fix: sync stacked more animation with container

static/src/components/chat/StackedBlocks.vue

@@ -153,6 +153,11 @@ const moreHeight = ref(0);
 const innerOffset = ref(0);
 const viewportHeight = ref(0);
 const contentHeights = ref<Record<string, number>>({});
+const ANIMATION_SYNC_MS = 360;
+const MORE_ANIMATION_MS = 300;
+let syncRaf: number | null = null;
+let syncUntil = 0;
+const isMoreAnimating = ref(false);
 
 const stackableActions = computed(() => (props.actions || []).filter((item) => item && (item.type === 'thinking' || item.type === 'tool')));
 
@@ -181,18 +186,13 @@ const isToolProcessing = (action: any) => {
 const isToolCompleted = (action: any) => action?.tool?.status === 'completed';
 
 const toggleMore = () => {
-  showAll.value = !showAll.value;
-  nextTick(() => {
-    setShellMetrics();
-  });
+  animateMoreToggle(!showAll.value);
 };
 
 const toggleBlock = (blockId: string) => {
   if (typeof props.toggleBlock === 'function') {
     props.toggleBlock(blockId);
-    nextTick(() => {
-      setShellMetrics();
-    });
+    nextTick(() => runSync());
   }
 };
 
@@ -222,7 +222,7 @@ const moreBaseHeight = () => {
   return Math.max(48, Math.ceil(label?.getBoundingClientRect().height || 56));
 };
 
-const setShellMetrics = (expandedOverride: Record<string, boolean> = {}) => {
+const setShellMetrics = () => {
   const innerEl = resolveEl(inner.value);
   const shellEl = resolveEl(shell.value);
   if (!shellEl || !innerEl) return;
@@ -234,18 +234,13 @@ const setShellMetrics = (expandedOverride: Record<string, boolean> = {}) => {
   children.forEach((el, idx) => {
     const action = stackableActions.value[idx];
     const key = blockKey(action, idx);
-    const header = el.querySelector('.collapsible-header') as HTMLElement | null;
     const content = el.querySelector('.collapsible-content') as HTMLElement | null;
-    const progress = el.querySelector('.progress-indicator') as HTMLElement | null;
-    const expanded = typeof expandedOverride[key] === 'boolean' ? expandedOverride[key] : isExpanded(action, idx);
-    const headerH = header ? header.getBoundingClientRect().height : 0;
     const contentHeight = content ? Math.ceil(content.scrollHeight) : 0;
     nextContentHeights[key] = contentHeight;
-    const contentH = expanded ? contentHeight : 0;
-    // 进度条是绝对定位的，不应计入布局高度，否则会导致块高度在运行时膨胀几像素
-    const progressH = 0;
-    const borderH = idx < children.length - 1 ? parseFloat(getComputedStyle(el).borderBottomWidth) || 0 : 0;
-    heights.push(Math.ceil(headerH + contentH + progressH + borderH));
+
+    // 使用当前真实高度而非「展开/折叠」状态推导值，避免在折叠动画过程中出现高度骤减导致的闪烁
+    const liveHeight = Math.ceil(el.getBoundingClientRect().height || el.offsetHeight || 0);
+    heights.push(liveHeight);
   });
 
   contentHeights.value = nextContentHeights;
@@ -265,6 +260,97 @@ const setShellMetrics = (expandedOverride: Record<string, boolean> = {}) => {
   viewportHeight.value = Math.max(0, targetShell - moreHeight.value);
 };
 
