:root{
  --bg:#0b1220;
  --surface:#111a2e;
  --surface-2:#17233f;
  --border:#25324f;
  --text:#e6edf7;
  --muted:#94a3b8;
  --primary:#3b82f6;
  --primary-2:#2563eb;
  --success:#10b981;
  --danger:#ef4444;
  --warn:#f59e0b;
  --accent:#8b5cf6;
  --radius:12px;
  --shadow:0 8px 24px rgba(0,0,0,.25);
}
html.light{
  --bg:#f6f8fc;
  --surface:#ffffff;
  --surface-2:#f0f4fb;
  --border:#dbe3f0;
  --text:#0f172a;
  --muted:#475569;
  --shadow:0 4px 16px rgba(15,23,42,.06);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;font-size:15px;line-height:1.5}
h1,h2,h3{margin:0 0 12px}
h1{font-size:32px}
h2{font-size:20px;margin-top:32px}
button{font-family:inherit;font-size:14px;cursor:pointer;border-radius:8px;border:1px solid transparent;padding:8px 14px;transition:all .15s}
.ghost-btn{background:transparent;border:1px solid var(--border);color:var(--text)}
.ghost-btn:hover{background:var(--surface-2)}
.primary-btn{background:var(--primary);color:#fff;border-color:var(--primary)}
.primary-btn:hover{background:var(--primary-2)}
.danger-btn{background:var(--danger);color:#fff;border-color:var(--danger)}
.danger-btn:hover{filter:brightness(1.1)}

/* Top bar */
.topbar{display:flex;justify-content:space-between;align-items:center;padding:16px 32px;border-bottom:1px solid var(--border);background:var(--surface);position:sticky;top:0;z-index:10}
.brand{display:flex;align-items:center;gap:12px}
.logo{width:40px;height:40px;border-radius:10px;background:linear-gradient(135deg,var(--primary),var(--accent));display:flex;align-items:center;justify-content:center;font-weight:700;color:#fff;font-size:16px}
.brand-title{font-weight:700;font-size:16px}
.brand-sub{color:var(--muted);font-size:12px}
.topbar-right{display:flex;gap:8px}

/* Screens */
main{max-width:1200px;margin:0 auto;padding:24px 32px}
.screen{display:none}
.screen.active{display:block}
.hidden{display:none !important}
.muted{color:var(--muted)}

/* Hero */
.hero{background:linear-gradient(135deg,rgba(59,130,246,.15),rgba(139,92,246,.15));border:1px solid var(--border);border-radius:var(--radius);padding:32px;margin-bottom:24px}
.hero h1{background:linear-gradient(135deg,#60a5fa,#a78bfa);-webkit-background-clip:text;background-clip:text;color:transparent;font-size:40px}
.hero-sub{color:var(--muted);max-width:720px;margin-bottom:20px}
.stat-row{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;max-width:600px}
.stat{background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:16px}
.stat-num{font-size:28px;font-weight:700;color:var(--primary)}
.stat-lbl{color:var(--muted);font-size:12px;text-transform:uppercase;letter-spacing:.5px}

/* Mode cards */
.mode-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:16px}
.mode-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px;cursor:pointer;transition:transform .15s,border-color .15s,box-shadow .15s}
.mode-card:hover{transform:translateY(-2px);border-color:var(--primary);box-shadow:var(--shadow)}
.mode-icon{font-size:28px;margin-bottom:8px}
.mode-title{font-weight:600;font-size:16px;margin-bottom:6px}
.mode-desc{color:var(--muted);font-size:13px;margin-bottom:12px;min-height:52px}
.mode-meta{font-size:12px;color:var(--primary);font-weight:500}

/* Blueprint */
.blueprint{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px}
.blueprint table{width:100%;border-collapse:collapse}
.blueprint th,.blueprint td{text-align:left;padding:10px 12px;border-bottom:1px solid var(--border);font-size:14px}
.blueprint th{color:var(--muted);font-weight:600;text-transform:uppercase;font-size:11px;letter-spacing:.5px}
.blueprint tfoot td{border-bottom:none}
.fine{color:var(--muted);font-size:13px;margin-top:12px}

