:root{
  --bg:#0b1117;--surface:#111a22;--surface2:#16212b;--surface3:#1b2935;--text:#edf4f8;
  --muted:#8fa3b4;--line:#263746;--accent:#39c6b4;--accent2:#7ce0d3;--warn:#f2bd5b;
  --danger:#f07777;--good:#63d49b;--shadow:0 18px 45px rgba(0,0,0,.24);--radius:18px;
}
body.light{
  --bg:#eef3f5;--surface:#ffffff;--surface2:#f5f8f9;--surface3:#eaf0f2;--text:#14222c;
  --muted:#607381;--line:#d7e1e5;--shadow:0 14px 40px rgba(22,40,52,.10);
}
*{box-sizing:border-box}
html,body{margin:0;min-height:100%;font-family:Inter,ui-sans-serif,system-ui,-apple-system,Segoe UI,sans-serif;background:var(--bg);color:var(--text)}
button,textarea{font:inherit}
button{cursor:pointer}
.app-shell{display:flex;min-height:100vh}
.sidebar{width:272px;background:#081016;border-right:1px solid var(--line);padding:22px 18px;position:fixed;inset:0 auto 0 0;display:flex;flex-direction:column;z-index:20;transition:.25s}
body.light .sidebar{background:#f8fbfc}
.sidebar.collapsed{width:82px}
.sidebar.collapsed .brand>div:last-child,.sidebar.collapsed .nav-item:not(.active){font-size:0}
.sidebar.collapsed .nav-item span{font-size:18px}
.sidebar.collapsed .sidebar-bottom{display:none}
.brand{display:flex;align-items:center;gap:12px;padding:4px 6px 22px}
.brand-mark{height:42px;width:42px;border-radius:13px;display:grid;place-items:center;background:linear-gradient(135deg,var(--accent),#207d78);font-weight:900;color:#04110f}
.brand-name{font-weight:900;letter-spacing:.08em;font-size:14px}
.brand-sub{color:var(--muted);font-size:11px;margin-top:3px}
.nav{display:grid;gap:6px}
.nav-item{border:0;background:transparent;color:var(--muted);padding:11px 12px;border-radius:12px;text-align:left;display:flex;gap:11px;align-items:center}
.nav-item:hover,.nav-item.active{background:var(--surface2);color:var(--text)}
.nav-item.active{box-shadow:inset 3px 0 0 var(--accent)}
.sidebar-bottom{margin-top:auto}
.mini-progress{padding:14px;background:var(--surface);border:1px solid var(--line);border-radius:14px}
.mini-progress-row{display:flex;justify-content:space-between;font-size:12px;margin-bottom:9px}
.bar{height:7px;background:var(--surface3);border-radius:999px;overflow:hidden}
.fill{height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2));border-radius:999px;transition:.35s}
.ghost-btn,.secondary,.primary,.chip,.icon-btn{border-radius:11px;padding:10px 13px;border:1px solid var(--line)}
.ghost-btn{width:100%;margin-top:10px;background:transparent;color:var(--muted)}
.primary{background:var(--accent);color:#06201d;border-color:transparent;font-weight:800}
.secondary{background:var(--surface2);color:var(--text)}
.icon-btn{background:var(--surface);color:var(--text);width:42px;height:42px;padding:0}
.chip{background:var(--surface2);color:var(--accent2);font-size:12px}
.full{width:100%}
.main{flex:1;margin-left:272px;min-width:0;transition:.25s}
.sidebar.collapsed~.main{margin-left:82px}
.topbar{height:74px;display:flex;align-items:center;gap:16px;padding:0 28px;border-bottom:1px solid var(--line);position:sticky;top:0;background:color-mix(in srgb,var(--bg) 88%, transparent);backdrop-filter:blur(14px);z-index:10}
.breadcrumbs{color:var(--muted);font-size:13px}
.top-actions{margin-left:auto;display:flex;gap:9px}
.view{display:none;padding:28px;max-width:1600px;margin:auto}
.view.active{display:block}
.hero{min-height:330px;border:1px solid var(--line);background:radial-gradient(circle at 78% 48%,rgba(57,198,180,.17),transparent 28%),linear-gradient(145deg,var(--surface),var(--surface2));border-radius:26px;padding:42px;display:grid;grid-template-columns:1.4fr .8fr;overflow:hidden}
.hero h1,.page-title h1{font-size:clamp(32px,4vw,56px);line-height:1.02;margin:10px 0 14px;letter-spacing:-.04em}
.hero p,.page-title p{color:var(--muted);max-width:720px;line-height:1.7}
