*{margin:0;padding:0;box-sizing:border-box}
:root{
    --bg:#0b0f19;--surface:#111827;--surface2:#1e293b;
    --primary:#3b82f6;--secondary:#8b5cf6;--success:#10b981;
    --text:#f1f5f9;--text2:#94a3b8;--warning:#f59e0b;
    --border:rgba(255,255,255,0.06);--border2:rgba(255,255,255,0.08);
    --footer:#080c14;--code:#0d1117;
}
body.light-mode{
    --bg:#f0f4f8;--surface:#ffffff;--surface2:#e2e8f0;
    --primary:#2563eb;--secondary:#7c3aed;--success:#059669;
    --text:#0f172a;--text2:#334155;--warning:#d97706;
    --border:rgba(0,0,0,0.10);--border2:rgba(0,0,0,0.12);
    --footer:#e2e8f0;--code:#1e293b;
}
body.light-mode .navbar{background:rgba(255,255,255,.92);border-bottom-color:rgba(0,0,0,.08)}
body.light-mode .mobile-menu{background:rgba(255,255,255,.98)}
body.light-mode .nav-logo{color:#0f172a}
body.light-mode .nav-links a{color:#334155}
body.light-mode .nav-links a:hover{background:rgba(0,0,0,.05);color:#0f172a}
body.light-mode .mobile-menu a{color:#334155}
body.light-mode .mobile-menu a:hover{background:rgba(0,0,0,.04);color:#0f172a}
body.light-mode .hero{background:#f0f4f8}
body.light-mode .hero::before{background:radial-gradient(circle,rgba(37,99,235,.08) 0%,transparent 70%)}
body.light-mode .hero::after{background-image:radial-gradient(rgba(0,0,0,.06) 1px,transparent 1px)}
body.light-mode .hero h1{background:linear-gradient(135deg,#0f172a 0%,#1e3a5f 100%);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
body.light-mode .hero-sub{color:#334155}
body.light-mode .hero-meta{color:#334155}
body.light-mode .section{background:#ffffff;border-color:rgba(0,0,0,0.08);box-shadow:0 1px 3px rgba(0,0,0,.06)}
body.light-mode .section-title{color:#0f172a}
body.light-mode .section-desc{color:#334155}
body.light-mode .overview-card{background:linear-gradient(135deg,#f8fafc,#ffffff);border-color:rgba(0,0,0,.08)}
body.light-mode .overview-card:hover{border-color:#2563eb}
body.light-mode .overview-card h3{color:#0f172a}
body.light-mode .overview-card p{color:#475569}
body.light-mode .info-box{background:#f8fafc;border-color:rgba(0,0,0,.08);border-left-color:#2563eb}
body.light-mode .info-box h3{color:#0f172a}
body.light-mode .info-box p,.light-mode .info-box li{color:#334155}
body.light-mode .dark-table th{background:#1e293b;color:#fff}
body.light-mode .dark-table td{color:#1e293b}
body.light-mode .dark-table tr:nth-child(even) td{background:rgba(0,0,0,.03)}
body.light-mode .dark-table tr:hover td{background:rgba(37,99,235,.04)}
body.light-mode .week-card{background:#ffffff;border-color:rgba(0,0,0,.08)}
body.light-mode .week-card:hover{border-color:rgba(37,99,235,.35)}
body.light-mode .week-card h3{color:#0f172a}
body.light-mode .week-badge{background:#dbeafe;color:#1d4ed8}
body.light-mode .timeline::before{background:#cbd5e1}
body.light-mode .expand-btn{border-color:rgba(0,0,0,.12);color:#334155}
body.light-mode .expand-btn:hover{border-color:#2563eb;color:#2563eb}
body.light-mode .footer{background:#e2e8f0;border-top-color:rgba(0,0,0,.08)}
body.light-mode .footer-cta h2{color:#0f172a}
body.light-mode .footer-cta>p{color:#334155}
body.light-mode .cta-points span{color:#334155}
body.light-mode .footer-contact{border-top-color:rgba(0,0,0,.08)}
body.light-mode .footer-contact h3{color:#0f172a}
body.light-mode .footer-contact p{color:#334155}
body.light-mode .footer-bottom{color:#475569;border-top-color:rgba(0,0,0,.08)}