/* Modal */
.modal{position:fixed;inset:0;background:rgba(0,0,0,.6);display:flex;align-items:center;justify-content:center;z-index:100}
.modal.hidden{display:none}
.modal-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:28px;max-width:520px;width:90%;position:relative;box-shadow:var(--shadow)}
.modal-close{position:absolute;top:12px;right:12px;background:transparent;border:none;color:var(--muted);font-size:20px;cursor:pointer}
.modal .form-row{margin-bottom:16px}
.modal label{display:block;font-size:13px;color:var(--muted);margin-bottom:6px}
.modal select,.modal input[type=number]{width:100%;padding:10px;background:var(--surface-2);border:1px solid var(--border);border-radius:8px;color:var(--text);font-size:14px}
.modal .checkbox-row{display:flex;align-items:center;gap:8px}
.modal .modal-actions{display:flex;gap:8px;justify-content:flex-end;margin-top:20px}

/* Exam */
.exam-topbar{display:flex;justify-content:space-between;align-items:center;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:14px 20px;margin-bottom:16px}
.exam-controls{display:flex;gap:8px;align-items:center}
.timer{font-family:'SF Mono',Menlo,Consolas,monospace;font-size:18px;font-weight:600;color:var(--primary);padding:6px 12px;background:var(--surface-2);border-radius:6px}
.timer.warn{color:var(--warn)}
.timer.danger{color:var(--danger)}

.exam-layout{display:grid;grid-template-columns:220px 1fr;gap:16px}
.navigator{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:16px;height:fit-content;position:sticky;top:88px;max-height:calc(100vh - 110px);overflow-y:auto}
.nav-title{font-weight:600;font-size:13px;margin-bottom:8px;text-transform:uppercase;color:var(--muted);letter-spacing:.5px}
.nav-legend{display:flex;flex-direction:column;gap:6px;margin-bottom:12px;font-size:11px;color:var(--muted)}
.nav-legend .dot{display:inline-block;width:10px;height:10px;border-radius:2px;margin-right:6px;vertical-align:middle}
.dot-answered{background:var(--primary)}
.dot-flagged{background:var(--warn)}
.dot-current{background:var(--accent)}
.nav-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:4px}
.nav-btn{width:100%;aspect-ratio:1;background:var(--surface-2);border:1px solid var(--border);border-radius:4px;color:var(--muted);font-size:11px;padding:0;cursor:pointer}
.nav-btn.answered{background:var(--primary);color:#fff;border-color:var(--primary)}
.nav-btn.flagged{background:var(--warn);color:#fff;border-color:var(--warn)}
.nav-btn.answered.flagged{background:linear-gradient(135deg,var(--primary) 50%,var(--warn) 50%);color:#fff}
.nav-btn.current{outline:2px solid var(--accent);outline-offset:2px}

.question-panel{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:24px 28px}
.qmeta{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px;flex-wrap:wrap;gap:8px}
.qmeta #qCounter{font-weight:600;color:var(--muted);font-size:13px;text-transform:uppercase;letter-spacing:.5px}
.badge{background:var(--surface-2);color:var(--primary);font-size:11px;padding:4px 10px;border-radius:99px;font-weight:500;border:1px solid var(--border)}
.qstem{font-size:16px;line-height:1.6;margin-bottom:20px;padding-bottom:16px;border-bottom:1px solid var(--border)}
.qoptions{display:flex;flex-direction:column;gap:8px;margin-bottom:16px}
.qopt{background:var(--surface-2);border:1px solid var(--border);border-radius:8px;padding:12px 16px;cursor:pointer;display:flex;gap:12px;align-items:flex-start;transition:all .1s}
.qopt:hover{border-color:var(--primary)}
.qopt.selected{border-color:var(--primary);background:rgba(59,130,246,.1)}
.qopt.correct{border-color:var(--success);background:rgba(16,185,129,.12)}
.qopt.incorrect{border-color:var(--danger);background:rgba(239,68,68,.12)}
.qopt-letter{width:26px;height:26px;flex:0 0 26px;border-radius:50%;background:var(--surface);border:1px solid var(--border);display:flex;align-items:center;justify-content:center;font-weight:600;font-size:13px}
.qopt.selected .qopt-letter{background:var(--primary);color:#fff;border-color:var(--primary)}
.qopt.correct .qopt-letter{background:var(--success);color:#fff;border-color:var(--success)}
.qopt.incorrect .qopt-letter{background:var(--danger);color:#fff;border-color:var(--danger)}