+const lerp = (a: number, b: number, t: number) => a + (b - a) * t;
+const easeOutCubic = (t: number) => 1 - Math.pow(1 - t, 3);
+
+const animateMoreToggle = (nextShowAll: boolean) => {
+  if (isMoreAnimating.value) return;
+
+  // 停掉其他同步，避免冲突
+  if (syncRaf) {
+    cancelAnimationFrame(syncRaf);
+    syncRaf = null;
+  }
+
+  const innerEl = resolveEl(inner.value);
+  const shellEl = resolveEl(shell.value);
+  if (!innerEl || !shellEl) {
+    showAll.value = nextShowAll;
+    nextTick(() => runSync());
+    return;
+  }
+
+  // 先计算当前状态
+  setShellMetrics();
+  const start = {
+    shell: shellHeight.value,
+    offset: innerOffset.value,
+    viewport: viewportHeight.value,
+    more: moreHeight.value
+  };
+
+  // 切换到目标状态并计算目标值
+  showAll.value = nextShowAll;
+  setShellMetrics();
+  const target = {
+    shell: shellHeight.value,
+    offset: innerOffset.value,
+    viewport: viewportHeight.value,
+    more: moreHeight.value
+  };
+
+  // 回到起点数值，准备动画
+  shellHeight.value = start.shell;
+  innerOffset.value = start.offset;
+  viewportHeight.value = start.viewport;
+  moreHeight.value = start.more;
+
+  isMoreAnimating.value = true;
+  const startedAt = performance.now();
+
+  const step = () => {
+    const now = performance.now();
+    const t = Math.min(1, (now - startedAt) / MORE_ANIMATION_MS);
+    const eased = easeOutCubic(t);
+
+    shellHeight.value = lerp(start.shell, target.shell, eased);
+    innerOffset.value = lerp(start.offset, target.offset, eased);
+    viewportHeight.value = lerp(start.viewport, target.viewport, eased);
+    moreHeight.value = lerp(start.more, target.more, eased);
+
+    if (t < 1) {
+      requestAnimationFrame(step);
+    } else {
+      isMoreAnimating.value = false;
+      shellHeight.value = target.shell;
+      innerOffset.value = target.offset;
+      viewportHeight.value = target.viewport;
+      moreHeight.value = target.more;
+      setShellMetrics();
+    }
+  };
+
+  requestAnimationFrame(step);
+};
+
+const runSync = () => {
+  if (isMoreAnimating.value) return;
+  if (syncRaf) {
+    cancelAnimationFrame(syncRaf);
+    syncRaf = null;
+  }
+  syncUntil = performance.now() + ANIMATION_SYNC_MS;
+  const step = () => {
+    setShellMetrics();
+    if (performance.now() < syncUntil) {
+      syncRaf = requestAnimationFrame(step);
+    } else {
+      syncRaf = null;
+    }
+  };
+  syncRaf = requestAnimationFrame(step);
+};
+
 let resizeObserver: ResizeObserver | null = null;
 let heightRaf: number | null = null;
 
@@ -293,18 +379,20 @@ onBeforeUnmount(() => {
     cancelAnimationFrame(heightRaf);
     heightRaf = null;
   }
+  if (syncRaf) {
+    cancelAnimationFrame(syncRaf);
+    syncRaf = null;
+  }
 });
 
 watch([stackableActions, moreVisible], () => {
-  nextTick(() => {
-    setShellMetrics();
-  });
+  nextTick(() => runSync());
 });
 
 watch(
   () => (props.expandedBlocks ? props.expandedBlocks.size : 0),
   () => {
-    nextTick(() => setShellMetrics());
+    nextTick(() => runSync());
   }
 );
 </script>

static/src/styles/components/chat/_chat-area.scss

@@ -324,16 +324,12 @@
     background: var(--claude-card);
     box-shadow: var(--claude-shadow);
     overflow: hidden;
-    transition:
-        height 280ms cubic-bezier(0.25, 0.9, 0.3, 1),
-        padding-top 280ms cubic-bezier(0.25, 0.9, 0.3, 1);
     min-height: 0;
 }
 
 .stacked-inner {
     position: relative;
     width: 100%;
-    transition: transform 280ms cubic-bezier(0.25, 0.9, 0.3, 1);
 }
 
 .stacked-viewport {