body.light-mode .theme-toggle{color:#334155;border-color:rgba(0,0,0,.12)}
body.light-mode .theme-toggle:hover{border-color:#2563eb;color:#2563eb}
body.light-mode .scroll-top{background:#ffffff;border-color:rgba(0,0,0,.08);color:#334155}
body.light-mode .scroll-top:hover{border-color:#2563eb;color:#2563eb}
body.light-mode .toc{background:#ffffff;border-color:rgba(0,0,0,.08)}
body.light-mode .toc h4{color:#475569}
body.light-mode .toc-item{color:#475569}
body.light-mode .toc-item:hover{color:#0f172a;background:rgba(0,0,0,.03)}
body.light-mode .toc-item.active{color:#2563eb;border-left-color:#2563eb;background:rgba(37,99,235,.06)}
body.light-mode .code-block{background:#1e293b;color:#e2e8f0;border-color:rgba(0,0,0,.12)}
body.light-mode .copy-btn{background:#334155;color:#e2e8f0}
body.light-mode .quiz-box{background:#f8fafc;border-color:rgba(0,0,0,.08)}
body.light-mode .quiz-question{color:#0f172a}
body.light-mode .quiz-option{background:#fff;border-color:rgba(0,0,0,.08);color:#334155}
body.light-mode .quiz-option:hover{border-color:#2563eb;color:#0f172a}
body.light-mode .quiz-option.correct{background:rgba(5,150,105,.12);border-color:#059669;color:#047857}
body.light-mode .quiz-option.incorrect{background:rgba(220,38,38,.1);border-color:#dc2626;color:#dc2626}
body.light-mode .score-summary{background:#f8fafc;border-color:rgba(0,0,0,.08)}
html{scroll-behavior:smooth}
body{font-family:'Inter',sans-serif;background:var(--bg);color:var(--text);line-height:1.7;overflow-x:hidden}
a{color:var(--primary);text-decoration:none;transition:color .2s}
a:hover{color:#60a5fa}
ul{list-style:none;padding:0}
.navbar{position:fixed;top:0;left:0;right:0;background:rgba(11,15,25,.9);backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);border-bottom:1px solid var(--border);z-index:1000;padding:0 24px}
.nav-inner{max-width:1200px;margin:0 auto;display:flex;justify-content:space-between;align-items:center;height:64px}
.nav-logo{font-size:1.15rem;font-weight:700;color:var(--text);display:flex;align-items:center;gap:10px}
.nav-logo i{color:var(--primary);font-size:1.3rem}
.nav-links{display:flex;gap:8px}
.nav-links a{color:var(--text2);padding:8px 16px;border-radius:8px;font-size:.875rem;font-weight:500;transition:all .2s}
.nav-links a:hover{color:var(--text);background:rgba(255,255,255,.05)}
.theme-toggle{background:none;border:1px solid var(--border2);color:var(--text2);width:36px;height:36px;border-radius:8px;cursor:pointer;font-size:1rem;display:flex;align-items:center;justify-content:center;transition:all .2s;margin-left:4px}
.theme-toggle:hover{border-color:var(--primary);color:var(--primary)}
.hamburger{display:none;background:none;border:none;color:var(--text);font-size:1.25rem;cursor:pointer;padding:8px}
.mobile-menu{display:none;position:fixed;top:64px;left:0;right:0;background:rgba(11,15,25,.98);backdrop-filter:blur(20px);border-bottom:1px solid var(--border);padding:16px 24px;flex-direction:column;gap:4px}
.mobile-menu a{color:var(--text2);padding:12px 16px;border-radius:8px;font-size:.95rem;font-weight:500;display:block}
.mobile-menu a:hover{background:rgba(255,255,255,.05);color:var(--text)}
.mobile-menu.open{display:flex}
.hero{margin-top:64px;padding:100px 24px 80px;text-align:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;top:50%;left:50%;width:800px;height:800px;transform:translate(-50%,-50%);background:radial-gradient(circle,rgba(59,130,246,.08) 0%,transparent 70%);pointer-events:none}
