:root{--bg-main: #0B0F19;--bg-card: rgba(17, 24, 39, .75);--bg-card-hover: rgba(30, 41, 59, .85);--bg-card-solid: #111827;--bg-surface: #1E293B;--border-color: rgba(255, 255, 255, .08);--border-highlight: rgba(99, 102, 241, .3);--text-primary: #F8FAFC;--text-secondary: #94A3B8;--text-muted: #64748B;--accent-primary: #6366F1;--accent-primary-hover: #4F46E5;--accent-glow: rgba(99, 102, 241, .25);--accent-teal: #0EA5E9;--accent-emerald: #10B981;--accent-emerald-glow: rgba(16, 185, 129, .25);--status-correct: #10B981;--status-correct-bg: rgba(16, 185, 129, .12);--status-correct-border: rgba(16, 185, 129, .4);--status-incorrect: #EF4444;--status-incorrect-bg: rgba(239, 68, 68, .12);--status-incorrect-border: rgba(239, 68, 68, .4);--status-warning: #F59E0B;--status-warning-bg: rgba(245, 158, 11, .12);--radius-sm: 8px;--radius-md: 12px;--radius-lg: 16px;--radius-xl: 24px;--shadow-card: 0 10px 25px -5px rgba(0, 0, 0, .5), 0 8px 10px -6px rgba(0, 0, 0, .5);--shadow-glow: 0 0 20px rgba(99, 102, 241, .2);--font-family: "Plus Jakarta Sans", system-ui, -apple-system, sans-serif;--font-heading: "Outfit", system-ui, -apple-system, sans-serif;--transition-fast: .15s cubic-bezier(.4, 0, .2, 1);--transition-normal: .25s cubic-bezier(.4, 0, .2, 1)}[data-theme=light]{--bg-main: #F8FAFC;--bg-card: rgba(255, 255, 255, .85);--bg-card-hover: rgba(241, 245, 249, .95);--bg-card-solid: #FFFFFF;--bg-surface: #F1F5F9;--border-color: rgba(0, 0, 0, .08);--border-highlight: rgba(99, 102, 241, .4);--text-primary: #0F172A;--text-secondary: #475569;--text-muted: #94A3B8;--accent-glow: rgba(99, 102, 241, .15);--shadow-card: 0 10px 25px -5px rgba(0, 0, 0, .05), 0 8px 10px -6px rgba(0, 0, 0, .02)}*{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-family);background-color:var(--bg-main);color:var(--text-primary);line-height:1.6;min-height:100vh;-webkit-font-smoothing:antialiased;background-image:radial-gradient(at 0% 0%,rgba(99,102,241,.08) 0px,transparent 50%),radial-gradient(at 100% 100%,rgba(14,165,233,.06) 0px,transparent 50%);background-attachment:fixed}h1,h2,h3,h4,h5,h6{font-family:var(--font-heading);letter-spacing:-.02em;font-weight:700}button{font-family:var(--font-family);cursor:pointer;border:none;background:none}.glass-panel{background:var(--bg-card);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border:1px solid var(--border-color);border-radius:var(--radius-lg);box-shadow:var(--shadow-card)}.app-container{max-width:1200px;margin:0 auto;padding:0 1.25rem 3rem}.navbar{display:flex;align-items:center;justify-content:space-between;padding:1.25rem 0;margin-bottom:2rem;border-bottom:1px solid var(--border-color)}.brand{display:flex;align-items:center;gap:.75rem;text-decoration:none;color:var(--text-primary)}.brand-icon{width:42px;height:42px;background:linear-gradient(135deg,#6366f1,#3b82f6);border-radius:var(--radius-md);display:flex;align-items:center;justify-content:center;color:#fff;box-shadow:0 4px 14px #6366f166}.brand-title{font-size:1.25rem;font-weight:800;display:flex;flex-direction:column;line-height:1.2}.brand-subtitle{font-size:.75rem;color:var(--text-secondary);font-weight:500}.nav-links{display:flex;align-items:center;gap:.5rem}.nav-btn{display:flex;align-items:center;gap:.5rem;padding:.5rem 1rem;border-radius:var(--radius-md);color:var(--text-secondary);font-size:.9rem;font-weight:600;transition:all var(--transition-fast)}.nav-btn:hover,.nav-btn.active{color:var(--text-primary);background:var(--bg-surface)}.theme-toggle{padding:.5rem;border-radius:var(--radius-md);color:var(--text-secondary);transition:all var(--transition-fast)}.theme-toggle:hover{color:var(--text-primary);background:var(--bg-surface)}.language-select{padding:.5rem .75rem;border-radius:var(--radius-md);border:1px solid var(--border-color);background:var(--bg-surface);color:var(--text-primary);font-size:.85rem;font-weight:500;cursor:pointer;transition:all var(--transition-fast)}.language-select:hover{border-color:var(--text-secondary)}.badge{display:inline-flex;align-items:center;gap:.35rem;padding:.25rem .65rem;border-radius:9999px;font-size:.75rem;font-weight:600;line-height:1}.badge-indigo{background:#6366f126;color:#818cf8;border:1px solid rgba(99,102,241,.3)}.badge-amber{background:var(--status-warning-bg);color:var(--status-warning);border:1px solid rgba(245,158,11,.3)}.badge-emerald{background:var(--status-correct-bg);color:var(--status-correct);border:1px solid var(--status-correct-border)}.stats-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:1.25rem;margin-bottom:2.5rem}.stat-card{padding:1.5rem;display:flex;align-items:center;gap:1.25rem;transition:transform var(--transition-fast)}.stat-card:hover{transform:translateY(-2px)}.stat-icon-wrapper{width:52px;height:52px;border-radius:var(--radius-md);display:flex;align-items:center;justify-content:center;flex-shrink:0}.stat-val{font-size:1.75rem;font-weight:800;line-height:1.1;font-family:var(--font-heading)}.stat-lbl{font-size:.85rem;color:var(--text-secondary)}.section-title{font-size:1.35rem;margin-bottom:1.25rem;display:flex;align-items:center;justify-content:space-between}.categories-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:1.25rem;margin-bottom:2.5rem}.category-card{padding:1.5rem;border-radius:var(--radius-lg);display:flex;flex-direction:column;justify-content:space-between;gap:1.25rem;cursor:pointer;transition:all var(--transition-normal);position:relative;overflow:hidden}.category-card:before{content:"";position:absolute;top:0;left:0;width:4px;height:100%;background:var(--accent-primary);opacity:0;transition:opacity var(--transition-fast)}.category-card:hover{border-color:var(--border-highlight);background:var(--bg-card-hover);transform:translateY(-3px);box-shadow:0 12px 30px -10px #0006}.category-card:hover:before{opacity:1}.category-header{display:flex;align-items:flex-start;justify-content:space-between;gap:1rem}.category-title{font-size:1.1rem;font-weight:700;margin-bottom:.25rem}.category-desc{font-size:.85rem;color:var(--text-secondary)}.progress-bar-container{width:100%;height:8px;background:#ffffff14;border-radius:9999px;overflow:hidden;position:relative}.progress-bar-fill{height:100%;background:linear-gradient(90deg,#6366f1,#0ea5e9);border-radius:9999px;transition:width .5s ease-out}.progress-bar-fill.emerald{background:linear-gradient(90deg,#10b981,#34d399)}.progress-meta{display:flex;align-items:center;justify-content:space-between;font-size:.8rem;color:var(--text-secondary)}.revision-container{max-width:860px;margin:0 auto}.revision-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:1.25rem}.question-card{padding:2rem;margin-bottom:1.5rem}.question-meta{display:flex;align-items:center;justify-content:space-between;margin-bottom:1rem}.question-text{font-size:1.2rem;font-weight:600;line-height:1.6;margin-bottom:1.5rem;color:var(--text-primary)}.question-image-wrapper{margin:1.25rem 0 1.5rem;text-align:center;background:#0003;padding:1rem;border-radius:var(--radius-md);border:1px solid var(--border-color)}.question-image{max-width:100%;max-height:320px;object-fit:contain;border-radius:var(--radius-sm);transition:transform var(--transition-fast)}.question-image:hover{transform:scale(1.02)}.options-list{display:flex;flex-direction:column;gap:.85rem}.option-btn{display:flex;align-items:flex-start;gap:1rem;padding:1.1rem 1.25rem;width:100%;text-align:left;border-radius:var(--radius-md);background:var(--bg-surface);border:1.5px