:root{--bg:#f0f4f8;--card-bg:#fff;--card-border:1px solid #00000012;--card-shadow:0 1px 4px #00000012, 0 4px 16px #0000000a;--card-radius:12px;--primary:#2563eb;--primary-hover:#1d4ed8;--primary-fg:#fff;--text:#1e293b;--text-muted:#64748b;--text-subtle:#94a3b8;--border:#e2e8f0;--input-bg:#fff;--option-bg:#fff;--option-hover:#f8fafc;--option-sel-bg:#eff6ff;--option-sel-bd:#2563eb;--correct-bg:#d1fae5;--correct-bd:#86efac;--correct-fg:#14532d;--wrong-bg:#fee2e2;--wrong-bd:#fca5a5;--wrong-fg:#7f1d1d;--expl-bg:#f0f9ff;--expl-bd:#38bdf8;--navbar-bg:#0f172a;--navbar-fg:#e2e8f0;--badge-radius:12px}[data-theme=markdown]{--bg:#f5f0e8;--card-bg:#fdfaf4;--card-border:1px solid #e0d5c5;--card-shadow:0 2px 8px #3c280a0f;--card-radius:10px;--primary:#8b5a2b;--primary-hover:#6d4420;--primary-fg:#fdf8f0;--text:#1e140a;--text-muted:#7a5c42;--text-subtle:#aa8a6a;--border:#e0d5c5;--input-bg:#fdfaf4;--option-bg:#fdfaf4;--option-hover:#f7f0e4;--option-sel-bg:#f2e4d0;--option-sel-bd:#8b5a2b;--correct-bg:#e8f5e8;--correct-bd:#8abf8a;--correct-fg:#1a4a1a;--wrong-bg:#fdecea;--wrong-bd:#d99090;--wrong-fg:#6b1a1a;--expl-bg:#f9f4ea;--expl-bd:#c4965a;--navbar-bg:#1e140a;--navbar-fg:#f0e8d8;--badge-radius:4px;--font-body:"Source Serif 4", Georgia, serif;--font-heading:"Inter", ui-sans-serif, system-ui, -apple-system, sans-serif;--font-ui:"Inter", system-ui, sans-serif}body[data-theme=markdown]{font-family:var(--font-ui);font-size:15.5px;line-height:1.7}[data-theme=markdown] .navbar .logo{color:#e0a84a;font-family:var(--font-heading);letter-spacing:-.02em}[data-theme=markdown] h1{font-family:var(--font-heading);letter-spacing:-.03em;font-weight:760;line-height:1.12}[data-theme=markdown] h2,[data-theme=markdown] .card h2{font-family:var(--font-heading);letter-spacing:-.02em;font-weight:680;line-height:1.2}[data-theme=markdown] h3{font-family:var(--font-ui);font-weight:600}[data-theme=markdown] .card h2{border-bottom:1px solid var(--border);margin-bottom:18px;padding-bottom:10px}[data-theme=markdown] .question-card{border-left:3px solid var(--primary)}[data-theme=markdown] .question-card h3{font-family:var(--font-body);color:var(--text);font-size:1.05rem;font-style:normal;font-weight:400;line-height:1.7}[data-theme=markdown] .option{border-radius:6px;font-size:.94rem}[data-theme=markdown] .option-letter{font-family:var(--font-ui);border-radius:3px;font-weight:600}[data-theme=markdown] .explanation{font-family:var(--font-body);border-left:3px solid var(--expl-bd);background:var(--expl-bg);color:var(--text-muted);font-size:.9rem;line-height:1.85}[data-theme=markdown] .btn{font-family:var(--font-ui);font-weight:500}[data-theme=markdown] .score-display .score-value{font-family:var(--font-heading);letter-spacing:-3px}*{box-sizing:border-box;margin:0;padding:0}body{background:var(--bg);color:var(--text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,sans-serif;line-height:1.6;transition:background .25s,color .25s;overflow-x:hidden}.container{max-width:1200px;margin:0 auto;padding:0 28px}.navbar{background:var(--navbar-bg);color:var(--navbar-fg);z-index:50;margin-bottom:32px;padding:0;position:sticky;top:0}.navbar .navbar-inner{justify-content:space-between;align-items:center;height:52px;display:flex}.navbar .logo{color:#60a5fa;letter-spacing:-.01em;white-space:nowrap;font-size:1.15rem;font-weight:700;text-decoration:none}[data-theme=markdown] .navbar .logo{color:#d4a96a}.nav-desktop{align-items:center;gap:4px;display:flex}.nav-mobile-controls{align-items:center;gap:8px;display:none}.navbar