diff --git a/src/server/handlers/request/ssr/ssr-handler.ts b/src/server/handlers/request/ssr/ssr-handler.ts
index 21bad8c5b5..78d924ca46 100644
--- a/src/server/handlers/request/ssr/ssr-handler.ts
+++ b/src/server/handlers/request/ssr/ssr-handler.ts
@@ -576,13 +576,19 @@ function generateStyledErrorHtml(
       --title: #374151;
       --message: #9ca3af;
     }
+    /* Dark mode: system preference, .dark class, or data-theme="dark" */
     @media (prefers-color-scheme: dark) {
-      :root {
+      :root:not(.light):not([data-theme="light"]) {
         --bg: #0d0e11;
         --title: #949A9F;
         --message: #6b7280;
       }
     }
+    :root.dark, :root[data-theme="dark"] {
+      --bg: #0d0e11;
+      --title: #949A9F;
+      --message: #6b7280;
+    }
     body {
       margin: 0;
       font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;