diff --git a/src/components/Header/Header.astro b/src/components/Header/Header.astro
index 8c206f9078..f6f086196f 100644
--- a/src/components/Header/Header.astro
+++ b/src/components/Header/Header.astro
@@ -124,8 +124,8 @@ const primaryLink = isEnterpriseSection
 		height: var(--theme-navbar-height);
 		z-index: 11;
 		padding: 0.75rem 0;
-		background-color: color-mix(in srgb, var(--theme-navbar-bg) 95%, transparent);
-		backdrop-filter: blur(5px);
+		background-color: var(--theme-navbar-bg);
+		border-bottom: 1px solid var(--theme-divider);
 		display: flex;
 		align-items: center;
 		justify-content: left;
diff --git a/src/styles/theme.css b/src/styles/theme.css
index 9c1c497df8..9ab9680e86 100644
--- a/src/styles/theme.css
+++ b/src/styles/theme.css
@@ -186,8 +186,10 @@
   --theme-code-del-border: hsl(338, 46%, 53%);
   --theme-code-del-text: hsl(338, 36%, 70%);
 
-  /* Navbar */
-  --theme-navbar-bg: var(--theme-bg);
+  /* Navbar — content surface (white in light) so it reads as a distinct
+     elevated zone over the body bg. Dark mode aliases --theme-bg-content
+     to --theme-bg, so this is unchanged from the previous behaviour there. */
+  --theme-navbar-bg: var(--theme-bg-content);
 
   /* Glow */
   --theme-glow-highlight: transparent;