.eyebrow,.kicker{color:var(--accent2);font-weight:800;letter-spacing:.16em;font-size:11px}
.hero-actions{display:flex;gap:10px;margin-top:24px}
.hero-orbit{position:relative;min-height:250px}
.orbit-center{width:118px;height:118px;border-radius:50%;display:grid;place-items:center;position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);border:1px solid var(--accent);box-shadow:0 0 55px rgba(57,198,180,.2),inset 0 0 30px rgba(57,198,180,.1);font-weight:900;font-size:28px}
.orbit-dot{position:absolute;padding:9px 12px;border:1px solid var(--line);background:var(--surface);border-radius:999px;font-size:12px}
.d1{left:8%;top:22%}.d2{right:6%;top:18%}.d3{left:14%;bottom:16%}.d4{right:4%;bottom:22%}
.metric-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin:16px 0}
.metric{padding:20px;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius)}
.metric-label{display:block;color:var(--muted);font-size:12px}.metric strong{display:block;font-size:28px;margin:7px 0}.metric small{color:var(--muted)}
.grid.two{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow)}
.panel-head,.page-title{display:flex;justify-content:space-between;gap:18px;align-items:flex-start}
.panel h2{margin:5px 0 10px}
.pill{border:1px solid var(--line);background:var(--surface2);padding:7px 10px;border-radius:999px;color:var(--muted);font-size:11px}
.status{color:var(--accent2)}
.system-progress{display:grid;grid-template-columns:130px 1fr;gap:18px;align-items:center;margin:18px 0}
.system-progress-ring{width:118px;height:118px;border-radius:50%;display:grid;place-items:center;background:conic-gradient(var(--accent) 0 24%,var(--surface3) 24%);font-size:22px;font-weight:900;position:relative}
.system-progress-ring:after{content:"";position:absolute;inset:10px;background:var(--surface);border-radius:50%}
.system-progress-ring span{z-index:2}
.clean{list-style:none;padding:0;margin:8px 0;color:var(--muted);line-height:1.85}
.signal-list{display:grid;gap:12px;margin-top:14px}
.signal{display:grid;grid-template-columns:1fr auto;gap:6px;padding:12px;background:var(--surface2);border-radius:12px}
.signal small{grid-column:1/-1;color:var(--muted)}
.signal.good strong{color:var(--good)}.signal.dev strong{color:var(--warn)}.signal.weak strong{color:var(--danger)}
.lab-flow{display:flex;align-items:stretch;gap:10px;overflow:auto;padding-top:8px}
.lab-flow button{min-width:170px;flex:1;text-align:left;padding:16px;border-radius:14px;border:1px solid var(--line);background:var(--surface2);color:var(--text)}
.lab-flow button span{color:var(--accent2);font-size:11px}.lab-flow button strong,.lab-flow button small{display:block;margin-top:7px}.lab-flow button small{color:var(--muted)}
.flow-arrow{display:grid;place-items:center;color:var(--muted)}
.page-title{margin-bottom:22px}.page-title h1{font-size:38px}.page-title p{margin-top:0}
.segmented{display:flex;border:1px solid var(--line);border-radius:12px;padding:4px}.segmented button{border:0;background:transparent;color:var(--muted);padding:8px 12px;border-radius:8px}.segmented .active{background:var(--surface2);color:var(--text)}
.system-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.system-card{position:relative;min-height:180px;padding:20px;background:linear-gradient(145deg,var(--surface),var(--surface2));border:1px solid var(--line);border-radius:18px;overflow:hidden}
.system-card h3{font-size:21px;margin:8px 0}.system-card p{color:var(--muted);font-size:13px;line-height:1.5}.system-card button{position:absolute;right:15px;bottom:15px}
.system-card.locked{opacity:.58}
.module-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.module-card{padding:20px;border:1px solid var(--line);background:var(--surface);border-radius:17px}
.module-card>span{color:var(--accent2);font-weight:800}.module-card h3{margin:12px 0 8px}.module-card p{color:var(--muted);font-size:13px;line-height:1.6;min-height:62px}