.hero::after{content:'';position:absolute;inset:0;background-image:radial-gradient(rgba(255,255,255,.03) 1px,transparent 1px);background-size:32px 32px;pointer-events:none}
.hero-content{position:relative;z-index:1;max-width:800px;margin:0 auto}
.hero h1{font-size:3.5rem;font-weight:800;letter-spacing:-.02em;line-height:1.1;margin-bottom:20px;background:linear-gradient(135deg,var(--text) 0%,var(--text2) 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.hero-sub{font-size:1.25rem;color:var(--text2);margin-bottom:8px;font-weight:400}
.hero-meta{margin-top:28px;display:flex;align-items:center;justify-content:center;gap:8px;color:var(--text2);font-size:1rem;flex-wrap:wrap}
.hero-meta i{color:var(--primary)}
.hero-badges{margin-top:20px;display:flex;align-items:center;justify-content:center;gap:12px;flex-wrap:wrap}
.hero-badge{background:rgba(59,130,246,.15);color:var(--primary);padding:6px 16px;border-radius:20px;font-size:.85rem;font-weight:600}
.container{max-width:1200px;margin:0 auto;padding:0 24px}
.container.narrow{max-width:900px}
.section{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:48px;margin:32px 0}
.section-title{font-size:2rem;font-weight:700;margin-bottom:24px;display:flex;align-items:center;gap:12px}
.section-title::before{content:'';width:4px;height:32px;background:var(--primary);border-radius:2px;flex-shrink:0}
.section-title i{color:var(--primary);font-size:1.5rem}
.section-desc{font-size:1.125rem;color:var(--text2);line-height:1.8;margin-bottom:24px}
.subsection{margin:28px 0}
.subsection h3{font-size:1.25rem;font-weight:700;margin-bottom:12px;color:var(--text);display:flex;align-items:center;gap:8px}
.subsection h3 i{color:var(--primary);font-size:1rem}
.overview-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:20px;margin:28px 0}
.overview-card{background:linear-gradient(135deg,var(--surface2),var(--surface));border:1px solid var(--border2);border-radius:12px;padding:28px;transition:border-color .3s}
.overview-card:hover{border-color:var(--primary)}
.overview-card h3{font-size:1.125rem;font-weight:600;margin-bottom:10px;display:flex;align-items:center;gap:10px}
.overview-card h3 i{color:var(--primary);font-size:1.1rem}
.overview-card p{color:var(--text2);font-size:.95rem}
.info-box{background:var(--surface2);border:1px solid var(--border2);border-left:3px solid var(--primary);border-radius:8px;padding:24px;margin:20px 0}
.info-box.warning{border-left-color:var(--warning)}
.info-box.success{border-left-color:var(--success)}
.info-box.danger{border-left-color:#ef4444}
.info-box h3{font-size:1.1rem;font-weight:600;margin-bottom:10px;display:flex;align-items:center;gap:8px}
.info-box h3 i{color:var(--primary)}
.info-box.warning h3 i{color:var(--warning)}
.info-box.success h3 i{color:var(--success)}
.info-box.danger h3 i{color:#ef4444}
.info-box p,.info-box li{color:var(--text2);font-size:.95rem;line-height:1.8}
.info-box ul{padding-left:0}
.info-box li{padding:4px 0;display:flex;align-items:flex-start;gap:8px}
.info-box li i{color:var(--success);margin-top:5px;font-size:.8rem;flex-shrink:0}
.timeline{position:relative;padding:20px 0 0 40px}
.timeline::before{content:'';position:absolute;left:11px;top:0;bottom:0;width:2px;background:var(--surface2)}
.timeline-item{position:relative;margin-bottom:24px}
