Give the editor tab bar a specific separate background

Author: chvp

src/frontend/components/EditorTabs.ts

@@ -18,7 +18,7 @@ export class EditorTabs extends PapyrosElement {
                 flex-direction: row;
                 gap: 0.25rem;
                 padding: 0.25rem 0.25rem 0;
-                background-color: var(--md-sys-color-surface-container);
+                background-color: var(--md-sys-color-surface-dim);
                 border-radius: 0.5rem 0.5rem 0 0;
                 max-height: 2.5rem;
                 flex-shrink: 0;