/* ===== 响应式样式 ===== */

/* 平板 */
@media (max-width: 992px) {
    .course-grid { grid-template-columns: repeat(3, 1fr); }
    .hero-banner { height: 300px; }
    .banner-content h2 { font-size: 28px; }
    .course-detail-header .course-cover { width: 300px; height: 200px; }
}

/* 大手机 */
@media (max-width: 768px) {
    .container { padding: 0 10px; }
    .header-inner { flex-wrap: wrap; height: auto; padding: 10px 0; }
    .logo { flex: 1; }
    .logo a { font-size: 16px; }
    /* 汉堡菜单 */
    .nav-toggle { display: block; order: 2; }
    .main-nav { display: none; order: 3; width: 100%; flex-direction: column; background: #fff; padding: 10px 0; border-top: 1px solid #eee; margin-top: 10px; }
    .main-nav.open { display: flex; }
    .main-nav a { padding: 10px 15px; border-bottom: 1px solid #f0f0f0; }
    .main-nav a:last-child { border-bottom: none; }
    .search-box { display: none; }
    .header-right { gap: 10px; order: 1; }
    
    .hero-banner { height: 200px; margin-bottom: 20px; }
    .banner-content { bottom: 20px; left: 5%; }
    .banner-content h2 { font-size: 20px; margin-bottom: 10px; }
    
    .category-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
    .category-card { padding: 15px; }
    .category-icon { font-size: 30px; margin-bottom: 10px; }
    .category-name { font-size: 14px; }
    
    .course-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
    .course-cover { height: 120px; }
    .course-info { padding: 10px; }
    .course-title { font-size: 14px; height: 38px; }
    .course-meta { font-size: 12px; }
    .price, .price-free { font-size: 16px; }
    
    .section { padding: 25px 0; }
    .section-title { font-size: 20px; margin-bottom: 20px; }
    
    .filter-bar { flex-direction: column; gap: 10px; align-items: stretch; padding: 12px 15px; }
    .sort-tabs { justify-content: center; flex-wrap: wrap; gap: 12px; }
    
    .course-detail-header { flex-direction: column; padding: 15px; }
    .course-detail-header .course-cover { width: 100%; height: 200px; }
    .course-basic h1 { font-size: 20px; }
    .course-actions { flex-wrap: wrap; }
    .content-tabs { flex-wrap: wrap; }
    .tab-item { padding: 10px 15px; font-size: 14px; }
    
    .user-layout { flex-direction: column; }
    .user-sidebar { width: 100%; }
    .user-menu { display: flex; flex-wrap: wrap; }
    .user-menu a { flex: 1; min-width: 100px; text-align: center; padding: 10px; border: 1px solid #eee; border-radius: 4px; font-size: 13px; }
    
    .cart-layout, .checkout-layout { flex-direction: column; }
    .cart-summary, .checkout-summary { width: 100%; position: static; }
    .cart-item, .checkout-item, .order-item, .my-course-item, .fav-item, .comment-user-item { flex-wrap: wrap; }
    .item-cover, .order-cover, .my-course-item .course-cover, .fav-cover, .comment-user-cover { width: 100%; }
    .item-cover img { height: 100px; }
    .order-cover img, .comment-user-cover img { height: 80px; }
    .my-course-item .course-cover img { height: 120px; }
    .fav-cover img { height: 100px; }
    .fav-action, .order-actions, .my-course-item .course-actions, .comment-user-item .comment-action { width: 100%; flex-direction: row; justify-content: flex-end; }
    
    .pay-layout { padding: 0 10px; }
    .method-list { flex-direction: column; }
    
    .footer-inner { grid-template-columns: repeat(2, 1fr); gap: 20px; }
    .footer-section h4 { font-size: 15px; }
}

/* 小手机 */
@media (max-width: 480px) {
    .course-grid { grid-template-columns: 1fr; }
    .footer-inner { grid-template-columns: 1fr; }
    .auth-card { padding: 25px; margin: 0 10px; }
    .auth-card h2 { font-size: 20px; }
    .video-sidebar { display: none; }
}

/* 横屏 */
@media (max-height: 500px) and (orientation: landscape) {
    .hero-banner { height: 150px; }
}

/* 打印 */
@media print {
    .site-header, .site-footer, .btn, .pagination, #toast-container, .confirm-overlay { display: none !important; }
    .main-content { padding: 0; }
    body { background: #fff; }
}