:root{--ink:#22231f;--paper:#fdf9ef;--muted:#5d6158;--pink:#f04686;--pink-soft:#ffebf1;--lime:#c5e974;--line:#d9d8cb;--blue:#2e63c8;--display:'Bricolage Grotesque',system-ui,sans-serif;--mono:'Space Mono',monospace}
*{box-sizing:border-box}[hidden]{display:none!important}
body{margin:0;background:var(--paper);color:var(--ink);font:500 17px/1.65 var(--display);-webkit-font-smoothing:antialiased}
h1,h2,h3,p{margin-top:0}h1,h2{letter-spacing:-.04em;line-height:1.15}h1{font-size:clamp(30px,3.2vw,46px);margin-bottom:0}h2{font-size:clamp(27px,2.5vw,35px);margin-bottom:24px}h3{font-size:15px;line-height:1.4;margin-bottom:8px}p{margin-bottom:20px}
button,select{font:600 15px/1.4 var(--display);color:inherit;min-height:44px;touch-action:manipulation}button{cursor:pointer}button:disabled{cursor:default}a{color:inherit;text-underline-offset:4px}a,button,summary{-webkit-tap-highlight-color:transparent}button:focus-visible,a:focus-visible,summary:focus-visible,select:focus-visible,canvas:focus-visible{outline:3px solid var(--blue);outline-offset:4px}
button:disabled:not(.correct):not(.incorrect){opacity:.6}button:hover:not(:disabled){filter:brightness(.97)}.primary{padding:14px 25px;border:2px solid var(--ink);border-radius:13px;background:var(--ink);color:var(--paper);font-size:16px;box-shadow:3px 3px 0 var(--pink)}.secondary{padding:9px 15px;border:1px solid #aeb4a9;border-radius:9px;background:var(--paper);font-size:13px}.secondary[aria-pressed=true]{background:var(--pink-soft);border-color:var(--pink)}.text-button{border:0;background:transparent;padding:12px 0;text-decoration:underline;text-underline-offset:5px;font-size:14px;color:var(--muted)}
.masthead{max-width:1300px;margin:auto;display:flex;align-items:center;justify-content:space-between;padding:20px 32px;border-bottom:1px solid var(--line)}.brand{font-size:34px;font-weight:800;letter-spacing:-2px;line-height:1;text-decoration:none;display:inline-flex;align-items:center;min-height:44px}.brand span{color:var(--pink);padding-left:3px}.masthead nav a{font-size:13px;min-height:44px;display:flex;align-items:center}
#classroom{max-width:1300px;padding:0 32px 24px;margin:auto}.lesson-heading{padding:32px 0 30px}.eyebrow,.kicker{font:11px/1.6 var(--mono);letter-spacing:.06em;color:var(--muted);margin-bottom:12px;scroll-margin-top:20px}.kicker{color:#795344}.workspace{display:grid;grid-template-columns:minmax(320px,.85fr) minmax(0,1.15fr);gap:48px;align-items:start}.workspace.text-only{display:block;max-width:760px;margin:0 auto}.step-card{min-width:0;padding:12px 0 0}.step-card:focus{outline:none}.objectives{padding-left:22px;margin:24px 0}.objectives li{padding-left:7px;margin:11px 0}.objectives li::marker{color:var(--pink)}.quiet-copy{font-size:14px;color:var(--muted);line-height:1.6}.look-note{border-left:3px solid var(--pink);padding:12px 18px;background:var(--pink-soft);font-size:14px;line-height:1.6;margin-top:25px;border-radius:0 10px 10px 0}
.model-card{border:1px solid #b6bbaf;border-radius:20px;background:#f4f1e7;overflow:hidden;position:sticky;top:24px}.model-heading{display:flex;align-items:center;gap:9px;padding:15px 20px;border-bottom:1px solid #d9ddcf;font-size:13px;background:#f7f5ec}.color-dot{width:9px;height:9px;border-radius:50%;background:var(--pink);flex:none}.model-label{margin-left:auto;font:11px var(--mono);color:var(--muted)}.sl-viewer{height:400px;position:relative;isolation:isolate;background:radial-gradient(ellipse at center,#fffdf7,#f0eee3);overflow:hidden}.sl-viewer canvas{position:absolute;inset:0;display:block;width:100%;height:100%;touch-action:none}.sl-labels{position:absolute;inset:0;pointer-events:none;overflow:hidden}.sl-labels span{position:absolute;transform:translate(-50%,-50%);background:var(--paper);border:1px solid #51554b;border-radius:50%;padding:2px 6px;font:11px var(--mono)}#model-status{position:absolute;z-index:4;margin:14px;padding:12px 15px;background:var(--paper);border-radius:10px;font-size:14px;pointer-events:none}#model-controls{padding:12px 16px 0}.tools{display:flex;gap:8px;flex-wrap:wrap}.tools button{flex:1}.gesture{font-size:11px;color:var(--muted);padding:10px 16px 14px;margin:0}.model-caption{font-size:13px;margin:10px 0 2px}.picker{display:grid;gap:8px;font-size:13px;margin-bottom:10px}.picker select{max-width:100%;width:100%;border:1px solid var(--line);border-radius:8px;padding:10px;background:var(--paper)}
