-nav button{display:flex;align-items:center;gap:8px;border:1px solid var(--line);border-radius:7px;background:#fff;color:var(--muted);text-align:left;padding:10px;font-size:.8rem;line-height:1.3;min-height:46px}.stage-nav button span{display:inline-flex;align-items:center;justify-content:center;border:1px solid var(--line);border-radius:50%;height:23px;width:23px;flex-shrink:0;font-size:.74rem}.stage-nav button[aria-pressed="true"]{color:#fff;background:var(--teal);border-color:var(--teal)}.stage-nav button[aria-pressed="true"] span{border-color:#ffffff65}.stage-nav button:hover:not([aria-pressed="true"]){background:var(--pale)}
.visual-grid{display:grid;grid-template-columns:minmax(0,1.5fr) minmax(260px,1fr);border:1px solid var(--line);border-radius:12px;overflow:hidden;align-items:start}.main-view{padding:17px 18px 16px;position:sticky;top:0}.main-view svg{display:block;width:100%;height:auto}.view-label{display:flex;justify-content:space-between;gap:12px;color:var(--muted);font-size:.68rem;text-transform:uppercase;letter-spacing:.1em}.view-label span:last-child{color:#859197}.main-view figcaption{max-width:520px;font-size:.76rem;color:var(--muted);line-height:1.5;padding:5px 10px 0}.explanation{padding:25px 25px 20px;background:#f8faf9;border-left:1px solid var(--line);align-self:stretch}.explanation>p:not(.eyebrow):not(.legend){font-size:.94rem;line-height:1.6}#stage-text{min-height:124px}.takeaway{padding:12px 0 12px 13px;border-left:3px solid var(--gold);margin:18px 0;color:#415b65}.anatomy-key{list-style:none;counter-reset:key;padding:0;margin:17px 0;font-size:.79rem;color:var(--muted);display:grid;gap:9px}.anatomy-key li{counter-increment:key;display:flex;gap:8px;align-items:flex-start;line-height:1.45}.anatomy-key li:before{content:counter(key);display:inline-flex;justify-content:center;align-items:center;width:21px;height:21px;flex-shrink:0;border:1px solid #406574;border-radius:50%;background:white;color:#284b5a;font-size:.72rem}.anatomy-key[hidden]{display:none}.detail-view{border:1px solid var(--line);border-radius:8px;overflow:hidden;background:white;margin-top:18px}.detail-view figcaption{font-size:.75rem;color:var(--muted);padding:8px 12px;border-bottom:1px solid var(--line)}.detail-view svg{display:block;width:100%;max-height:290px;margin:auto}.legend{display:flex;flex-wrap:wrap;gap:5px 13px;margin-top:12px;font-size:.64rem;color:var(--muted)}.legend span:before{content:"";display:inline-block;width:10px;height:3px;margin-right:5px;vertical-align:middle;background:var(--teal)}.legend .purple:before{background:var(--purple)}.legend .gold:before{background:var(--gold)}
.technical{border-bottom:1px solid var(--line);margin:8px 0 14px;padding:12px 2px;font-size:.84rem}.technical summary{font-weight:600}.technical p{margin-top:12px;max-width:950px;color:var(--muted)}footer{font-size:.71rem;color:var(--muted);line-height:1.6}footer>p{max-width:1000px}.sources{margin-top:8px}.sources p{margin-top:8px;max-width:1050px}a{color:#176d7c;text-underline-offset:3px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
@media(min-width:1450px){main{padding-top:38px}.detail-view svg{max-height:310px}}
@media(max-width:760px){main{padding:22px 16px 18px}.dimensions li{padding:10px 8px;font-size:.75rem}.dimensions li span{display:block;font-size:.65rem}.toolbar{flex-wrap:wrap}.timeline{padding:0 2px 0 8px}.options{width:100%;justify-content:flex-end;margin-top:3px}.stage-nav{grid-template-columns:repeat(2,1fr);gap:6px;margin-bottom:17px}.visual-grid{grid-template-columns:1fr}.main-view{position:static;padding:13px 12px}.main-view svg{max-height:650px}.explanation{border-left:0;border-top:1px solid var(--line);padding:23px 20px}#stage-text{min-height:0}.detail-view{max-width:410px;margin:20px auto 0}.detail-view svg{max-height:290px}.lead{font-size:.94rem}.view-label{font-size:.6rem}.legend{justify-content:center}h2{font-size:1.7rem}}
@media(prefers-reduced-motion:reduce){button{transition:none}}