:root{color:#211f1c;background:#f7f3ee;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;--gold: #b88a44;--gold-dark: #8a632b;--ink: #211f1c;--muted: #6e675f;--line: #ded4c7;--surface: #fffdf9;--surface-strong: #fff8ef;--success: #2f7a4f;--danger: #a33d35}*{box-sizing:border-box}body{margin:0;min-width:320px;min-height:100vh}button{font:inherit}.welcome-shell{display:grid;min-height:100vh;place-items:center;padding:24px;background:linear-gradient(120deg,rgba(184,138,68,.14),transparent 42%),radial-gradient(circle at top right,rgba(33,31,28,.08),transparent 34%),#f7f3ee}.welcome{width:min(860px,100%);padding:clamp(28px,6vw,76px);border:1px solid var(--line);border-radius:8px;background:#fffdf9e0;box-shadow:0 24px 70px #211f1c1c}.welcome h1,.app-header h1,.panel h2,.viewer-header h2,.quiz-panel h2{margin:0;letter-spacing:0;color:var(--ink)}.welcome h1{max-width:780px;font-size:clamp(2.2rem,6vw,5.2rem);line-height:.98}.welcome-copy{max-width:680px;margin:24px 0 32px;color:var(--muted);font-size:clamp(1rem,2vw,1.2rem);line-height:1.65}.eyebrow{margin:0 0 9px;color:var(--gold-dark);font-size:.76rem;font-weight:800;letter-spacing:.08em;text-transform:uppercase}.primary-button,.ghost-button,.option-button,.muscle-item{min-height:44px;border-radius:8px;cursor:pointer;transition:transform .16s ease,border-color .16s ease,background .16s ease,color .16s ease}.primary-button{border:1px solid var(--ink);background:var(--ink);color:#fff;padding:14px 20px;font-weight:800}.primary-button:hover,.ghost-button:hover,.option-button:hover,.muscle-item:hover{transform:translateY(-1px)}.primary-button:disabled{cursor:not-allowed;opacity:.42;transform:none}.primary-button.compact{min-height:40px;padding:10px 16px}.ghost-button{border:1px solid var(--line);background:#fff;color:var(--ink);padding:11px 16px;font-weight:800}.ghost-button.dark{border-color:var(--ink)}.app-shell{width:min(1440px,100%);margin:0 auto;padding:20px}.app-header{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-bottom:20px;padding:18px 0}.app-header h1{font-size:clamp(1.6rem,4vw,3.1rem);line-height:1.05}.learning-grid{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(260px,.55fr);grid-template-areas:"viewer list" "info list";gap:18px}.zone-selector{margin-bottom:18px;border:1px solid var(--line);border-radius:8px;background:var(--surface);padding:18px;box-shadow:0 16px 42px #211f1c12}.zone-selector-header{display:flex;align-items:flex-start;justify-content:space-between;gap:18px;margin-bottom:14px}.zone-selector-header h2{margin:0;color:var(--ink);font-size:1.28rem;letter-spacing:0}.zone-selector-header p:last-child{max-width:540px;margin:0;color:var(--muted);line-height:1.55}.zone-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px}.zone-card{min-height:128px;border:1px solid var(--line);border-radius:8px;background:#fff;color:var(--ink);padding:12px;text-align:left;cursor:pointer;transition:transform .16s ease,border-color .16s ease,background .16s ease}.zone-card:hover{border-color:var(--gold);transform:translateY(-1px)}.zone-card.active{border-color:#a9442f;background:#fff2ed}.zone-card:disabled{cursor:not-allowed;opacity:.62;transform:none}.zone-card-topline{display:grid;gap:8px}.zone-name{font-weight:850;line-height:1.25}.zone-status{width:fit-content;border-radius:999px;padding:4px 8px;font-size:.72rem;font-weight:850}.zone-status.available{background:#2f7a4f1a;color:var(--success)}.zone-status.planned{background:#eee5da;color:var(--muted)}.zone-description{display:block;margin-top:10px;color:var(--muted);font-size:.88rem;line-height:1.45}.viewer-area{grid-area:viewer}.side-panel{grid-area:list}.info-area{grid-area:info}.panel,.viewer-card{border:1px solid var(--line);border-radius:8px;background:var(--surface);box-shadow:0 16px 42px #211f1c12}.panel{padding:18px}.panel-heading{margin-bottom:16px}.panel h2,.viewer-header h2,.quiz-panel h2{font-size:1.28rem}.viewer-card{overflow:hidden}.viewer-header{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:18px 18px 10px}.viewer-header-actions{display:grid;justify-items:end;gap:9px}.viewer-availability{margin:8px 0 0;color:var(--danger);font-size:.86rem;font-weight:800}.viewer-chip,.score-pill{display:inline-flex;align-items:center;justify-content:center;min-height:30px;border-radius:999px;background:#f0e4d2;color:var(--gold-dark);padding:6px 