diff --git a/index.html b/index.html
index 3dcd95a..4851280 100644
--- a/index.html
+++ b/index.html
@@ -272,6 +272,9 @@ let origTranslations = [];
 let origTranslateOpen = [];
 let analysisVersion = 1;
 let helpState = {};
+// 「查看之前的写作建议」(<details>) 展开状态：翻译/切换等会重建左栏 DOM，
+// 不记住的话翻译完成后会意外收起（用户实测）。
+let priorGuidanceOpen = false;
 let dirtyDuringRecheck = false;
 let transitioning = false;
 // 对话历史（快照）持久化：刷新后回对话页不丢理解/诊断/复检卡片（用户实测发现 + PM 同意修复）。
@@ -936,6 +939,9 @@ function bindAnnotationInteractions(wrap){
   wrap.querySelectorAll('.annotation-card').forEach(el=>el.onclick=e=>{ if(!e.target.closest('.why-toggle')) activate(el.dataset.noteId); });
   // 原文中文对照（逐句）：对照行与批注同色同序号 —— 点击对照行可联动高亮原文句
   wrap.querySelectorAll('[data-role="orig-translate"]').forEach(btn=>{ btn.onclick = toggleOrigTranslate; });
+  // 记住「查看之前的写作建议」的展开状态（左栏重建后恢复，避免翻译完成被收起）
+  const prior = wrap.querySelector('.prior-guidance');
+  if(prior) prior.addEventListener('toggle', ()=>{ priorGuidanceOpen = prior.open; });
   wrap.querySelectorAll('.ot-line[data-note-id]').forEach(el=>{ el.onclick = () => activate(el.dataset.noteId); });
   wrap.querySelectorAll('.why-toggle').forEach(btn=>btn.onclick=e=>{
     e.stopPropagation();
@@ -990,7 +996,7 @@ function renderFocusOriginal(wrap){
       <div class="direction-line meaning"><span class="direction-chip meaning">这段在讲什么</span><div class="direction-text">${escapeHtml(meaningOf(current))}</div></div>
     </div>`;
   const body = isRevisionTarget(current)
-    ? `${visibleMeaning}<details class="prior-guidance"><summary>查看之前的写作建议</summary>${fullDirection}${paper}</details>`
+    ? `${visibleMeaning}<details class="prior-guidance"${priorGuidanceOpen ? ' open' : ''}><summary>查看之前的写作建议</summary>${fullDirection}${paper}</details>`
     : fullDirection + paper;
   wrap.className = 'original-workspace';
   wrap.innerHTML = `${banner}${body}<div class="context-hint"><div class="context-label">和上下文怎么接</div><div class="context-copy">${escapeHtml(contextHintOf(current))}</div></div>`;
@@ -1038,9 +1044,14 @@ function updateParagraphSwitcherState(){
 }
 function renderOriginalPane(){
   const wrap=$('#originalFull');
+  // 重建 DOM 前记住滚动位置：「查看之前的写作建议」展开后点翻译/切视图等
+  // 都会走到这里，不恢复会导致内容跳回顶部
+  const body = wrap.closest('.pane-body');
+  const scrollTop = body ? body.scrollTop : 0;
   wrap.innerHTML='';
   if(originalView==='focus') renderFocusOriginal(wrap); else renderFullOriginal(wrap);
   renderParagraphSwitcher();
+  if(body) body.scrollTop = scrollTop;
 }
 function updateProgress(){
   const n = rewrittenCount();