diff --git a/frontend/src/components/ol-search-bar.js b/frontend/src/components/ol-search-bar.js
index f478e8b..22618d0 100644
--- a/frontend/src/components/ol-search-bar.js
+++ b/frontend/src/components/ol-search-bar.js
@@ -124,6 +124,7 @@ export class OlSearchBar extends LitElement {
     super.disconnectedCallback();
     document.removeEventListener('click', this._onDoc, true);
     window.removeEventListener('resize', this._onWinResize);
+    if (this._mobileExpanded) document.body.style.overflow = '';
     this._acAbort?.abort();
     this._authorAbort?.abort();
     this._subjectAbort?.abort();
@@ -147,6 +148,10 @@ export class OlSearchBar extends LitElement {
     }
     // Sync full-screen overlay class on the host element.
     this.classList.toggle('mobile-exp', this._mobileExpanded);
+    // Prevent body scroll while overlay is active so the page behind doesn't scroll.
+    if (changed.has('_mobileExpanded')) {
+      document.body.style.overflow = this._mobileExpanded ? 'hidden' : '';
+    }
     // Anchor the panel to the trigger and focus the panel-input when it opens.
     if (changed.has('_open') && this._open && this.showFacets) {
       if (!this._mobileExpanded) this._positionPanel();
@@ -665,18 +670,18 @@ export class OlSearchBar extends LitElement {
       background: white; overflow: hidden;
     }
     :host(.mobile-exp) .search-outer {
-      flex: 1; display: flex; flex-direction: column;
+      flex: 1; min-height: 0; display: flex; flex-direction: column;
     }
     :host(.mobile-exp) .input-row { display: none; }
     :host(.mobile-exp) .panel {
-      position: static; flex: 1;
+      position: static; flex: 1; min-height: 0;
       width: 100%; box-sizing: border-box;
-      overflow: visible; max-height: none;
+      display: flex; flex-direction: column; overflow: hidden; max-height: none;
       border: none; box-shadow: none; border-radius: 0;
       border-top: none;
     }
     :host(.mobile-exp) .panel-chips { max-height: none; }
-    :host(.mobile-exp) .ac-scroll { max-height: 40vh; }
+    :host(.mobile-exp) .ac-scroll { flex: 1; min-height: 0; max-height: none; overflow-y: auto; }
     :host(.mobile-exp) .pf-bar { overflow: visible; flex-wrap: wrap; }
 
     /* Back button shown at top of the expanded panel */
@@ -697,7 +702,7 @@ export class OlSearchBar extends LitElement {
       .pf-bar::-webkit-scrollbar { display: none; }
       .pf-btn { font-size: 10px; padding: 11px 4px; }
       .submit { padding: 6px 10px; }
-      .ac-scroll { max-height: 40vh; }
+      :host(:not(.mobile-exp)) .ac-scroll { max-height: 40vh; }
       .panel-chips { max-height: 72px; overflow-y: auto; }
     }
   `;
diff --git a/frontend/src/components/ol-search-bar.mobile-overlay.test.js b/frontend/src/components/ol-search-bar.mobile-overlay.test.js
index 517d918..b6ad2f8 100644
--- a/frontend/src/components/ol-search-bar.mobile-overlay.test.js
+++ b/frontend/src/components/ol-search-bar.mobile-overlay.test.js
@@ -37,16 +37,39 @@ describe('ol-search-bar mobile overlay CSS contract', () => {
     expect(src).toMatch(/:host\(\.mobile-exp\)\s+\.panel[^}]*max-height\s*:\s*none/);
   });
 
