diff --git a/frontend/src/lib/document/TimelineDensityFilter.svelte b/frontend/src/lib/document/TimelineDensityFilter.svelte
index e82e521e..5d5e4554 100644
--- a/frontend/src/lib/document/TimelineDensityFilter.svelte
+++ b/frontend/src/lib/document/TimelineDensityFilter.svelte
@@ -358,7 +358,9 @@ const omitTickYear = $derived.by(() => {
 }
 
 :global(.dark) {
-	--timeline-bar-idle: #0d3358;
+	/* 3.33:1 against --c-surface (#011526) — clears WCAG 1.4.11 non-text contrast
+	   for large UI elements; previous #0d3358 measured 1.44:1. */
+	--timeline-bar-idle: #3a6e8c;
 	--timeline-bar-outside: #1a2735;
 }