.module-card button{width:100%;padding:9px;border:1px solid var(--line);border-radius:10px;background:var(--surface2);color:var(--text)}
.module-card.current{outline:1px solid var(--accent);box-shadow:0 0 0 4px rgba(57,198,180,.06)}.module-card.locked{opacity:.5}
.explorer-layout{display:grid;grid-template-columns:220px minmax(420px,1fr) 320px;gap:14px}
.structure-list{display:grid;gap:7px;align-content:start}
.structure-list button{padding:12px;border-radius:11px;border:1px solid var(--line);background:var(--surface);color:var(--muted);text-align:left}.structure-list button.active{color:var(--text);border-color:var(--accent)}
.structure-stage{min-height:540px;display:grid;place-items:center}
.heart-diagram{width:min(500px,90%);height:430px;border-radius:46% 46% 48% 48%;border:2px solid rgba(57,198,180,.45);position:relative;background:radial-gradient(circle at 50% 48%,rgba(240,119,119,.18),transparent 45%),var(--surface2);box-shadow:inset 0 0 80px rgba(57,198,180,.06)}
.heart-core{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);font-weight:900;color:rgba(255,255,255,.12);font-size:58px}
.anatomy-node{position:absolute;border:1px solid var(--line);background:var(--surface);color:var(--text);border-radius:999px;padding:8px 11px;font-size:11px}.anatomy-node:hover{border-color:var(--accent)}
.n-ra{left:10%;top:20%}.n-rv{left:18%;bottom:18%}.n-la{right:10%;top:19%}.n-lv{right:15%;bottom:17%}.n-tv{left:31%;top:47%}.n-mv{right:31%;top:47%}
.detail-panel h2{margin-top:6px}.detail-panel p,.detail-panel li{color:var(--muted);line-height:1.6;font-size:13px}.detail-table{display:grid;gap:10px;margin-top:16px}.detail-row{padding:11px;background:var(--surface2);border-radius:10px}.detail-row span{display:block;color:var(--accent2);font-size:10px;font-weight:800;letter-spacing:.1em;margin-bottom:4px}
.pathway-layout{grid-template-columns:1.3fr .7fr;gap:14px}.pathway-map{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.path-node{padding:13px 15px;border-radius:12px;border:1px solid var(--line);background:var(--surface2);color:var(--text)}.path-node.active{border-color:var(--accent);box-shadow:0 0 0 3px rgba(57,198,180,.08)}.path-arrow{color:var(--muted)}
.pathway-detail min-height:180px
.sequence-builder{margin-top:14px}.sequence-options,.sequence-answer{display:flex;flex-wrap:wrap;gap:8px;margin:13px 0}.seq-chip{border:1px solid var(--line);background:var(--surface2);color:var(--text);padding:9px 11px;border-radius:999px}.sequence-answer{min-height:54px;padding:10px;border:1px dashed var(--line);border-radius:12px}.feedback{min-height:28px;color:var(--muted);margin:7px 0}
.histology-stage{min-height:430px}.micrograph-sim{height:370px;position:relative;overflow:hidden;border-radius:16px;background:linear-gradient(20deg,#321c25,#623143 45%,#2a2636);border:1px solid var(--line)}
.fiber{position:absolute;height:72px;width:110%;left:-5%;border-radius:60%;background:repeating-linear-gradient(90deg,rgba(255,220,225,.30) 0 9px,rgba(93,34,48,.2) 9px 18px);transform:rotate(-8deg)}
.f1{top:40px}.f2{top:130px}.f3{top:220px}.f4{top:300px}.disc{position:absolute;width:8px;height:310px;background:rgba(30,20,30,.8);top:30px;transform:rotate(-8deg)}.d-a{left:38%}.d-b{left:67%}
.hotspot{position:absolute;width:36px;height:36px;border-radius:50%;border:2px solid white;background:rgba(57,198,180,.8);color:#051513;font-weight:900}.h1{left:37%;top:26%}.h2{left:56%;top:53%}.h3{left:75%;top:30%}
.clinical-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.clinical-card{padding:20px;background:var(--surface);border:1px solid var(--line);border-radius:16px}.clinical-card h3{margin:8px 0}.clinical-card p{color:var(--muted);font-size:13px;line-height:1.6}.reason-chain{display:grid;gap:6px;margin-top:13px}.reason-chain span{padding:8px;background:var(--surface2);border-radius:9px;font-size:12px}