.qfeedback{background:var(--surface-2);border-left:3px solid var(--primary);border-radius:6px;padding:14px 16px;margin-bottom:16px;font-size:14px}
.qfeedback.correct{border-left-color:var(--success)}
.qfeedback.incorrect{border-left-color:var(--danger)}
.qfeedback-status{font-weight:600;margin-bottom:6px}
.qfeedback .status-ok{color:var(--success)}
.qfeedback .status-bad{color:var(--danger)}
.qfeedback-ref{color:var(--muted);font-size:12px;margin-top:6px}

.qnav{display:flex;justify-content:space-between;gap:8px}

/* Results */
.results-header{display:flex;justify-content:space-between;align-items:flex-start;margin-bottom:24px;flex-wrap:wrap;gap:12px}
.verdict{font-size:24px;font-weight:700;padding:12px 24px;border-radius:12px}
.verdict.pass{background:rgba(16,185,129,.15);color:var(--success);border:1px solid var(--success)}
.verdict.fail{background:rgba(239,68,68,.15);color:var(--danger);border:1px solid var(--danger)}
.score-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:16px;margin-bottom:24px}
.score-box{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px;text-align:center}
.score-num{font-size:32px;font-weight:700;color:var(--primary)}
.score-lbl{color:var(--muted);font-size:12px;text-transform:uppercase;letter-spacing:.5px;margin-top:4px}
.domain-bars{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px;margin-bottom:24px}
.domain-bar{margin-bottom:14px}
.domain-bar:last-child{margin-bottom:0}
.domain-bar-header{display:flex;justify-content:space-between;margin-bottom:4px;font-size:13px}
.bar-track{height:8px;background:var(--surface-2);border-radius:4px;overflow:hidden}
.bar-fill{height:100%;background:linear-gradient(90deg,var(--primary),var(--accent));border-radius:4px;transition:width .5s}
.bar-fill.low{background:linear-gradient(90deg,var(--danger),var(--warn))}
.bar-fill.mid{background:linear-gradient(90deg,var(--warn),var(--primary))}

.review-filter{display:flex;gap:8px;margin-bottom:12px;flex-wrap:wrap}
.chip{background:transparent;border:1px solid var(--border);color:var(--muted);border-radius:99px;padding:6px 14px;font-size:13px;cursor:pointer}
.chip.active{background:var(--primary);color:#fff;border-color:var(--primary)}
.review-list{display:flex;flex-direction:column;gap:12px}
.review-item{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:16px}
.review-item.correct{border-left:4px solid var(--success)}
.review-item.incorrect{border-left:4px solid var(--danger)}
.review-item.unanswered{border-left:4px solid var(--muted)}
.review-item-header{display:flex;justify-content:space-between;margin-bottom:8px;font-size:12px;color:var(--muted)}
.review-item-stem{margin-bottom:12px;font-weight:500}
.review-item-opt{padding:6px 10px;border-radius:6px;margin-bottom:4px;font-size:13px;display:flex;gap:8px}
.review-item-opt.your-correct{background:rgba(16,185,129,.15)}
.review-item-opt.your-wrong{background:rgba(239,68,68,.15)}
.review-item-opt.correct-answer{background:rgba(16,185,129,.08);border:1px dashed var(--success)}
.review-item-expl{color:var(--muted);font-size:13px;margin-top:8px;padding:8px 10px;background:var(--surface-2);border-radius:6px}