a{color:var(--navbar-fg);white-space:nowrap;border-radius:6px;padding:6px 10px;font-size:.83rem;text-decoration:none;transition:opacity .15s,background .15s}.navbar a:hover{background:#ffffff17;opacity:1!important}.navbar button{color:var(--navbar-fg);cursor:pointer;white-space:nowrap;background:0 0;border:1px solid #fff3;border-radius:6px;padding:5px 14px;font-family:inherit;font-size:.82rem}.card{background:var(--card-bg);border:var(--card-border);border-radius:var(--card-radius);box-shadow:var(--card-shadow);margin-bottom:16px;padding:28px}.card h2{color:var(--text);margin-bottom:16px;font-size:1.15rem;font-weight:600}.quiz-header-card .quiz-header-title,[data-theme=markdown] .quiz-header-card .quiz-header-title{font-family:var(--font-ui,"Inter", ui-sans-serif, system-ui, -apple-system, sans-serif);letter-spacing:-.025em;border:0;margin:0 0 2px;padding:0;font-size:clamp(.98rem,1.8vw,1.14rem);font-weight:720;line-height:1.18}.quiz-nav-controls{justify-content:space-between;align-items:center;gap:8px;margin-top:14px;display:flex}.quiz-nav-controls-top{background:color-mix(in srgb, var(--card-bg) 92%, 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solid var(--border);background:var(--input-bg);width:100%;color:var(--text);border-radius:8px;padding:9px 13px;font-family:inherit;font-size:.9rem}[data-theme=minimal] .form-group input,[data-theme=minimal] .form-group select,[data-theme=minimal] .form-group textarea{background:var(--input-bg);border-radius:6px}.form-group input:focus,.form-group select:focus,.form-group textarea:focus{border-color:var(--primary);outline:none;box-shadow:0 0 0 3px #2563eb1a}[data-theme=minimal] .form-group input:focus{box-shadow:0 0 0 2px #09090b18}.question-card{background:var(--card-bg);border:var(--card-border);border-left:4px solid var(--primary);border-radius:var(--card-radius);box-shadow:var(--card-shadow);margin-bottom:20px;padding:28px 28px 24px}.question-card h3{color:var(--text);margin-bottom:20px;font-size:1.05rem;font-weight:600;line-height:1.6}.question-image-preview{cursor:zoom-in;text-align:left;background:0 0;border:0;margin:10px 0;padding:0;display:block}.question-image-preview img{border:1px solid var(--border);border-radius:8px;max-width:100%;max-height:280px;display:block}.image-lightbox{z-index:1000;cursor:zoom-out;background:#0f172ad1;padding:24px;position:fixed;inset:0}.image-lightbox-viewport{cursor:default;justify-content:center;align-items:center;width:100%;height:100%;display:flex;overflow:auto}.image-lightbox img{cursor:default;border-radius:10px;display:block;box-shadow:0 24px 80px #00000059}.image-lightbox-controls{z-index:1001;color:#fff;background:#0f172ad1;border:1px solid #ffffff47;border-radius:999px;align-items:center;gap:8px;padding:7px 9px;display:flex;position:fixed;top:16px;left:50%;transform:translate(-50%)}.image-lightbox-controls button{color:#fff;cursor:pointer;background:#ffffff1f;border:1px solid #ffffff47;border-radius:999px;min-width:34px;height:30px;padding:0 10px}.image-lightbox-controls button:disabled{cursor:not-allowed;opacity:.45}.image-lightbox-controls span{text-align:center;min-width:48px;font-size:.86rem;font-weight:700}.image-lightbox-close{color:#fff;cursor:pointer;background:#0f172ab8;border:1px solid #ffffff59;border-radius:999px;width:40px;height:40px;font-size:1.5rem;line-height:1;position:fixed;top:16px;right:16px}.mynote-tab{z-index:45;position:fixed;bottom:18px;right:18px}.mynote-tab.dragging{-webkit-user-select:none;user-select:none}.mynote-tab-button{color:#fff;cursor:grab;letter-spacing:-.02em;touch-action:none;background:linear-gradient(135deg,#2563eb,#7c3aed);border:1px