diff --git a/shared/tab-cache.ts b/shared/tab-cache.ts
index 949f83f..e146a66 100644
--- a/shared/tab-cache.ts
+++ b/shared/tab-cache.ts
@@ -255,7 +255,11 @@ export class TabCache {
 			pane.dataset.moduleId = moduleId;
 			pane.dataset.spaceSlug = space;
 			pane.dataset.pageTitle = content.title;
-			pane.innerHTML = content.body;
+			// Wrap body in .rapp-content so the flex layout + scrolling works
+			const contentWrap = document.createElement("div");
+			contentWrap.className = "rapp-content";
+			contentWrap.innerHTML = content.body;
+			pane.appendChild(contentWrap);
 			app.appendChild(pane);
 			this.panes.set(key, pane);
 
diff --git a/website/public/shell.css b/website/public/shell.css
index 7e86db4..7676814 100644
--- a/website/public/shell.css
+++ b/website/public/shell.css
@@ -551,8 +551,13 @@ body.rstack-sidebar-open #toolbar {
   display: none;
 }
 
+/* Active panes must be flex columns so subnav/tabbar/rapp-content
+   flex properties work after TabCache.init() wraps them into a pane */
 .rspace-tab-pane--active {
-  display: block;
+  display: flex;
+  flex-direction: column;
+  flex: 1;
+  min-height: 0;
 }
 
 .rspace-tab-loading {