diff --git a/AGENTS.md b/AGENTS.md
index 3a19f167..670e01a2 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -259,6 +259,11 @@ pnpm dev
 4. **Scrollable containers:** `overflow-y: auto; min-height: 0;` (enables internal scroll without page scroll)
 5. **Grid layouts:** `align-items: start;` (NOT center/stretch) to prevent column stretching at different heights
 6. **Max-width constraint:** Wrap pages in `.page-wrapper { max-width: var(--ks-content-max); margin: 0 auto; }` to prevent 2560px+ distortion
+7. **PageLayout must use CSS Grid (NOT flexbox).** Flex + gap breaks `flex: 1` height propagation in children:
+   - ❌ **DON'T:** `display: flex; flex-direction: column; gap: var(--ks-space-2);` (gap is not counted in flex: 1 calculations)
+   - ✅ **DO:** `display: grid; grid-template-rows: auto auto auto auto 1fr auto auto; gap: var(--ks-space-2);` (gap auto-calculated)
+   - **Reason:** Grid gap is accounted for in row sizing; flex gap is invisible to flex: 1 child height calculations, causing overflow → unwanted scroll
+   - **Template rows:** header (auto) | subtitle (auto) | commandBar (auto) | summary (auto) | filters (auto) | workspace (1fr) | footer (auto)
 
 #### Page Structure Rule: NO Footers (Global or Page-Level)
 **CRITICAL:** Footers are EXCLUDED at all levels:
diff --git a/frontend/src/shared/ui/layouts/PageLayout.vue b/frontend/src/shared/ui/layouts/PageLayout.vue
index 6896825e..42de8733 100644
--- a/frontend/src/shared/ui/layouts/PageLayout.vue
+++ b/frontend/src/shared/ui/layouts/PageLayout.vue
@@ -39,7 +39,8 @@ const showHelp = ref(false)
   </section>
 </template>
 <style scoped>
-.ks-page { width: 100%; max-width: var(--ks-content-max); margin: 0 auto; height: 100%; flex: 1; display: flex; flex-direction: column; gap: var(--ks-space-2); }
+/* Grid-based page layout: gap is automatically calculated and doesn't break flex: 1 height propagation */
+.ks-page { width: 100%; max-width: var(--ks-content-max); margin: 0 auto; height: 100%; flex: 1; display: grid; grid-template-rows: auto auto auto auto 1fr auto auto; gap: var(--ks-space-2); }
 .ks-page__header { display: flex; align-items: center; justify-content: space-between; gap: var(--ks-space-4); flex-shrink: 0; min-height: 32px; border-bottom: 1px solid var(--ks-color-neutral-200); padding-bottom: var(--ks-space-2); }
 .ks-page__title-group { display: flex; flex-direction: column; gap: 2px; }
 .ks-page__breadcrumb { font-size: 11px; color: var(--ks-color-text-muted); line-height: 14px; }
@@ -47,35 +48,35 @@ const showHelp = ref(false)
 .ks-page__header-utilities { display: flex; align-items: center; gap: var(--ks-space-2); flex-shrink: 0; }
 .ks-page__subtitle-box { margin: 0; }
 .ks-page__subtitle { margin: 0; color: var(--ks-color-text-muted); font-size: var(--ks-font-body); padding: var(--ks-space-2); background: var(--ks-color-canvas); border-radius: var(--ks-radius-sm); border: 1px solid var(--ks-color-border); }
-.ks-help-btn, .ks-ai-btn { 
-  border: 1px solid var(--ks-color-action); 
-  background: var(--ks-color-surface); 
-  border-radius: var(--ks-radius-sm); 
-  padding: 2px 8px; 
-  font-size: 11px; 
+.ks-help-btn, .ks-ai-btn {
+  border: 1px solid var(--ks-color-action);
+  background: var(--ks-color-surface);
+  border-radius: var(--ks-radius-sm);
+  padding: 2px 8px;
+  font-size: 11px;
   font-weight: 600;
-  color: var(--ks-color-action); 
-  cursor: pointer; 
+  color: var(--ks-color-action);
+  cursor: pointer;
   display: inline-flex;
   align-items: center;
   gap: 4px;
-  transition: all 0.15s ease; 
+  transition: all 0.15s ease;
 }
-.ks-help-btn:hover, .ks-help-btn.active, .ks-ai-btn:hover { 
-  background: var(--ks-color-action); 
-  color: #ffffff; 
-  border-color: var(--ks-color-action); 
+.ks-help-btn:hover, .ks-help-btn.active, .ks-ai-btn:hover {
+  background: var(--ks-color-action);
+  color: #ffffff;
+  border-color: var(--ks-color-action);
   box-shadow: 0 1px 3px rgba(37, 99, 235, 0.25);
 }
-.ks-page__command-bar { 
-  display: flex; 
-  align-items: center; 
+.ks-page__command-bar {
+  display: flex;
+  align-items: center;
   justify-content: flex-start;
-  padding: 4px 8px; 
-  background: var(--ks-color-surface); 
-  border: 1px solid var(--ks-color-border); 
-  border-radius: var(--ks-radius-sm); 
-  flex-shrink: 0; 
+  padding: 4px 8px;
+  background: var(--ks-color-surface);
+  border: 1px solid var(--ks-color-border);
+  border-radius: var(--ks-radius-sm);
+  flex-shrink: 0;
   min-height: 34px;
   box-sizing: border-border-box;
 }
@@ -106,8 +107,8 @@ const showHelp = ref(false)
   box-sizing: border-box;
   font-family: inherit;
 }
-.ks-page__workspace { min-width: 0; flex: 1; display: grid; min-height: 0; gap: var(--ks-space-4); }
+.ks-page__workspace { min-width: 0; min-height: 0; display: grid; gap: var(--ks-space-4); }
 .ks-page__workspace.has-aside { grid-template-columns: minmax(0, 1fr) var(--ks-aside-width); }
-.ks-page__content, .ks-page__aside { min-width: 0; min-height: 0; height: 100%; display: flex; flex-direction: column; }
+.ks-page__content, .ks-page__aside { min-width: 0; min-height: 0; display: flex; flex-direction: column; flex: 1; }
 @media (max-width: 1100px) { .ks-page__workspace.has-aside { grid-template-columns: 1fr; } }
 </style>