.topics-container{max-width:1200px;margin:0 auto;padding:2rem}.topic-header{text-align:center;margin-bottom:2rem}.topic-header h1{font-size:2rem;margin-bottom:.5rem;color:var(--text-primary)}.topic-subtitle{color:var(--text-secondary);font-size:1rem}.topic-filter{display:flex;align-items:center;justify-content:center;gap:1rem;margin-bottom:2rem}.topic-filter label{font-weight:500;color:var(--text-primary)}.topic-filter select{padding:.5rem 1rem;border:1px solid var(--border);border-radius:8px;background:var(--surface);color:var(--text-primary);font-size:1rem;cursor:pointer}.topic-cards-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:1.5rem}.topic-card{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:2rem 1.5rem;text-align:center;cursor:pointer;transition:all .2s}.topic-card:hover{transform:translateY(-4px);box-shadow:0 4px 12px #0000001a;border-color:var(--primary)}.topic-emoji{font-size:3rem;margin-bottom:1rem}.topic-name{font-size:1.1rem;font-weight:600;color:var(--text-primary);margin-bottom:.5rem}.topic-count{font-size:.9rem;color:var(--text-secondary)}.topic-detail-screen{animation:fadeIn .3s}.topic-detail-header{margin-bottom:2rem}.topic-back-btn{display:inline-flex;align-items:center;gap:.5rem;padding:.5rem 1rem;background:var(--surface);border:1px solid var(--border);border-radius:8px;color:var(--text-primary);cursor:pointer;margin-bottom:1rem;transition:all .2s}.topic-back-btn:hover{background:var(--hover)}.topic-detail-header h2{font-size:2rem;margin-bottom:.5rem;color:var(--text-primary)}.topic-detail-count{color:var(--text-secondary);font-size:1rem}.topic-actions{display:flex;gap:1rem;margin-bottom:2rem;justify-content:center}.topic-actions button{display:inline-flex;align-items:center;gap:.5rem;padding:.75rem 1.5rem;border-radius:8px;font-size:1rem;font-weight:500;cursor:pointer;transition:all .2s}.topic-actions .btn-primary{background:var(--primary);color:#fff;border:none}.topic-actions .btn-primary:hover:not(:disabled){background:var(--primary-light)}.topic-actions .btn-secondary{background:var(--surface);color:var(--text-primary);border:1px solid var(--border)}.topic-actions .btn-secondary:hover:not(:disabled){background:var(--hover)}.topic-actions button:disabled{opacity:.5;cursor:not-allowed}.topic-vocab-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:1rem}.topic-vocab-card{background:var(--surface);border:1px solid var(--border);border-radius:8px;padding:1rem;text-align:center;transition:all .2s}.topic-vocab-card:hover{border-color:var(--primary);box-shadow:0 2px 8px #00000014}.word-hanzi{font-size:1.8rem;font-weight:600;color:var(--text-primary);margin-bottom:.5rem}.word-pinyin{font-size:.9rem;color:var(--text-secondary);margin-bottom:.5rem}.word-meaning{font-size:.9rem;color:var(--text-primary)}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}@media(max-width:768px){.topics-container{padding:1rem}.topic-cards-grid{grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:1rem}.topic-vocab-grid{grid-template-columns:repeat(auto-fill,minmax(140px,1fr))}.topic-actions{flex-direction:column}.topic-actions button{width:100%}}