.timeline-item::before{content:'';position:absolute;left:-40px;top:20px;width:12px;height:12px;border-radius:50%;background:var(--primary);box-shadow:0 0 0 4px var(--bg),0 0 12px rgba(59,130,246,.3);z-index:1}
.week-card{background:var(--surface);border:1px solid var(--border2);border-radius:12px;padding:24px;transition:border-color .3s}
.week-card:hover{border-color:rgba(59,130,246,.3)}
.week-badge{display:inline-block;background:var(--surface2);color:var(--primary);padding:4px 14px;border-radius:20px;font-size:.8rem;font-weight:600;margin-bottom:12px}
.week-card h3{font-size:1.15rem;font-weight:600;display:flex;align-items:center;gap:10px}
.week-card h3 i{color:var(--primary);font-size:1rem}
.week-card p{color:var(--text2);font-size:.9rem;margin-top:8px}
.week-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:16px}
.start-btn{background:var(--success);color:#fff;border:none;padding:8px 20px;border-radius:8px;cursor:pointer;font-size:.85rem;font-weight:600;font-family:'Inter',sans-serif;text-decoration:none;display:inline-flex;align-items:center;gap:6px;transition:all .2s}
.start-btn:hover{background:#059669;color:#fff}
.start-btn i{font-size:.75rem}
.chapter-tag{display:inline-block;background:rgba(139,92,246,.15);color:#a78bfa;padding:2px 10px;border-radius:12px;font-size:.75rem;font-weight:600;margin-left:8px}
.code-block{background:var(--code);border:1px solid var(--border2);border-radius:8px;padding:20px;margin:14px 0;overflow-x:auto;font-family:'JetBrains Mono',monospace;font-size:.85rem;color:#e6edf3;line-height:1.6;position:relative;white-space:pre}
.copy-btn{position:absolute;top:10px;right:10px;background:var(--surface2);border:1px solid var(--border2);color:var(--text2);padding:4px 10px;border-radius:6px;cursor:pointer;font-size:.75rem;font-family:'Inter',sans-serif;transition:all .2s}
.copy-btn:hover{border-color:var(--primary);color:var(--primary)}
code{font-family:'JetBrains Mono',monospace;background:var(--surface2);padding:2px 6px;border-radius:4px;font-size:.85em;color:#a78bfa}
.dark-table{width:100%;border-collapse:collapse;margin:20px 0;border-radius:8px;overflow:hidden}
.dark-table th{background:var(--surface2);color:var(--text);padding:14px 18px;text-align:left;font-weight:600;font-size:.9rem;border-bottom:1px solid var(--border2)}
.dark-table td{padding:14px 18px;color:var(--text2);font-size:.9rem;border-bottom:1px solid var(--border)}
.dark-table tr:nth-child(even) td{background:rgba(255,255,255,.02)}
.two-col{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin:20px 0}
.quiz-box{background:var(--surface2);border:1px solid var(--border2);border-radius:12px;padding:24px;margin:20px 0}
.quiz-question{font-weight:600;color:var(--text);margin-bottom:14px;font-size:1rem}
.quiz-option{background:var(--surface);border:1px solid var(--border2);padding:12px 16px;margin:6px 0;border-radius:8px;cursor:pointer;transition:all .2s;color:var(--text2);font-size:.9rem}
.quiz-option:hover{border-color:var(--primary);color:var(--text)}
.quiz-option.correct{background:rgba(16,185,129,.12);border-color:var(--success);color:var(--success);cursor:default}
.quiz-option.incorrect{background:rgba(239,68,68,.1);border-color:#ef4444;color:#ef4444;cursor:default}
.quiz-explanation{display:none;margin-top:10px;padding:12px;background:rgba(59,130,246,.08);border-radius:8px;font-size:.88rem;color:var(--text2);border-left:3px solid var(--primary)}
