:root {
    --primary: #7f1d1d;
    --primary-dark: #6b1a1a;
    --primary-light: #991b1b;
    --bg: #f8f9fa;
    --bg-card: #ffffff;
    --bg-sidebar: #ffffff;
    --text: #1a1a2e;
    --text-secondary: #64748b;
    --border: #e2e8f0;
    --header-height: 60px;
    --sidebar-width: 280px;
    --shadow: 0 2px 8px rgba(0,0,0,0.08);
    --radius: 12px;
}

[data-theme="dark"] {
    --bg: #0f172a;
    --bg-card: #1e293b;
    --bg-sidebar: #1e293b;
    --text: #e2e8f0;
    --text-secondary: #94a3b8;
    --border: #334155;
    --shadow: 0 2px 8px rgba(0,0,0,0.3);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: var(--bg); color: var(--text); line-height: 1.7; transition: background 0.3s, color 0.3s; }

.header { display: flex; align-items: center; justify-content: space-between; height: var(--header-height); padding: 0 24px; background: var(--primary); color: white; position: sticky; top: 0; z-index: 100; }
.header-left { display: flex; align-items: center; gap: 12px; }
.header-center { flex: 1; max-width: 400px; margin: 0 24px; }
.header-right { display: flex; align-items: center; gap: 8px; }
.logo { font-size: 1.3rem; font-weight: 700; }
.logo-accent { color: #fbbf24; margin-left: 4px; }
.sidebar-toggle { display: none; background: none; border: none; color: white; font-size: 1.5rem; cursor: pointer; padding: 4px 8px; }
.btn-icon { background: none; border: none; color: white; font-size: 1.2rem; cursor: pointer; padding: 8px; border-radius: 8px; transition: background 0.2s; }
.btn-icon:hover { background: rgba(255,255,255,0.15); }

.global-progress { display: flex; align-items: center; gap: 12px; }
.global-progress-bar { flex: 1; height: 8px; background: rgba(255,255,255,0.2); border-radius: 4px; overflow: hidden; min-width: 120px; }
.global-progress-fill { height: 100%; background: #fbbf24; border-radius: 4px; transition: width 0.5s ease; }
.global-progress-text { font-size: 0.85rem; white-space: nowrap; }

.main-layout { display: flex; height: calc(100vh - var(--header-height)); }
.sidebar { width: var(--sidebar-width); background: var(--bg-sidebar); border-right: 1px solid var(--border); overflow-y: auto; padding: 16px 0; flex-shrink: 0; }
.sidebar-section { padding: 8px 16px; }
.sidebar-section-title { font-size: 0.75rem; text-transform: uppercase; color: var(--text-secondary); font-weight: 600; margin-bottom: 8px; letter-spacing: 0.5px; }
.sidebar-item { display: flex; align-items: center; gap: 10px; padding: 10px 16px; cursor: pointer; border-radius: 8px; margin: 2px 8px; transition: all 0.2s; font-size: 0.9rem; color: var(--text); }
.sidebar-item:hover { background: var(--border); }
.sidebar-item.active { background: var(--primary); color: white; }
.sidebar-icon { font-size: 1.1rem; width: 24px; text-align: center; }
.sidebar-item .check-mark { margin-left: auto; font-size: 0.85rem; color: #22c55e; }
.dashboard-link { font-weight: 600; }

.content { flex: 1; overflow-y: auto; padding: 32px; max-width: 900px; margin: 0 auto; }

.dashboard-hero { background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: white; border-radius: var(--radius); padding: 40px; margin-bottom: 32px; text-align: center; }
.dashboard-hero h2 { font-size: 1.8rem; margin-bottom: 12px; }
.dashboard-hero p { opacity: 0.9; font-size: 1.05rem; }
.dashboard-stats { display: flex; justify-content: center; gap: 32px; margin-top: 24px; }
.dashboard-stat { text-align: center; }
.dashboard-stat-value { font-size: 2rem; font-weight: 700; }
.dashboard-stat-label { font-size: 0.85rem; opacity: 0.8; }

.dashboard-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 20px; }
.level-card { background: var(--bg-card); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); cursor: pointer; transition: all 0.3s; border-left: 4px solid var(--primary); position: relative; overflow: hidden; }
.level-card:hover { transform: translateY(-3px); box-shadow: 0 8px 25px rgba(0,0,0,0.12); }
.level-card-header { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 12px; }
.level-card-number { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; padding: 4px 10px; border-radius: 20px; color: white; }
.level-card-status { font-size: 0.8rem; color: var(--text-secondary); }
.level-card h3 { font-size: 1.05rem; margin-bottom: 8px; }
.level-card p { font-size: 0.85rem; color: var(--text-secondary); }
.level-card-progress { margin-top: 12px; height: 4px; background: var(--border); border-radius: 2px; overflow: hidden; }
.level-card-progress-fill { height: 100%; border-radius: 2px; transition: width 0.5s; }

.level-1 .level-card-number, .level-1 .level-card-progress-fill { background: #dc2626; }
.level-2 .level-card-number, .level-2 .level-card-progress-fill { background: #ea580c; }
.level-3 .level-card-number, .level-3 .level-card-progress-fill { background: #d97706; }
.level-4 .level-card-number, .level-4 .level-card-progress-fill { background: #ca8a04; }
.level-5 .level-card-number, .level-5 .level-card-progress-fill { background: #65a30d; }
.level-6 .level-card-number, .level-6 .level-card-progress-fill { background: #16a34a; }
.level-7 .level-card-number, .level-7 .level-card-progress-fill { background: #0d9488; }
.level-8 .level-card-number, .level-8 .level-card-progress-fill { background: #0891b2; }
.level-9 .level-card-number, .level-9 .level-card-progress-fill { background: #2563eb; }
.level-10 .level-card-number, .level-10 .level-card-progress-fill { background: #7c3aed; }
.level-11 .level-card-number, .level-11 .level-card-progress-fill { background: #9333ea; }
.level-12 .level-card-number, .level-12 .level-card-progress-fill { background: #c026d3; }