.options{display:grid;gap:12px;margin:24px 0 4px}.options button{display:flex;gap:12px;text-align:left;align-items:center;width:100%;padding:17px 18px;border:1.5px solid #b6bbaf;border-radius:13px;background:#fffdf8;font-size:16px;line-height:1.5}.letter{flex:none;width:26px;height:26px;display:grid;place-items:center;border:1px solid #91988b;border-radius:7px;font:12px var(--mono)}.options button[aria-pressed=true]{border:2px solid var(--ink);background:#f2e8eb}.options button:disabled{opacity:1!important}.options button.correct{background:#edf6dc;border-color:#6b8d40}.options button.incorrect{background:#fff0e7;border-color:#b47751}.answer-mark{font-size:11px;margin-left:auto;color:#37591c;flex:none}.feedback{border:1px solid #d5b9a2;border-radius:13px;padding:20px;background:#fff0e5;margin:24px 0 10px}.feedback.success{background:#eef5e1;border-color:#b1c69b}.feedback h3{font-size:19px;margin-bottom:12px}.feedback p{margin:0 0 12px;font-size:15px}.feedback p:last-child{margin:0}.pick-status{border-bottom:2px solid var(--pink);padding-bottom:16px;font-size:15px}.review-note{padding:20px 22px;background:#edf4dd;border-radius:13px;margin:25px 0}.review-note ul{margin-bottom:0}.review-note li{margin:5px 0}.notebook-note{border-block:1px solid var(--line);padding:10px 0;margin:24px 0}.notebook-note summary{font-size:15px;padding:8px 0;cursor:pointer}.notebook-note p{font-size:15px;padding-top:10px}.notebook-note details{margin:0 12px}
#step-footer{position:sticky;bottom:0;display:flex;align-items:center;justify-content:space-between;gap:24px;padding:20px 0 max(20px,env(safe-area-inset-bottom));margin-top:32px;border-top:1px solid var(--line);background:var(--paper);z-index:4}.autosave{font-size:11px;color:var(--muted)}#step-footer .primary{min-width:240px}.explore-entry{margin-top:15px}#exit-explore{padding-top:24px}.credits{font-size:11px;color:var(--muted);margin-top:16px}.credits summary{cursor:pointer;min-height:32px}.credits p{margin-bottom:5px}#save-warning{background:#fff0e5;padding:14px;border-left:3px solid #a6522f;font-size:14px}.keyboard-pick{margin-top:10px;font-size:12px}.keyboard-pick summary{cursor:pointer;min-height:36px;padding:8px 0}.number-pieces{display:grid;grid-template-columns:repeat(6,1fr);gap:6px}.number-pieces button{background:var(--paper);border:1px solid #a5ad9c;border-radius:7px;font-size:12px}.number-pieces button[aria-pressed=true]{background:var(--pink-soft)}
#bone-overlay{position:absolute;inset:8px;z-index:5;background:var(--paper);border:1px solid var(--ink);border-radius:16px;padding:24px;overflow:auto;overscroll-behavior:contain;touch-action:pan-y}#bone-overlay h2{font-size:28px;padding-right:24px;margin-bottom:18px}#bone-overlay p{font-size:14px;margin-bottom:18px}#bone-overlay .kicker{font-size:10px;padding-right:32px}#bone-overlay .close{position:absolute;top:10px;right:10px;border:1px solid #929a89;background:var(--paper);width:44px;height:44px;font-size:26px;border-radius:50%}
#study-panel{min-width:0;width:100%}#study-panel>#bone-overlay{position:relative;inset:auto;z-index:auto;border:0;border-radius:0;padding:12px 0 0;overflow:visible;touch-action:auto}#study-panel>#bone-overlay h2{font-size:clamp(27px,2.5vw,35px);padding-right:54px;line-height:1.15}#study-panel>#bone-overlay p{font-size:16px}#study-panel>#bone-overlay .kicker{font-size:11px;padding-right:54px}#study-panel>#bone-overlay .close{top:0;right:0}