.quiz-explanation.show{display:block}
.score-summary{background:var(--surface2);border:1px solid var(--border2);border-radius:12px;padding:20px;margin:24px 0;text-align:center}
.score-summary h4{font-size:1rem;font-weight:600;margin-bottom:8px}
.score-summary .score{font-size:2rem;font-weight:800;color:var(--primary)}
.footer{background:var(--footer);border-top:1px solid var(--border);margin-top:48px}
.footer-cta{text-align:center;padding:64px 24px 48px}
.footer-cta h2{font-size:2rem;font-weight:700;margin-bottom:16px}
.footer-cta h2 i{color:var(--primary)}
.footer-cta>p{color:var(--text2);font-size:1.15rem;margin-bottom:28px}
.cta-points{display:flex;flex-wrap:wrap;justify-content:center;gap:16px 32px;margin-bottom:40px}
.cta-points span{color:var(--text2);font-size:.95rem;display:flex;align-items:center;gap:6px}
.cta-points i{color:var(--success);font-size:.8rem}
.footer-contact{border-top:1px solid var(--border);padding:32px 24px;text-align:center}
.footer-contact h3{font-size:1.1rem;font-weight:600;margin-bottom:12px;display:flex;align-items:center;justify-content:center;gap:8px}
.footer-contact h3 i{color:var(--primary)}
.footer-contact p{color:var(--text2);font-size:.9rem;line-height:1.8}
.footer-bottom{border-top:1px solid var(--border);padding:20px 24px;text-align:center;color:var(--text2);font-size:.8rem}
.scroll-top{position:fixed;bottom:28px;right:28px;width:44px;height:44px;border-radius:10px;background:var(--surface);border:1px solid var(--border2);color:var(--text2);display:flex;align-items:center;justify-content:center;cursor:pointer;font-size:1rem;transition:all .2s;opacity:0;pointer-events:none;z-index:900}
.scroll-top.visible{opacity:1;pointer-events:auto}
.scroll-top:hover{border-color:var(--primary);color:var(--primary)}
.toc{position:fixed;right:24px;top:100px;background:var(--surface);border:1px solid var(--border2);border-radius:10px;padding:16px;width:200px;opacity:0;transform:translateX(20px);transition:all .3s;pointer-events:none;z-index:900}
.toc.visible{opacity:1;transform:translateX(0);pointer-events:auto}
.toc h4{font-size:.8rem;font-weight:600;color:var(--text2);text-transform:uppercase;letter-spacing:.05em;margin-bottom:12px}
.toc-item{display:block;padding:6px 12px;font-size:.825rem;color:var(--text2);border-left:2px solid transparent;margin:2px 0;border-radius:0 4px 4px 0;transition:all .2s;cursor:pointer}
.toc-item:hover{color:var(--text);background:rgba(255,255,255,.03)}
.toc-item.active{color:var(--primary);border-left-color:var(--primary);background:rgba(59,130,246,.05)}
.nav-btn{display:inline-flex;align-items:center;gap:8px;padding:10px 20px;border-radius:8px;font-size:.9rem;font-weight:600;transition:all .2s}
.nav-btn.prev{background:var(--surface2);color:var(--text2);border:1px solid var(--border2)}
.nav-btn.prev:hover{border-color:var(--primary);color:var(--primary)}
.nav-btn.next{background:var(--success);color:#fff}
.nav-btn.next:hover{background:#059669;color:#fff}
.page-nav{display:flex;justify-content:space-between;align-items:center;margin:40px 0 0}
.fade-up{opacity:0;transform:translateY(24px);transition:opacity .4s ease,transform .4s ease}
.fade-up.visible{opacity:1;transform:translateY(0)}
.kw{color:#ff7b72}.str{color:#a5d6ff}.cm{color:#8b949e}.num{color:#79c0ff}.fn{color:#d2a8ff}.type{color:#ffa657}
/* Exam Page Styles */
.exam-header{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:16px;margin-bottom:24px}