.module-header { margin-bottom: 32px; }
.module-header-top { display: flex; align-items: center; gap: 12px; margin-bottom: 8px; }
.module-back { background: none; border: none; color: var(--primary); cursor: pointer; font-size: 1.5rem; padding: 4px; }
.module-badge { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; padding: 4px 12px; border-radius: 20px; color: white; }
.module-header h2 { font-size: 1.5rem; margin-bottom: 4px; }
.module-header p { color: var(--text-secondary); }

.module-body { background: var(--bg-card); border-radius: var(--radius); padding: 32px; box-shadow: var(--shadow); margin-bottom: 24px; }
.module-body h3 { color: var(--primary); margin: 24px 0 12px 0; font-size: 1.15rem; }
.module-body h3:first-child { margin-top: 0; }
.module-body p { margin-bottom: 12px; }
.module-body ul, .module-body ol { margin: 12px 0; padding-left: 24px; }
.module-body li { margin-bottom: 6px; }
.module-body table { width: 100%; border-collapse: collapse; margin: 16px 0; }
.module-body th, .module-body td { border: 1px solid var(--border); padding: 10px 14px; text-align: left; font-size: 0.9rem; }
.module-body th { background: var(--primary); color: white; font-weight: 600; }
.module-body tr:nth-child(even) { background: rgba(0,0,0,0.02); }
[data-theme="dark"] .module-body tr:nth-child(even) { background: rgba(255,255,255,0.02); }
.module-body .highlight-box { background: linear-gradient(135deg, rgba(127,29,29,0.08), rgba(127,29,29,0.03)); border-left: 4px solid var(--primary); padding: 16px 20px; border-radius: 0 8px 8px 0; margin: 16px 0; }
[data-theme="dark"] .module-body .highlight-box { background: linear-gradient(135deg, rgba(127,29,29,0.2), rgba(127,29,29,0.1)); }

.module-nav { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-top: 24px; }
.btn { padding: 10px 24px; border-radius: 8px; border: none; cursor: pointer; font-size: 0.95rem; font-weight: 600; transition: all 0.2s; }
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary { background: var(--border); color: var(--text); }
.btn-secondary:hover { background: #cbd5e1; }
.btn-quiz { background: linear-gradient(135deg, var(--primary), var(--primary-light)); color: white; padding: 12px 32px; font-size: 1rem; }
.btn-quiz:hover { transform: translateY(-1px); box-shadow: 0 4px 12px rgba(127,29,29,0.3); }

.quiz-container { background: var(--bg-card); border-radius: var(--radius); padding: 32px; box-shadow: var(--shadow); }
.quiz-header { text-align: center; margin-bottom: 32px; }
.quiz-header h2 { font-size: 1.3rem; }
.quiz-progress { display: flex; justify-content: center; gap: 8px; margin-top: 16px; }
.quiz-dot { width: 12px; height: 12px; border-radius: 50%; background: var(--border); transition: all 0.3s; }
.quiz-dot.active { background: var(--primary); transform: scale(1.2); }
.quiz-dot.answered { background: #22c55e; }
.quiz-dot.wrong { background: #ef4444; }
.quiz-question { margin-bottom: 24px; }
.quiz-question h3 { font-size: 1.1rem; margin-bottom: 16px; line-height: 1.6; }
.quiz-options { display: flex; flex-direction: column; gap: 10px; }
.quiz-option { padding: 14px 18px; border: 2px solid var(--border); border-radius: 8px; cursor: pointer; transition: all 0.2s; font-size: 0.95rem; text-align: left; background: var(--bg-card); color: var(--text); }
.quiz-option:hover { border-color: var(--primary); background: rgba(127,29,29,0.05); }
.quiz-option.selected { border-color: var(--primary); background: rgba(127,29,29,0.1); }
.quiz-option.correct { border-color: #22c55e; background: rgba(34,197,94,0.1); }
.quiz-option.incorrect { border-color: #ef4444; background: rgba(239,68,68,0.1); }
.quiz-option:disabled { cursor: default; }
.quiz-explanation { margin-top: 16px; padding: 16px; background: rgba(127,29,29,0.05); border-radius: 8px; border-left: 4px solid var(--primary); font-size: 0.9rem; }
[data-theme="dark"] .quiz-explanation { background: rgba(127,29,29,0.15); }
.quiz-actions { text-align: center; margin-top: 24px; }

.modal-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); display: flex; align-items: center; justify-content: center; z-index: 200; backdrop-filter: blur(4px); }
.modal { background: var(--bg-card); border-radius: var(--radius); padding: 32px; max-width: 480px; width: 90%; text-align: center; box-shadow: 0 20px 60px rgba(0,0,0,0.2); }
.modal h2 { font-size: 1.5rem; margin-bottom: 8px; }
.modal .score { font-size: 3rem; font-weight: 700; color: var(--primary); margin: 16px 0; }
.modal .score-label { color: var(--text-secondary); margin-bottom: 24px; }
.modal .btn { margin: 4px; }

.fade-in { animation: fadeIn 0.3s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #94a3b8; }