.results-actions{margin-top:32px;display:flex;gap:8px;justify-content:center}

/* History */
.history-list{display:flex;flex-direction:column;gap:8px}
.history-item{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:16px;display:grid;grid-template-columns:1fr auto auto auto auto;gap:16px;align-items:center;font-size:14px}
.history-item .h-mode{font-weight:600}
.history-item .h-score{font-weight:700;color:var(--primary)}
.history-item .h-verdict.pass{color:var(--success);font-weight:600}
.history-item .h-verdict.fail{color:var(--danger);font-weight:600}

/* Footer */
.footer{text-align:center;color:var(--muted);font-size:12px;padding:24px;border-top:1px solid var(--border);margin-top:40px}

/* ===== Catalog ===== */
.brand{background:transparent;border:none;padding:0;display:flex;align-items:center;gap:12px;cursor:pointer;text-align:left;color:inherit}
.brand:hover .brand-title{color:var(--primary)}

.cat-group{margin-bottom:32px}
.cat-group h2{margin-bottom:16px;color:var(--muted);text-transform:uppercase;font-size:13px;letter-spacing:1px;font-weight:600}

.exam-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:16px}
.exam-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:18px;display:flex;gap:14px;align-items:flex-start;cursor:pointer;transition:transform .15s,border-color .15s,box-shadow .15s;position:relative;overflow:hidden}
.exam-card::before{content:'';position:absolute;left:0;top:0;bottom:0;width:4px;background:var(--exam-color,var(--primary))}
.exam-card:hover{transform:translateY(-2px);border-color:var(--exam-color,var(--primary));box-shadow:var(--shadow)}
.exam-card.coming-soon{cursor:not-allowed;opacity:.6}
.exam-card.coming-soon:hover{transform:none;border-color:var(--border);box-shadow:none}
.exam-icon{width:52px;height:52px;border-radius:10px;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:700;font-size:16px;flex:0 0 52px}
.exam-body{flex:1;min-width:0}
.exam-title{font-weight:700;font-size:18px;margin-bottom:2px}
.exam-fullname{font-size:13px;color:var(--muted);margin-bottom:6px;line-height:1.3}
.exam-tagline{font-size:12px;color:var(--muted);margin-bottom:10px;line-height:1.3;font-style:italic}
.exam-meta{display:flex;gap:6px;flex-wrap:wrap}
.exam-meta .chip{padding:3px 8px;font-size:11px;background:var(--surface-2);color:var(--text);border:1px solid var(--border);border-radius:99px;font-weight:500}
.exam-meta .chip-muted{background:transparent;color:var(--muted);border-style:dashed}
.exam-cta{color:var(--muted);font-size:20px;align-self:center;font-weight:300}
.exam-card:hover .exam-cta{color:var(--exam-color,var(--primary))}

/* ===== Dashboard ===== */
.dash-header{display:flex;gap:16px;align-items:center;margin-bottom:16px}
.dash-icon{width:64px;height:64px;border-radius:14px;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:700;font-size:22px;flex:0 0 64px}
.dash-header-text h1{margin:0 0 4px}
.dash-fullname{color:var(--muted);font-size:14px;margin-bottom:4px}
.dash-tagline{font-style:italic;font-size:13px}
.dash-description{color:var(--muted);font-size:14px;line-height:1.6;max-width:800px;margin-bottom:24px}

@media (max-width:900px){
  .exam-layout{grid-template-columns:1fr}
  .navigator{position:static;max-height:none}
  .nav-grid{grid-template-columns:repeat(10,1fr)}
  .topbar{padding:12px 16px}
  main{padding:16px}
  .exam-grid{grid-template-columns:1fr}
}