.material-card-image { position: relative; padding-top: 75%; overflow: hidden; background: #bdbdbd; }
.material-card-image img { position: absolute; top: 0; left: 0; width: 100%; height: 100%; object-fit: contain; }
.material-card-info { padding: 15px; }
.material-card-title { font-size: 14px; color: #333; margin-bottom: 8px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.material-card-meta { font-size: 12px; color: #999; }
.material-card-tags { margin-top: 8px; }
.material-card-tags .tag { display: inline-block; padding: 2px 8px; background: #f0f0f0; color: #666; border-radius: 3px; font-size: 12px; margin-right: 5px; margin-bottom: 5px; }
.materials-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 20px; margin-top: 20px; }
.material-card { background: #fff; border-radius: 8px; overflow: hidden; transition: all 0.3s; box-shadow: 0 2px 8px rgba(0,0,0,0.08); }
.material-card:hover { transform: translateY(-5px); box-shadow: 0 8px 20px rgba(0,0,0,0.12); }
.material-card-overlay { position: absolute; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.5); display: flex; align-items: center; justify-content: center; gap: 10px; opacity: 0; transition: opacity 0.3s; }
.material-card:hover .material-card-overlay { opacity: 1; }
.material-card-overlay .btn { padding: 8px 16px; font-size: 13px; }
.category-tabs { display: flex; flex-wrap: wrap; gap: 10px; padding: 15px 0; }
.category-tab { padding: 8px 20px; background: #f5f5f5; color: #333; border-radius: 20px; text-decoration: none; font-size: 14px; transition: all 0.3s; }
.category-tab:hover, .category-tab.active { background: #0066FF; color: white; }
.category-sub-tabs { display: none; flex-wrap: wrap; gap: 8px; padding: 10px 0; }
.category-sub-tabs.show { display: flex !important; }
.breadcrumb { display: flex; align-items: center; gap: 8px; padding: 15px 0; font-size: 14px; color: #999; flex-wrap: wrap; }
.breadcrumb a { color: #666; text-decoration: none; }
.breadcrumb a:hover { color: #0066FF; }
@media (max-width: 768px) {
    .materials-grid { grid-template-columns: repeat(2, 1fr) !important; gap: 10px !important; }
    .material-card-info { padding: 10px !important; }
    .material-card-title { font-size: 12px !important; }
    .material-card-tags { display: none !important; }
    .material-card-overlay { opacity: 1 !important; background: rgba(0,0,0,0.3) !important; }
}