-  it(':host(.mobile-exp) .ac-scroll has a vh-based max-height for results scrolling', () => {
-    expect(src).toMatch(/:host\(\.mobile-exp\)\s+\.ac-scroll[^}]*max-height\s*:\s*\d+vh/);
+  it(':host(.mobile-exp) .ac-scroll grows to fill remaining panel height via flex: 1', () => {
+    expect(src).toMatch(/:host\(\.mobile-exp\)\s+\.ac-scroll[^}]*flex\s*:\s*1/);
+  });
+
+  it(':host(.mobile-exp) .ac-scroll has min-height:0 so it can shrink below content size', () => {
+    expect(src).toMatch(/:host\(\.mobile-exp\)\s+\.ac-scroll[^}]*min-height\s*:\s*0/);
+  });
+
+  it(':host(.mobile-exp) .panel is a flex column so children stack and ac-scroll can flex-grow', () => {
+    expect(src).toMatch(/:host\(\.mobile-exp\)\s+\.panel[^}]*display\s*:\s*flex/);
+    expect(src).toMatch(/:host\(\.mobile-exp\)\s+\.panel[^}]*flex-direction\s*:\s*column/);
+  });
+
+  it('@media 600px .ac-scroll rule is scoped to :host(:not(.mobile-exp)) — no specificity conflict', () => {
+    const mediaBlock = src.slice(src.indexOf('@media (max-width: 600px)'), src.indexOf('@media (max-width: 600px)') + 400);
+    expect(mediaBlock).toMatch(/:host\(:not\(\.mobile-exp\)\)\s+\.ac-scroll/);
+    expect(mediaBlock).not.toMatch(/[^)]\s+\.ac-scroll\s*\{[^}]*max-height/); // plain .ac-scroll should not appear
   });
 
   it(':host(.mobile-exp) .panel sets width:100% to override the desktop CSS var', () => {
     expect(src).toMatch(/:host\(\.mobile-exp\)\s+\.panel[^}]*width\s*:\s*100%/);
   });
 
-  it(':host(.mobile-exp) .panel uses overflow:visible so facet dropdowns are not clipped', () => {
-    expect(src).toMatch(/:host\(\.mobile-exp\)\s+\.panel[^}]*overflow\s*:\s*visible/);
+  it(':host(.mobile-exp) .panel uses overflow:hidden to bound the flex scroll region', () => {
+    // In full-screen mode the panel IS the viewport, so facet dropdowns remain
+    // within its bounds and are not clipped; overflow:hidden is needed so that
+    // flex children (ac-scroll) are properly height-constrained.
+    expect(src).toMatch(/:host\(\.mobile-exp\)\s+\.panel[^}]*overflow\s*:\s*hidden/);
+  });
+
+  it(':host(.mobile-exp) .panel and .search-outer have min-height:0 so flex chain can shrink', () => {
+    expect(src).toMatch(/:host\(\.mobile-exp\)\s+\.panel[^}]*min-height\s*:\s*0/);
+    expect(src).toMatch(/:host\(\.mobile-exp\)\s+\.search-outer[^}]*min-height\s*:\s*0/);
   });
 });
 
@@ -82,4 +105,15 @@ describe('ol-search-bar mobile overlay JS contract', () => {
   it('toggles mobile-exp class on :host via updated()', () => {
     expect(src).toMatch(/classList\.toggle\s*\(\s*['"]mobile-exp['"]\s*,\s*this\._mobileExpanded\s*\)/);
   });
+
+  it('locks body scroll when mobile overlay opens and restores it when it closes', () => {
+    const updatedFn = src.slice(src.indexOf('updated(changed)'), src.indexOf('updated(changed)') + 1200);
+    expect(updatedFn).toMatch(/document\.body\.style\.overflow/);
+    expect(updatedFn).toMatch(/_mobileExpanded.*hidden|hidden.*_mobileExpanded/s);
+  });
+
+  it('restores body scroll in disconnectedCallback in case component is removed while expanded', () => {
+    const dcFn = src.slice(src.indexOf('disconnectedCallback()'), src.indexOf('disconnectedCallback()') + 400);
+    expect(dcFn).toMatch(/document\.body\.style\.overflow/);
+  });
 });
diff --git a/frontend/src/components/ol-search-bar.panel-overlay.test.js b/frontend/src/components/ol-search-bar.panel-overlay.test.js
index f1b8e02..ce51141 100644
--- a/frontend/src/components/ol-search-bar.panel-overlay.test.js
+++ b/frontend/src/components/ol-search-bar.panel-overlay.test.js
@@ -99,7 +99,7 @@ describe('ol-search-bar panel overlay — panel-input contract', () => {
   });
 
   it('updated() focuses the panel-input when the panel opens', () => {
-    const updFn = src.slice(src.indexOf('updated(changed)'), src.indexOf('updated(changed)') + 1000);
+    const updFn = src.slice(src.indexOf('updated(changed)'), src.indexOf('updated(changed)') + 1200);
     expect(updFn).toMatch(/panel-input/);
   });
 });