diff --git a/packages/components/src/components/post-header/post-header.scss b/packages/components/src/components/post-header/post-header.scss
index cbded0ac45..2b22afd3ed 100644
--- a/packages/components/src/components/post-header/post-header.scss
+++ b/packages/components/src/components/post-header/post-header.scss
@@ -110,6 +110,10 @@ slot[name='post-logo'] {
     z-index: 1;
     inset-block-start: var(--global-header-height);
     padding-inline: var(--post-core-dimension-8) var(--post-core-dimension-16);
+
+    &.title-header-mobile-extended {
+      border-bottom: 1px solid var(--post-core-color-sandgrey-012);
+    }
   }
 }
 
diff --git a/packages/components/src/components/post-header/post-header.tsx b/packages/components/src/components/post-header/post-header.tsx
index 9e04361563..fa1d21ecb1 100644
--- a/packages/components/src/components/post-header/post-header.tsx
+++ b/packages/components/src/components/post-header/post-header.tsx
@@ -150,7 +150,12 @@ export class PostHeader {
             </div>
           </div>
         </div>
-        <div class="title-header d-flex space-between align-center">
+        <div
+          class={
+            'title-header d-flex space-between align-center ' +
+            (this.mobileMenuExtended ? 'title-header-mobile-extended' : '')
+          }
+        >
           <slot name="title"></slot>
           <div class="global-sub">
             <slot name="local-controls"></slot>
diff --git a/packages/components/src/components/post-megadropdown/post-megadropdown.scss b/packages/components/src/components/post-megadropdown/post-megadropdown.scss
index 3871f4d11c..c489f8c48b 100644
--- a/packages/components/src/components/post-megadropdown/post-megadropdown.scss
+++ b/packages/components/src/components/post-megadropdown/post-megadropdown.scss
@@ -45,6 +45,7 @@ post-popovercontainer {
     left: 0;
     width: 100%;
     height: auto;
+    border-top: unset;
 
     &.slide-in {
       animation: slide-in;