@media(max-width:950px){.workspace{gap:28px;grid-template-columns:minmax(300px,1fr) minmax(0,1fr)}.sl-viewer{height:350px}.answer-mark{display:none}}
@media(max-width:740px){body{font-size:16px}.masthead{padding:12px 18px}.brand{font-size:30px}#classroom{padding:0 18px 18px}.lesson-heading{padding:22px 0}.lesson-heading h1{font-size:28px}.workspace{display:flex;flex-direction:column;gap:24px}.step-card{width:100%;padding:0}.step-card h2{font-size:28px;margin-bottom:20px}.step-card p{margin-bottom:18px}.model-card{position:relative;top:0;width:100%;border-radius:16px}.sl-viewer{height:290px}.model-heading{padding:12px;font-size:12px}.tools button{padding:9px 10px;font-size:12px}.gesture{font-size:10px}.options button{font-size:15px;padding:14px 12px}.options{gap:10px}.letter{width:23px;height:23px}.answer-mark{display:none}#step-footer{padding-top:14px;gap:10px;flex-direction:column-reverse;align-items:stretch;margin-top:22px}#step-footer .primary{width:100%;min-width:0}.autosave{text-align:center;font-size:10px}.credits{margin-top:8px}#bone-overlay{padding:18px}#bone-overlay h2{font-size:25px}.workspace.text-only{max-width:none}.look-note{font-size:13px}.kicker,.eyebrow{font-size:10px}.sutures{flex-wrap:wrap}}
.showing-suture .color-dot{background:#ffe234;box-shadow:0 0 0 1px #524019}.suture-legend{padding:0 0 12px;font-size:13px;line-height:1.5}.suture-key{display:flex;align-items:center;gap:8px;margin:0 0 9px;font-weight:700}.suture-key>span{width:25px;height:6px;flex:none;background:#ffe234;border:1px solid #524019;border-radius:3px}.suture-neighbours{display:flex;flex-wrap:wrap;gap:6px 18px}.suture-neighbours>span{display:flex;align-items:center;gap:7px}.suture-neighbours i{width:10px;height:10px;border-radius:50%;border:1px solid #0003;flex:none}.suture-neighbours .first{background:#ed6999}.suture-neighbours .second{background:#48ad99}.suture-note{font-size:11px;color:var(--muted);margin:8px 0 0}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;transition:none!important}}
/* Book index: a contents page, with a single next action and numbered chapters. */
.masthead nav{display:flex;align-items:center;gap:24px}.masthead nav a{white-space:nowrap}
#book-index{max-width:1000px;margin:0 auto;padding-bottom:40px}#book-index:focus{outline:none}.book-heading{padding:46px 0 28px}.book-heading h1{font-size:clamp(34px,5vw,58px);margin-bottom:18px}.book-heading>p:last-child{color:var(--muted);max-width:550px;margin-bottom:0}.continue-strip{display:flex;align-items:center;justify-content:space-between;gap:28px;padding:26px 30px;border:1px solid #d8aab7;border-left:5px solid var(--pink);border-radius:4px 16px 16px 4px;background:var(--pink-soft);margin-bottom:40px}.continue-strip h2{font-size:27px;margin-bottom:7px}.continue-strip .kicker{margin-bottom:7px}.continue-strip p:last-child{font-size:13px;margin:0}.continue-strip button{flex:none}.index-heading{display:flex;justify-content:space-between;align-items:center;gap:16px;padding-bottom:12px;border-bottom:2px solid var(--ink)}.index-heading h2{font-size:23px;margin:0}.index-heading>span{font:10px var(--mono);color:var(--muted)}.chapter-list{padding:0;margin:0;list-style:none}.chapter-list>li{display:grid;grid-template-columns:44px 1fr auto;gap:22px;padding:30px 0;border-bottom:1px solid var(--line);align-items:start}.chapter-number{font:20px var(--mono);padding-top:20px;color:#ad3764}.chapter-copy h3{font-size:25px;letter-spacing:-.025em;margin:4px 0 9px;line-height:1.2}.chapter-copy h3 a{text-decoration:none}.chapter-copy h3 a:hover{text-decoration:underline}.chapter-copy p{font-size:15px;margin-bottom:8px}.chapter-copy .chapter-status{font:10px/1.6 var(--mono);color:var(--muted);margin:0}.chapter-meta{font-size:12px;color:var(--muted)}.chapter-actions{display:flex;flex-direction:column;align-items:stretch;min-width:100px;padding-top:18px}.chapter-actions .text-button{padding:10px}.index-atlas{display:flex;align-items:center;justify-content:space-between;gap:20px;margin:30px 0;padding:24px 0}.index-atlas h2{font-size:23px;margin-bottom:8px}.index-atlas p{font-size:14px;color:var(--muted);margin:0}.atlas-link{font-size:14px;flex:none;padding:12px 0}.index-note{max-width:640px}.match-rows{display:grid;gap:18px;margin:24px 0}.match-row{display:grid;gap:9px;font-size:16px;padding:16px;border:1px solid var(--line);border-radius:12px;background:#fffdf8}.match-row>span{font-weight:700}.match-row select{width:100%;min-width:0;max-width:100%;padding:11px 9px;border:1px solid #aeb4a9;border-radius:8px;background:var(--paper);font-size:14px}.match-row small{font-size:13px;color:#37591c}.match-row.matched{border-color:#6b8d40;background:#edf6dc}.match-row.unmatched{border-color:#b47751;background:#fff0e7}.match-row select:disabled{opacity:1;color:var(--ink)}.session-evidence{font-size:15px;border-left:3px solid var(--pink);padding:10px 16px}.summary-actions{margin:18px 0}.review-note .quiet-copy{margin:16px 0 0}
@media(max-width:740px){.masthead nav{gap:15px}.masthead nav a{font-size:11px}.book-heading{padding:28px 0 24px}.book-heading h1{font-size:36px}.book-heading>p:last-child{font-size:15px}.continue-strip{padding:21px;flex-direction:column;align-items:stretch;gap:20px;margin-bottom:30px}.continue-strip h2{font-size:25px}.continue-strip .primary{font-size:15px;padding-inline:12px}.index-heading{align-items:start}.index-heading>span{max-width:95px;text-align:right;line-height:1.6}.chapter-list>li{grid-template-columns:28px minmax(0,1fr);gap:12px;padding:25px 0}.chapter-number{font-size:16px}.chapter-copy h3{font-size:23px}.chapter-actions{grid-column:2;flex-direction:row;gap:18px;padding:0}.chapter-actions button{min-width:100px}.index-atlas{flex-direction:column;align-items:start;gap:8px;padding:0}.index-note{font-size:13px}.match-row{padding:13px}.match-row select{font-size:13px}.index-heading h2{font-size:21px}}
/* Manual "ya la estudié" marks, neighbour-only legends and cross-class review links. */
.sr-only{position:absolute!important;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0 0 0 0);clip-path:inset(50%);white-space:nowrap;border:0}.manual-status{color:#2f5a17;font-weight:700}.manual-note{font-size:13px;line-height:1.55;color:var(--muted);border-left:3px solid var(--lime);padding:6px 12px;margin:12px 0 0}.chapter-actions .text-button+.text-button{padding-top:0}.suture-key.untraced{font-weight:600}.suture-key.untraced::before{content:'';width:25px;height:0;flex:none;border-top:2px dashed #8b8f84}.summary-actions{display:flex;flex-wrap:wrap;gap:10px}.review-note li a{font-weight:600}
@media(max-width:740px){.chapter-actions{flex-wrap:wrap;gap:4px 18px}.chapter-actions .text-button+.text-button{padding-top:12px}}

.index-tools{display:flex;flex-direction:column;align-items:flex-end;gap:4px}.index-tools .text-button{min-height:44px}
@media(max-width:740px){.index-tools{align-items:flex-start}}

/* Cuaderno de anatomía: el índice comparte el lenguaje visual de La célula. */
#book-index{max-width:824px}
#book-index .book-heading{display:grid;grid-template-columns:minmax(0,1fr) 174px;align-items:center;gap:28px;padding:32px 0 28px}
#book-index .book-heading-copy{min-width:0}
#book-index .book-heading .eyebrow{font:11px/1.6 var(--mono);letter-spacing:.07em;color:#2f5d4b;margin-bottom:12px}
#book-index .book-heading h1{font-size:clamp(36px,4.4vw,58px);letter-spacing:-.055em;line-height:1.08;margin-bottom:18px;text-wrap:balance}
#book-index .book-heading-copy>p:last-child{color:var(--muted);font-size:17px;line-height:1.7;max-width:44ch;margin-bottom:0}
#book-index .book-emblem{position:relative;align-self:center;transform:rotate(5deg);pointer-events:none}
#book-index .book-emblem svg{display:block;width:100%;height:auto}
