*{margin:0;padding:0;box-sizing:border-box}:root{--bg-color: #ffffff;--text-color: #000000;--border-color: #d9d9d9;--card-bg: #ffffff;--secondary-bg: #f5f5f5;--hover-bg: #e6f7ff}[data-theme=dark]{--bg-color: #1f1f1f;--text-color: #ffffff;--border-color: #434343;--card-bg: #2d2d2d;--secondary-bg: #3d3d3d;--hover-bg: #4a4a4a}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background-color:var(--bg-color);color:var(--text-color);transition:background-color .3s,color .3s}code{font-family:source-code-pro,Menlo,Monaco,Consolas,Courier New,monospace}.topic-card{margin-bottom:16px;cursor:pointer;transition:all .3s;background-color:var(--card-bg)}.topic-card:hover{box-shadow:0 2px 8px #00000026}.pinned-badge{background:#ff4d4f;color:#fff;padding:2px 8px;border-radius:4px;font-size:12px;margin-right:8px}.tag-badge{margin-left:8px}.topic-title{font-weight:700;font-size:16px;margin-bottom:8px}.topic-preview{color:var(--text-color);opacity:.7;font-size:14px;margin-bottom:8px}.topic-meta{color:var(--text-color);opacity:.6;font-size:12px}.like-btn.active{color:#1890ff}.dislike-btn.active{color:#ff4d4f}