.exam-timer{display:flex;align-items:center;gap:8px;background:var(--surface2);border:1px solid var(--border2);padding:10px 20px;border-radius:10px;font-size:1.1rem;font-weight:700;font-family:'JetBrains Mono',monospace}
.exam-timer i{color:var(--primary)}
.exam-timer.warning{color:var(--warning);border-color:var(--warning)}
.exam-timer.danger{color:#ef4444;border-color:#ef4444;animation:pulse 1s infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.6}}
.exam-progress{font-size:.9rem;color:var(--text2)}
.exam-progress strong{color:var(--text)}
.exam-question{background:var(--surface);border:1px solid var(--border2);border-radius:12px;padding:28px;margin:16px 0;transition:border-color .3s}
.exam-question.answered{border-color:var(--primary)}
.exam-question.review-correct{border-color:var(--success);background:rgba(16,185,129,.04)}
.exam-question.review-incorrect{border-color:#ef4444;background:rgba(239,68,68,.04)}
.exam-q-header{display:flex;justify-content:space-between;align-items:flex-start;gap:12px;margin-bottom:16px}
.exam-q-number{background:var(--primary);color:#fff;width:32px;height:32px;border-radius:8px;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.85rem;flex-shrink:0}
.exam-q-text{font-weight:600;font-size:1rem;color:var(--text);flex:1;line-height:1.6}
.exam-q-status{font-size:.8rem;padding:4px 10px;border-radius:12px;font-weight:600;flex-shrink:0}
.exam-q-status.correct{background:rgba(16,185,129,.15);color:var(--success)}
.exam-q-status.incorrect{background:rgba(239,68,68,.15);color:#ef4444}
.exam-q-status.skipped{background:rgba(245,158,11,.15);color:var(--warning)}
.exam-option{background:var(--surface2);border:1px solid var(--border);padding:12px 16px;margin:6px 0;border-radius:8px;cursor:pointer;transition:all .2s;color:var(--text2);font-size:.9rem;display:flex;align-items:flex-start;gap:10px}
.exam-option:hover{border-color:var(--primary);color:var(--text)}
.exam-option.selected{border-color:var(--primary);background:rgba(59,130,246,.1);color:var(--text)}
.exam-option.review-correct{border-color:var(--success);background:rgba(16,185,129,.12);color:var(--success)}
.exam-option.review-incorrect{border-color:#ef4444;background:rgba(239,68,68,.1);color:#ef4444}
.exam-option.review-missed{border-color:var(--success);background:rgba(16,185,129,.06);color:var(--success)}
.exam-option-letter{background:var(--surface);border:1px solid var(--border2);width:28px;height:28px;border-radius:6px;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.8rem;flex-shrink:0}
.exam-option.selected .exam-option-letter{background:var(--primary);color:#fff;border-color:var(--primary)}
.exam-option.review-correct .exam-option-letter{background:var(--success);color:#fff;border-color:var(--success)}
.exam-option.review-incorrect .exam-option-letter{background:#ef4444;color:#fff;border-color:#ef4444}
.exam-explanation{display:none;margin-top:12px;padding:12px 16px;background:rgba(59,130,246,.08);border-radius:8px;font-size:.88rem;color:var(--text2);border-left:3px solid var(--primary);line-height:1.7}
.exam-explanation.show{display:block}
.exam-nav{display:flex;flex-wrap:wrap;gap:8px;margin:20px 0;justify-content:center}
.exam-nav-btn{width:40px;height:40px;border-radius:8px;border:1px solid var(--border2);background:var(--surface);color:var(--text2);display:flex;align-items:center;justify-content:center;cursor:pointer;font-weight:600;font-size:.85rem;transition:all .2s}
