diff --git a/site/src/components/MmpChart.svelte b/site/src/components/MmpChart.svelte
index 7432f1a..cbdb4bf 100644
--- a/site/src/components/MmpChart.svelte
+++ b/site/src/components/MmpChart.svelte
@@ -187,6 +187,11 @@
   ];
 </script>
 
+<style>
+  /* Plot tooltips always have a white background — force black text for contrast */
+  :global(.plot-tip text) { fill: #18181b !important; }
+</style>
+
 <!-- Range selector pills -->
 <div class="flex flex-wrap gap-2 mb-4">
   {#each allRangeKeys as key, i}