10px;font-size:.78rem;font-weight:800;white-space:nowrap}.viewer-controls{display:flex;flex-wrap:wrap;justify-content:flex-end;gap:7px}.viewer-control{min-height:34px;border:1px solid var(--line);border-radius:8px;background:#fff;color:var(--ink);padding:7px 10px;cursor:pointer;font-size:.78rem;font-weight:800}.viewer-control.active{border-color:#a9442f;background:#fff2ed;color:#7b2e22}.viewer-control:hover{border-color:var(--gold)}.viewer-control:disabled{cursor:not-allowed;opacity:.48}.canvas-wrap{position:relative;height:clamp(330px,52vw,570px);width:100%;border-block:1px solid var(--line);background:#f7f3ee}.model-loading-overlay{position:absolute;top:0;right:0;bottom:0;left:0;z-index:5;display:grid;place-items:center;padding:18px;background:#f7f3eeb8;-webkit-backdrop-filter:blur(2px);backdrop-filter:blur(2px);pointer-events:none}.model-loading-card{display:grid;grid-template-columns:auto minmax(0,1fr);align-items:center;gap:18px;width:min(420px,100%);border:1px solid rgba(184,138,68,.36);border-radius:8px;background:#fffdf9f5;padding:18px;box-shadow:0 22px 60px #211f1c29}.model-loading-ring{--progress: 0deg;display:grid;width:96px;aspect-ratio:1;place-items:center;border-radius:50%;background:radial-gradient(circle,#fffdf9 58%,transparent 60%),conic-gradient(var(--gold) var(--progress),#eee5da 0)}.model-loading-ring.indeterminate{background:radial-gradient(circle,#fffdf9 58%,transparent 60%),conic-gradient(var(--gold) 0 80deg,#eee5da 80deg 360deg);animation:loading-spin .9s linear infinite}.model-loading-ring span{color:var(--ink);font-size:1.42rem;font-weight:900}.model-loading-title{margin:0;color:var(--ink);font-size:1rem;font-weight:900;line-height:1.25}.model-loading-detail,.model-loading-meta{margin:6px 0 0;color:var(--muted);line-height:1.45}.model-loading-meta{font-size:.82rem;font-weight:800}@keyframes loading-spin{to{transform:rotate(360deg)}}.viewer-badge{min-width:190px;border:1px solid var(--line);border-radius:8px;background:#fffdf9f0;color:var(--ink);padding:10px 12px;text-align:center;font-weight:800;box-shadow:0 12px 30px #211f1c1f}.viewer-note{margin:0;padding:13px 18px 16px;color:var(--muted);font-size:.92rem;line-height:1.55}.muscle-list{display:grid;gap:8px;max-height:640px;overflow:auto;padding-right:4px}.muscle-item{width:100%;border:1px solid var(--line);background:#fff;color:var(--ink);padding:11px 12px;text-align:left;font-weight:750}.muscle-item-name,.muscle-item-group{display:block}.muscle-item-group{margin-top:3px;color:var(--muted);font-size:.76rem;font-weight:750}.muscle-item.active{border-color:var(--gold);background:var(--surface-strong);color:#5f421d}.info-panel{min-height:100%}.info-sections{display:grid;gap:14px}.info-sections h3{margin:0 0 4px;color:var(--ink);font-size:.92rem}.info-sections p{margin:0;color:var(--muted);line-height:1.62}.quiz-section{margin:18px 0 34px}.quiz-panel{max-width:980px}.quiz-topline,.quiz-actions{display:flex;align-items:center;justify-content:space-between;gap:14px}.quiz-progress{height:8px;margin:18px 0;overflow:hidden;border-radius:999px;background:#eee5da}.quiz-progress span{display:block;height:100%;border-radius:inherit;background:var(--gold);transition:width .18s ease}.question-counter{margin:0 0 8px;color:var(--muted);font-weight:750}.question-title{margin:0 0 16px;color:var(--ink);font-size:1.12rem;line-height:1.4}.options-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.option-button{border:1px solid var(--line);background:#fff;color:var(--ink);padding:13px;text-align:left;font-weight:750}.option-button:disabled{cursor:default;transform:none}.option-button.correct{border-color:#2f7a4f8c;background:#2f7a4f1a}.option-button.incorrect{border-color:#a33d3580;background:#a33d351a}.feedback{margin:14px 0 0;border-radius:8px;padding:12px;line-height:1.55}.correct-text{background:#2f7a4f1a;color:var(--success)}.incorrect-text{background:#a33d351a;color:var(--danger)}.quiz-actions{justify-content:flex-start;margin-top:16px}@media(max-width:980px){.zone-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.learning-grid{grid-template-columns:1fr;grid-template-areas:"viewer" "list" "info"}.muscle-list{grid-template-columns:repeat(2,minmax(0,1fr));max-height:none}}@media(max-width:640px){.app-shell{padding:14px}.app-header,.zone-selector-header,.viewer-header,.quiz-topline{align-items:flex-start;flex-direction:column}.welcome{padding:24px}.canvas-wrap{height:360px}.muscle-list,.zone-grid,.options-grid{grid-template-columns:1fr}.panel,.viewer-header{padding:15px}}