solid #2563eb38;border-radius:999px;padding:11px 18px;font-weight:800;box-shadow:0 16px 40px #2563eb47}.mynote-editor{background:linear-gradient(180deg, color-mix(in srgb, var(--card-bg) 96%, transparent), var(--card-bg)), radial-gradient(circle at top left, #2563eb1f, transparent 42%);border:1px solid #94a3b847;border-radius:18px;width:min(420px,100vw - 28px);overflow:hidden;box-shadow:0 24px 70px #0f172a3d}.mynote-editor-header{border-bottom:1px solid var(--border);justify-content:space-between;align-items:flex-start;gap:12px;padding:14px 16px 10px;display:flex}.mynote-drag-handle{cursor:grab;touch-action:none;-webkit-user-select:none;user-select:none}.mynote-tab.dragging .mynote-tab-button,.mynote-tab.dragging .mynote-drag-handle{cursor:grabbing}.mynote-title{letter-spacing:-.03em;color:var(--text);font-size:1rem;font-weight:850}.mynote-status{color:var(--text-muted);margin-top:2px;font-size:.75rem}.mynote-close,.mynote-modal-close{background:var(--border);color:var(--text);cursor:pointer;border:0;border-radius:999px}.mynote-close{padding:6px 10px;font-size:.76rem}.mynote-error{color:var(--wrong-fg);margin:10px 16px 0;font-size:.8rem}.mynote-editor textarea{resize:vertical;width:100%;min-height:260px;color:var(--text);font:inherit;background:0 0;border:0;outline:0;padding:16px;line-height:1.65}.mynote-card{border-left:4px solid 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.option-letter{background:var(--primary);color:#fff}.option.correct .option-letter{color:#fff;background:#16a34a}.option.incorrect .option-letter{color:#fff;background:#dc2626}.explanation{background:var(--expl-bg);border-left:3px solid var(--expl-bd);color:var(--text-muted);white-space:pre-line;border-radius:8px;margin-top:20px;padding:18px 20px;font-size:.875rem;line-height:1.75}.explanation strong{color:var(--text);font-weight:600}.review-card{background:var(--card-bg);border:var(--card-border);border-radius:var(--card-radius);box-shadow:var(--card-shadow);border-left:4px solid var(--border);margin-bottom:20px;padding:28px 28px 24px}.review-card.correct-card{border-left-color:#22c55e}.review-card.wrong-card{border-left-color:#ef4444}.review-card.skipped-card{border-left-color:var(--text-subtle)}.badge{border-radius:var(--badge-radius);padding:3px 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.navbar-inner{height:48px}.nav-desktop{display:none}.nav-mobile-controls{display:flex}.quiz-sidebar{display:none}.quiz-nav-toggle{display:inline-flex}.quiz-nav-controls{gap:6px}.quiz-nav-controls .btn{flex:1;justify-content:center;padding-left:10px;padding-right:10px}.quiz-nav-controls .quiz-nav-toggle{flex:none}.manual-highlight-toolbar{z-index:5;border:1px solid var(--border);grid-template-columns:auto;gap:8px;width:100%;margin-top:4px;display:grid;position:sticky;top:54px;box-shadow:0 8px 20px #0f172a14}.manual-highlight-toolbar .btn{white-space:normal;justify-content:center;min-height:36px}.mynote-tab{bottom:12px;right:12px}.mynote-tab.open{left:10px}.mynote-editor textarea{min-height:220px}.mynote-card{flex-direction:column;align-items:stretch}.mynote-card .btn{justify-content:center}}.lesson-content h1,.lesson-content h2,.lesson-content h3,.lesson-content h4{margin-top:1.2em;margin-bottom:.5em}.lesson-content h2{border-bottom:1px solid 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