diff --git a/src/components/Sidebar.tsx b/src/components/Sidebar.tsx
index 22eb335..39c58a1 100644
--- a/src/components/Sidebar.tsx
+++ b/src/components/Sidebar.tsx
@@ -35,29 +35,14 @@ const SidebarContent: Component<SidebarContentProps> = (props) => {
       props.pathHeadings[pathname] || props.pathHeadings[`${pathname}.md`] || []
     );
   });
-  const revealedHeadings = createMemo(() => {
-    const pathname = decodeURIComponent(location.pathname);
-    const set = new Set<string>();
-    function traverse(node: TocNode, cb: (node: TocNode) => void) {
-      cb(node);
-      node.children?.forEach((child) => traverse(child, cb));
-    }
-    for (const node of currentFileHeadings()) {
-      traverse(node, (anode) => {
-        if (isPathRevealed(pathname, anode.id ?? anode.title)) {
-          traverse(anode, (each) => set.add(anode.id ?? anode.title));
-        }
-      });
-    }
-    return set;
-  });
   const isFileHidden = (node: FileNode): boolean => {
     if (isPathRevealed(node.path)) return false;
     if (node.children?.some((child) => !isFileHidden(child))) return false;
     return true;
   };
   const isHeadingHidden = (node: TocNode): boolean => {
-    if (revealedHeadings().has(node.id ?? node.title)) return false;
+    const pathname = decodeURIComponent(location.pathname);
+    if (isPathRevealed(pathname, node.id ?? node.title)) return false;
     if (node.children?.some((child) => !isHeadingHidden(child))) return false;
     return true;
   };
diff --git a/src/components/stores/journalStream.ts b/src/components/stores/journalStream.ts
index 2d33b4a..c4716f0 100644
--- a/src/components/stores/journalStream.ts
+++ b/src/components/stores/journalStream.ts
@@ -676,11 +676,26 @@ export function addRevealedClasses(root: HTMLDivElement, path: string) {
   };
   for (const child of root.children) collect(child);
 
-  // ---- Cascade: if a heading is revealed, its parents are too ----
-  const revealedSet = new Set<string>();
+  // ---- Cascade: directly revealed headings propagate ----
+  // 1. directly revealed headings
+  const revealedSet = new Set<string>(revealed);
+
+  // 2. Downward: all children of directly revealed headings
+  // let changed = true;
+  // while (changed) {
+  //   changed = false;
+  //   for (const h of headings) {
+  //     if (revealedSet.has(h.text)) continue;
+  //     if (h.parents.some((p) => revealedSet.has(p))) {
+  //       revealedSet.add(h.text);
+  //       changed = true;
+  //     }
+  //   }
+  // }
+
+  // 3. Upward: all parents of directly revealed headings
   for (const h of headings) {
-    if (revealed.has(h.text) || revealedSet.has(h.text)) {
-      revealedSet.add(h.text);
+    if (revealed.has(h.text)) {
       for (const p of h.parents) revealedSet.add(p);
     }
   }