.practice-layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:14px}.quiz-card{min-height:430px}.quiz-q{font-size:24px;line-height:1.35;margin:15px 0 22px}.answer-grid{display:grid;gap:9px}.answer-btn{padding:14px;text-align:left;border:1px solid var(--line);background:var(--surface2);color:var(--text);border-radius:11px}.answer-btn.correct{border-color:var(--good);background:rgba(99,212,155,.1)}.answer-btn.wrong{border-color:var(--danger);background:rgba(240,119,119,.09)}.quiz-explain{margin-top:16px;padding:14px;border-left:3px solid var(--accent);background:var(--surface2);color:var(--muted);line-height:1.6}
.score-big{font-size:42px;font-weight:900;margin:12px 0}.breakdown{display:grid;gap:8px;margin:18px 0}.breakdown div{display:flex;justify-content:space-between;font-size:13px;color:var(--muted)}
.exam-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}.exam-card{padding:22px;border:1px solid var(--line);background:var(--surface);border-radius:18px}.exam-icon{display:grid;place-items:center;width:54px;height:54px;border-radius:15px;background:var(--surface2);font-weight:900;color:var(--accent2)}.exam-card p{color:var(--muted);font-size:13px;line-height:1.6}.exam-card button{width:100%}.exam-card.locked{opacity:.55}
.mastery-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.mastery-card{padding:16px;background:var(--surface);border:1px solid var(--line);border-radius:14px}.mastery-card-head{display:flex;justify-content:space-between;gap:8px}.mastery-state{font-size:11px}.mastery-state.mastered{color:var(--good)}.mastery-state.developing{color:var(--warn)}.mastery-state.weak{color:var(--danger)}.mastery-state.unstudied{color:var(--muted)}
.mastery-card p{color:var(--muted);font-size:12px}
textarea{width:100%;min-height:370px;resize:vertical;background:var(--surface2);color:var(--text);border:1px solid var(--line);border-radius:13px;padding:15px;line-height:1.6}
.autosave{font-size:11px;color:var(--good)}
.flashcard{height:330px;border:1px solid var(--line);background:linear-gradient(145deg,var(--surface2),var(--surface3));border-radius:18px;display:grid;place-items:center;text-align:center;padding:34px;position:relative;overflow:hidden}.flash-front,.flash-back{font-size:24px;line-height:1.4}.flash-back{display:none;color:var(--accent2)}
.flashcard.flipped .flash-front{display:none}.flashcard.flipped .flash-back{display:block}.flash-controls{display:flex;align-items:center;justify-content:space-between}.flash-controls .ghost-btn{width:auto}
.toast{position:fixed;right:22px;bottom:22px;padding:12px 15px;border-radius:12px;background:var(--text);color:var(--bg);font-weight:700;opacity:0;transform:translateY(10px);pointer-events:none;transition:.25s;z-index:99}.toast.show{opacity:1;transform:none}
@media(max-width:1100px){.metric-grid,.module-grid,.exam-grid{grid-template-columns:repeat(2,1fr)}.explorer-layout{grid-template-columns:190px 1fr}.detail-panel{grid-column:1/-1}.system-grid,.clinical-grid,.mastery-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:760px){.sidebar{transform:translateX(-100%);width:272px}.sidebar.mobile-open{transform:none}.main,.sidebar.collapsed~.main{margin-left:0}.topbar{padding:0 14px}.view{padding:18px 14px}.hero{grid-template-columns:1fr;padding:25px}.hero-orbit{display:none}.metric-grid,.grid.two,.system-grid,.module-grid,.clinical-grid,.exam-grid,.mastery-grid,.practice-layout,.pathway-layout{grid-template-columns:1fr}.explorer-layout{grid-template-columns:1fr}.structure-list{grid-template-columns:repeat(2,1fr)}.system-progress{grid-template-columns:1fr}.lab-flow{display:grid;grid-template-columns:1fr 1fr}.flow-arrow{display:none}.page-title{display:block}.segmented{margin-top:12px;width:max-content}}