#book-index .book-emblem>span{display:block;text-align:center;font:700 10px/1.6 var(--mono);letter-spacing:.05em;color:#795344;transform:rotate(-5deg);margin-top:-6px}
#book-index .continue-strip{position:relative;isolation:isolate;overflow:hidden;align-items:flex-start;flex-direction:column;gap:20px;padding:24px;border:1px solid #d8bcad;border-radius:18px;background:linear-gradient(150deg,#fff0e4,#f6e3df);box-shadow:0 1px 0 #ffffff inset,0 10px 30px -18px #3b33204d;margin-bottom:32px}
#book-index .continue-strip::after{content:'';position:absolute;z-index:-1;right:-38px;top:-48px;width:150px;height:150px;border:19px solid #eacac2;border-radius:45% 55% 48% 52%;transform:rotate(25deg);box-shadow:0 0 0 17px #f1ded0;opacity:.65}
#book-index .continue-strip .kicker{display:inline-block;padding:5px 10px;background:#eed7c3;border-radius:999px;font:700 11px/1.4 var(--mono);letter-spacing:.07em;color:#795344;margin:0 0 12px}
#book-index .continue-strip h2{font-size:27px;line-height:1.15;margin-bottom:10px}
#book-index .continue-strip p:last-child{font-size:14px;line-height:1.6}
#book-index .continue-strip .primary{width:100%;border-width:1px;border-radius:12px;box-shadow:4px 4px 0 var(--lime)}
#book-index .index-heading{border-bottom:1px solid var(--line);padding-bottom:16px;gap:18px}
#book-index .index-heading h2{font-size:24px}
#book-index .index-heading>span{font:11px/1.6 var(--mono);background:#edf2e3;color:#3a5b48;padding:5px 10px;border-radius:999px;text-align:center}
#book-index .chapter-list>li{grid-template-columns:40px minmax(0,1fr) auto;gap:16px;padding:24px 0}
#book-index .chapter-number{display:grid;place-items:center;align-self:start;min-height:40px;font:700 13px/1 var(--mono);color:#8c4563;background:#f9e3ec;border:1px solid #eed0dd;border-radius:11px;padding:8px 0;margin-top:3px}
#book-index .chapter-copy h3{font-size:23px;margin:7px 0 9px;line-height:1.2;text-wrap:balance}
#book-index .chapter-copy .chapter-status{font-size:11px;line-height:1.6}
#book-index .chapter-copy p{font-size:15px;line-height:1.6}
#book-index .chapter-actions{padding-top:18px;min-width:100px}
#book-index .chapter-actions .secondary{background:#fffdf7;border-radius:11px;font-size:14px}
#book-index .index-atlas{margin:28px 0;padding:22px 24px;background:#edf2e3;border:1px solid #d0dcc1;border-radius:18px;box-shadow:0 1px 0 #fff inset}
#book-index .index-atlas h2{font-size:23px;color:#2f5d4b}
#book-index .index-atlas .atlas-link{font-weight:700}
#book-index .index-note{max-width:68ch}
@media(max-width:740px){
 #book-index .book-heading{grid-template-columns:minmax(0,1fr) 88px;gap:14px;padding:24px 0}
 #book-index .book-heading h1{font-size:36px;margin-bottom:12px;text-wrap:wrap}
 #book-index .book-heading-copy>p:last-child{font-size:15px}
 #book-index .book-heading .eyebrow{font-size:11px}
 #book-index .book-emblem{align-self:start;margin-top:35px}
 #book-index .book-emblem>span{display:none}
 #book-index .continue-strip{padding:20px;margin-bottom:28px}
 #book-index .continue-strip h2{font-size:25px}
 #book-index .index-heading h2{font-size:22px}
 #book-index .index-heading>span{max-width:110px;font-size:11px}
 #book-index .chapter-list>li{grid-template-columns:32px minmax(0,1fr);gap:10px 12px;padding:22px 0}
 #book-index .chapter-number{min-height:34px;font-size:12px;border-radius:9px}
 #book-index .chapter-copy h3{font-size:22px}
 #book-index .chapter-copy p{font-size:14px}
 #book-index .chapter-actions{grid-column:2;padding:0;gap:4px 12px}
 #book-index .index-atlas{align-items:stretch;padding:20px;gap:14px}
}
@media(max-width:360px){
 #book-index .book-heading{grid-template-columns:minmax(0,1fr) 66px;gap:8px}
 #book-index .book-heading h1{font-size:32px}
 #book-index .book-heading .eyebrow{font-size:11px;letter-spacing:.02em}
}

.lesson-figures{display:flex;flex-direction:column;align-items:flex-start;gap:4px;margin:12px 0}.lesson-figures .text-button{text-align:left;min-height:44px;line-height:1.5;white-space:normal}