.topic-layout { display: grid; gap: 24px; padding: 24px 0; }
.filter-section { margin-bottom: 24px; }
.filter-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; max-height: 85px;overflow: hidden;}
.filter-tag {
    padding: 8px 16px; background: var(--bg-primary); border: 1px solid var(--border-color);
    border-radius: 20px; font-size: 13px; color: var(--text-secondary);
    transition: all var(--transition-fast); cursor: pointer;
}
.filter-tag:hover { border-color: var(--color-primary); color: var(--color-primary); }
.filter-tag.active { background: var(--color-primary); border-color: var(--color-primary); color: #fff; }
.expand-tags { font-size: 13px; color: var(--color-primary); cursor: pointer; display: flex; align-items: center; gap: 4px; margin-top: 8px; }
.expand-tags i { font-size: 11px; }
.expand-tags .rotate-180 {
    transform: translate(0, 0) rotate(var(--tw-rotate)) skewX(180deg) skewY(0) scaleX(1) scaleY(1);
    --tw-rotate: 180deg;
    margin-top: -3px;
    padding-top: 3px;
}
.article-count { font-size: 20px; font-weight: 700; color: var(--text-primary); margin-bottom: 20px; }
.article-count span { color: var(--text-muted); font-weight: 400; }
.topic-grid { display: grid; grid-template-columns: 1fr; gap: 20px; }
@media (min-width: 640px) { .topic-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .topic-grid { grid-template-columns: repeat(3, 1fr); } }
@media (min-width: 1280px) { .topic-grid { grid-template-columns: repeat(4, 1fr); } }
.topic-card {
    background: var(--bg-primary); border: 1px solid var(--border-color);
    border-radius: var(--radius-md); overflow: hidden;
    transition: all var(--transition-fast); cursor: pointer;
}
.topic-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); border-color: var(--color-primary); }
.topic-card-image { position: relative; height: 160px; overflow: hidden; background: linear-gradient(135deg, #1a1a2e, #16213e); }
.topic-card .topic-card-tags { position: absolute; top: 12px; left: 12px; display: flex; gap: 6px; }
.topic-card-tag {
    background: rgba(255,255,255,0.95); padding: 4px 10px;
    border-radius: 4px; font-size: 11px; font-weight: 500; color: var(--text-primary);
}
.topic-card-content { padding: 16px; }
.topic-card-title { font-size: 15px; font-weight: 600; color: var(--text-primary); line-height: 1.5; margin-bottom: 12px; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; min-height: 45px; }
.topic-card-title:hover { color: var(--color-primary); }
.topic-card-met .topic-card-author { display: flex; align-items: center; gap: 6px; }
.topic-card-author i { font-size: 10px; }
.topic-card-meta{font-size: 12px;}
.topic-card-content .time{margin-left: 5px}
.mobile-topic-nav { display: block; margin-bottom: 20px; }
@media (min-width: 1024px) { .mobile-topic-nav { display: none; } }
.mobile-topic-select {
    width: 100%; padding: 12px 16px;
    background: var(--bg-primary); border: 1px solid var(--border-color);
    border-radius: var(--radius-sm); font-size: 14px; color: var(--text-primary);
}