solid var(--border-color);color:var(--text-primary);font-size:1rem;font-weight:500;transition:all var(--transition-fast)}.option-btn:hover:not(:disabled){border-color:var(--border-highlight);background:var(--bg-card-hover);transform:translate(4px)}button:disabled,.btn-primary:disabled,.btn-secondary:disabled,.nav-btn:disabled{opacity:.45!important;cursor:not-allowed!important;pointer-events:none!important;transform:none!important;box-shadow:none!important}.option-index{width:28px;height:28px;border-radius:50%;background:#ffffff1a;display:flex;align-items:center;justify-content:center;font-size:.85rem;font-weight:700;flex-shrink:0}.option-btn.selected-correct{background:var(--status-correct-bg);border-color:var(--status-correct);color:var(--text-primary)}.option-btn.selected-correct .option-index{background:var(--status-correct);color:#fff}.option-btn.selected-incorrect{background:var(--status-incorrect-bg);border-color:var(--status-incorrect);color:var(--text-primary)}.option-btn.selected-incorrect .option-index{background:var(--status-incorrect);color:#fff}.option-btn.show-correct{border-color:var(--status-correct);background:#10b98114}.explanation-box{margin-top:1.5rem;padding:1.5rem;border-radius:var(--radius-md);background:#6366f10f;border:1px solid rgba(99,102,241,.2);animation:slideDown .3s ease-out}@keyframes slideDown{0%{opacity:0;transform:translateY(-8px)}to{opacity:1;transform:translateY(0)}}.explanation-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:.75rem}.explanation-title{font-size:.95rem;font-weight:700;display:flex;align-items:center;gap:.5rem;color:var(--accent-primary)}.explanation-content{font-size:.95rem;color:var(--text-primary);line-height:1.65}.revision-nav{display:flex;align-items:center;justify-content:space-between;gap:1rem;margin-top:1.5rem}.btn-primary{background:linear-gradient(135deg,#6366f1,#4f46e5);color:#fff;font-weight:600;padding:.75rem 1.5rem;border-radius:var(--radius-md);display:inline-flex;align-items:center;gap:.5rem;transition:all var(--transition-fast);box-shadow:0 4px 12px #6366f14d}.btn-primary:hover{transform:translateY(-1px);box-shadow:0 6px 18px #6366f166}.btn-secondary{background:var(--bg-surface);color:var(--text-primary);font-weight:600;padding:.75rem 1.25rem;border-radius:var(--radius-md);display:inline-flex;align-items:center;gap:.5rem;border:1px solid var(--border-color);transition:all var(--transition-fast)}.btn-secondary:hover{background:var(--bg-card-hover);border-color:var(--border-highlight)}.video-container{width:100%;border-radius:var(--radius-md);overflow:hidden;background:#000;margin-bottom:1.5rem;position:relative;aspect-ratio:16 / 9}.video-overlay-gate{position:absolute;top:0;right:0;bottom:0;left:0;background:#000000a6;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1rem;z-index:10;cursor:pointer}.video-play-btn{width:68px;height:68px;border-radius:50%;background:linear-gradient(135deg,#6366f1,#3b82f6);display:flex;align-items:center;justify-content:center;color:#fff;box-shadow:0 0 30px #6366f199;transition:transform var(--transition-fast)}.video-overlay-gate:hover .video-play-btn{transform:scale(1.1)}.video-element{width:100%;height:100%;object-fit:contain}.search-input{width:100%;padding:.75rem 1rem .75rem 2.75rem;border-radius:var(--radius-md);background:var(--bg-surface);border:1px solid var(--border-color);color:var(--text-primary);font-size:.95rem;outline:none;transition:border-color var(--transition-fast)}.search-input:focus{border-color:var(--accent-primary)}.search-wrapper{position:relative;margin-bottom:1.5rem}.search-icon{position:absolute;left:1rem;top:50%;transform:translateY(-50%);color:var(--text-muted)}