:root {
    --primary: #667eea;
    --secondary: #764ba2;
    --success: #4CAF50;
    --warning: #FF9800;
    --danger: #F44336;
    --light-gray: #f8f9fa;
    --border-gray: #e8eaed;
    --text-dark: #333;
    --text-light: #666;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);
    --transition: all 0.2s ease;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background: var(--light-gray); color: var(--text-dark); line-height: 1.6; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.alert { padding: 15px 20px; border-radius: 5px; margin-bottom: 20px; }
.alert-warning { background: rgba(255,152,0,0.1); border-left: 4px solid #FF9800; color: #e65100; }
.alert-danger { background: rgba(244,67,54,0.1); border-left: 4px solid #F44336; color: #c62828; }
.alert-success { background: rgba(76,175,80,0.1); border-left: 4px solid #4CAF50; color: #2e7d32; }
.btn { display: inline-block; padding: 12px 24px; border: none; border-radius: 5px; font-weight: 600; cursor: pointer; transition: var(--transition); text-decoration: none; font-size: 1em; }
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--secondary); transform: translateY(-2px); }
.btn-small { padding: 8px 16px; background: var(--primary); color: white; border-radius: 5px; font-size: 0.9em; text-decoration: none; }
.btn-small:hover { background: var(--secondary); }
.btn-disabled { background: #ccc; color: #999; cursor: not-allowed; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; margin-bottom: 8px; font-weight: 600; }
.form-group input, .form-group select, .form-group textarea { width: 100%; padding: 12px; border: 1px solid var(--border-gray); border-radius: 5px; font-size: 1em; font-family: inherit; }
.form-group input:focus, .form-group select:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(102,126,234,0.1); }
.modal { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); z-index: 1000; align-items: center; justify-content: center; }
.modal.active { display: flex; }
.modal-content { position: relative; background: white; padding: 40px; border-radius: 10px; max-width: 500px; width: 90%; box-shadow: 0 5px 20px rgba(0,0,0,0.3); max-height: 90vh; overflow-y: auto; }
.modal-close { position: absolute; top: 15px; right: 15px; background: none; border: none; font-size: 1.5em; cursor: pointer; color: #999; }
.cbse-dashboard { background: var(--light-gray); min-height: 100vh; }
.dashboard-header { background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: white; padding: 40px 0; margin-bottom: 40px; }
.dashboard-header h1 { font-size: 2em; font-weight: 700; }
.class-info { margin: 10px 0 20px; opacity: 0.9; }
.subscription-badge { display: inline-block; padding: 10px 20px; border-radius: 20px; font-size: 0.9em; font-weight: 600; margin-top: 15px; }
.subscription-badge.success { background: rgba(76,175,80,0.3); color: #fff; }
.subscription-badge.warning { background: rgba(255,152,0,0.3); color: #fff; }
.subjects-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; margin-bottom: 40px; }
.subject-card { background: white; padding: 20px; border-radius: 8px; box-shadow: var(--shadow); transition: var(--transition); }
.subject-card:hover { transform: translateY(-5px); box-shadow: 0 5px 15px rgba(0,0,0,0.2); }
.subject-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 15px; }
.progress-badge { background: #e8eaed; padding: 5px 12px; border-radius: 12px; font-size: 0.85em; font-weight: 600; }
.progress-bar { height: 6px; background: #e8eaed; border-radius: 3px; overflow: hidden; margin-bottom: 15px; }
.progress-fill { height: 100%; transition: width 0.3s ease; }
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 16px; margin: 30px 0; }
.stat-card { background: white; padding: 20px; border-radius: 8px; box-shadow: var(--shadow); text-align: center; }
.stat-label { display: block; font-size: 0.85em; color: var(--text-light); margin-bottom: 8px; }
.stat-value { display: block; font-size: 1.8em; font-weight: 700; color: var(--primary); }
.cbse-class-selector { display: flex; gap: 12px; flex-wrap: wrap; }
.class-pill { padding: 12px 24px; border-radius: 20px; color: white; font-weight: 600; text-decoration: none; }
.cbse-chapters-container { max-width: 900px; margin: 40px auto; }
.chapters-list { display: flex; flex-direction: column; gap: 15px; }
.chapter-item { display: flex; align-items: center; background: white; padding: 20px; border-radius: 8px; box-shadow: var(--shadow); border-left: 5px solid #e8eaed; transition: var(--transition); }
.chapter-item.locked { opacity: 0.7; background: #f5f5f5; }
.chapter-item.accessible { border-left-color: var(--primary); }
.chapter-number { display: flex; align-items: center; justify-content: center; width: 50px; height: 50px; background: var(--primary); color: white; border-radius: 50%; font-weight: 700; font-size: 1.2em; margin-right: 20px; flex-shrink: 0; }
.chapter-info { flex: 1; }
.status-badge { display: inline-block; padding: 5px 12px; border-radius: 12px; font-size: 0.85em; font-weight: 600; }
.status-badge.complete { background: rgba(76,175,80,0.2); color: #2e7d32; }
.status-badge.in-progress { background: rgba(255,152,0,0.2); color: #e65100; }
.status-badge.locked { background: rgba(244,67,54,0.2); color: #c62828; }
.chapter-actions { margin-left: 20px; }
@media (max-width: 768px) { .container { padding: 0 15px; } .modal-content { padding: 20px; } .subjects-grid { grid-template-columns: 1fr; } }