.cardio-overview{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-bottom:16px}
.stat-panel{box-shadow:none}.stat-panel strong{display:block;font-size:34px;margin:8px 0}.stat-panel small{color:var(--muted)}
.conduction-map{display:grid;gap:10px;margin-top:16px}
.conduction-step{display:grid;grid-template-columns:42px 1fr;gap:12px;align-items:center;padding:13px;border:1px solid var(--line);background:var(--surface2);border-radius:13px}
.conduction-step .pulse{width:34px;height:34px;border-radius:50%;display:grid;place-items:center;background:var(--surface3);color:var(--accent2);font-weight:900}
.conduction-step.active{border-color:var(--accent);box-shadow:0 0 0 3px rgba(57,198,180,.08)}
.conduction-step.active .pulse{background:var(--accent);color:#06201d;box-shadow:0 0 22px rgba(57,198,180,.42)}
.ecg-panel{margin-top:14px}.ecg-track{position:relative;min-height:180px;background:linear-gradient(rgba(57,198,180,.08) 1px,transparent 1px),linear-gradient(90deg,rgba(57,198,180,.08) 1px,transparent 1px);background-size:24px 24px;border-radius:14px;overflow:hidden;padding:58px 22px}
.ecg-line{font-family:monospace;font-size:32px;letter-spacing:3px;color:var(--accent2);white-space:nowrap;opacity:.85}
.ecg-marker{position:absolute;border:1px solid var(--line);background:var(--surface);color:var(--text);border-radius:9px;padding:7px 10px}.ecg-marker.p{left:18%;top:28px}.ecg-marker.qrs{left:47%;top:22px}.ecg-marker.t{left:76%;top:34px}
.ecg-detail{margin-top:15px;padding:14px;border-radius:12px;background:var(--surface2);color:var(--muted);line-height:1.6}
.cycle-layout{display:grid;grid-template-columns:1fr .8fr;gap:14px;margin-bottom:14px}
.cycle-ring{display:grid;grid-template-columns:repeat(5,1fr);gap:10px}
.cycle-phase{padding:18px 12px;border:1px solid var(--line);background:var(--surface2);color:var(--text);border-radius:14px;text-align:left}
.cycle-phase.active{border-color:var(--accent);background:rgba(57,198,180,.08)}
.cycle-phase span{display:block;color:var(--accent2);font-size:10px;margin-bottom:8px}.cycle-phase strong{display:block}
.pressure-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}
.pressure-grid div{padding:14px;background:var(--surface2);border-radius:12px}.pressure-grid span{display:block;color:var(--muted);font-size:12px;margin-bottom:6px}
.hemo-grid{display:grid;grid-template-columns:1fr 1fr 1fr;gap:14px}.hemo-grid label{display:grid;gap:8px;margin:18px 0;color:var(--muted)}.hemo-grid input[type=range]{width:100%}
.hemo-output{padding:14px;background:var(--surface2);border-radius:12px;margin:10px 0}.hemo-output span,.hemo-output small{display:block;color:var(--muted)}.hemo-output strong{display:block;font-size:25px;margin:5px 0}
.formula{padding:14px;border-left:3px solid var(--accent);background:var(--surface2);margin:10px 0;border-radius:9px;font-weight:700}
@media(max-width:1100px){.cardio-overview,.hemo-grid{grid-template-columns:repeat(2,1fr)}.cycle-layout{grid-template-columns:1fr}}
@media(max-width:760px){.cardio-overview,.hemo-grid,.pressure-grid{grid-template-columns:1fr}.cycle-ring{grid-template-columns:1fr 1fr}}

.airway-panel{margin-top:16px}.airway-chain{display:flex;flex-wrap:wrap;gap:8px;align-items:center}.air-step{padding:11px 13px;border:1px solid var(--line);background:var(--surface2);color:var(--text);border-radius:12px}.air-step.active{border-color:var(--accent);box-shadow:0 0 0 3px rgba(57,198,180,.08)}
.breathing-cycle{margin-top:14px}
.vq-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.vq-card{padding:18px;border:1px solid var(--line);background:var(--surface2);color:var(--text);border-radius:14px;text-align:left}.vq-card strong,.vq-card span{display:block}.vq-card span{color:var(--muted);font-size:12px;margin-top:6px}.vq-card.active{border-color:var(--accent)}
@media(max-width:760px){.vq-grid{grid-template-columns:1fr}}