.exam-nav-btn:hover{border-color:var(--primary);color:var(--primary)}
.exam-nav-btn.answered{background:var(--primary);color:#fff;border-color:var(--primary)}
.exam-nav-btn.current{box-shadow:0 0 0 2px var(--primary);border-color:var(--primary)}
.exam-nav-btn.review-correct{background:var(--success);color:#fff;border-color:var(--success)}
.exam-nav-btn.review-incorrect{background:#ef4444;color:#fff;border-color:#ef4444}
.exam-actions{text-align:center;margin:32px 0}
.exam-submit{background:var(--success);color:#fff;border:none;padding:14px 40px;border-radius:10px;cursor:pointer;font-size:1rem;font-weight:700;font-family:'Inter',sans-serif;transition:all .2s;display:inline-flex;align-items:center;gap:8px}
.exam-submit:hover{background:#059669}
.exam-submit:disabled{opacity:.5;cursor:not-allowed}
.exam-result{background:var(--surface);border:1px solid var(--border2);border-radius:16px;padding:40px;text-align:center;margin:24px 0}
.exam-result h2{font-size:1.8rem;font-weight:800;margin-bottom:8px}
.exam-result .score-big{font-size:4rem;font-weight:800;margin:16px 0}
.exam-result .score-big.pass{color:var(--success)}
.exam-result .score-big.fail{color:#ef4444}
.exam-result-details{display:flex;justify-content:center;gap:32px;margin:24px 0;flex-wrap:wrap}
.exam-result-item{text-align:center}
.exam-result-item .num{font-size:1.5rem;font-weight:700}
.exam-result-item .label{font-size:.85rem;color:var(--text2);margin-top:4px}
.exam-result-item .num.green{color:var(--success)}
.exam-result-item .num.red{color:#ef4444}
.exam-result-item .num.orange{color:var(--warning)}
.review-btn{background:var(--primary);color:#fff;border:none;padding:12px 30px;border-radius:8px;cursor:pointer;font-size:.95rem;font-weight:600;font-family:'Inter',sans-serif;transition:all .2s;display:inline-flex;align-items:center;gap:8px;margin:8px}
.review-btn:hover{background:#2563eb}
.retake-btn{background:var(--surface2);color:var(--text);border:1px solid var(--border2);padding:12px 30px;border-radius:8px;cursor:pointer;font-size:.95rem;font-weight:600;font-family:'Inter',sans-serif;transition:all .2s;display:inline-flex;align-items:center;gap:8px;margin:8px}
.retake-btn:hover{border-color:var(--primary);color:var(--primary)}
body.light-mode .exam-question{background:#fff;border-color:rgba(0,0,0,.08)}
body.light-mode .exam-option{background:#f8fafc;border-color:rgba(0,0,0,.08);color:#334155}
body.light-mode .exam-option:hover{border-color:#2563eb;color:#0f172a}
body.light-mode .exam-option.selected{background:rgba(37,99,235,.08);border-color:#2563eb;color:#0f172a}
body.light-mode .exam-nav-btn{background:#fff;border-color:rgba(0,0,0,.08);color:#334155}
body.light-mode .exam-result{background:#fff;border-color:rgba(0,0,0,.08)}
body.light-mode .exam-timer{background:#f8fafc;border-color:rgba(0,0,0,.08)}
@media(max-width:1400px){.toc{display:none}}
@media(max-width:768px){
    .hero h1{font-size:2.2rem}
    .hero{padding:72px 20px 56px}
    .section{padding:28px 20px}
    .nav-links{display:none}
    .hamburger{display:block}
    .two-col{grid-template-columns:1fr}
    .overview-grid{grid-template-columns:1fr}
    .page-nav{flex-direction:column;gap:12px}
    .exam-header{flex-direction:column;align-items:stretch}
    .exam-result-details{gap:16px}
    .exam-result .score-big{font-size:3rem}
}