fix(outline): hover 高亮残留——内联 onMouseEnter/onMouseLeave 用 if(i!==activeIdx) 条件, 点击后 activeIdx 变化导致 onMouseLeave 条件为 false 不清除背景. 改用纯 CSS :hover 替代内联 JS, 浏览器自动管理 hover 状态无竞态

apps/desktop/src/renderer/features/outline/OutlinePanel.tsx

@@ -109,10 +109,8 @@ export function OutlinePanel() {
       {headings.map((h, i) => (
         <div key={h.id} data-idx={i} onClick={() => scrollTo(h)}
           className={i === activeIdx ? 'outline-item outline-item-active' : 'outline-item'}
-          style={{ paddingLeft: 8 + (h.level - 1) * 12, cursor: 'pointer', padding: '4px 4px 4px ' + (8 + (h.level-1)*12) + 'px',
-            fontSize: 13, borderRadius: 4 }}
-          onMouseEnter={e => { if (i !== activeIdx) e.currentTarget.style.background = 'var(--control-border)'; }}
-          onMouseLeave={e => { if (i !== activeIdx) e.currentTarget.style.background = 'transparent'; }}>
+          style={{ cursor: 'pointer', padding: '4px 4px 4px ' + (8 + (h.level-1)*12) + 'px',
+            fontSize: 13, borderRadius: 4 }}>
           {h.text || '(空标题)'}
         </div>
       ))}

apps/desktop/src/renderer/styles.css

@@ -74,7 +74,8 @@ html, body, #root { margin: 0; height: 100%; }
   border-radius: 4px;
 }
 
-/* FR-O3：大纲当前项高亮——主题变量适配 */
+/* FR-O3：大纲项 hover + 当前项高亮——用 CSS :hover 避免内联 style 竞态 */
+.outline-item:hover { background: var(--control-border); }
 .outline-item-active {
   background: var(--control-border) !important;
   border-left: 2px solid var(--accent) !important;