diff --git a/frontend/src/components/Flow/flow.css b/frontend/src/components/Flow/flow.css
index f313a6b..04e1a1a 100644
--- a/frontend/src/components/Flow/flow.css
+++ b/frontend/src/components/Flow/flow.css
@@ -2,8 +2,10 @@
  * React Flow, routed through the design tokens.
  *
  * Scoped to `.react-flow` rather than added to index.css, so the canvas needs no
- * tokens of its own and follows the theme in both modes without a `colorMode`
- * prop. See the root DESIGN-GUIDELINES.md → Shells.
+ * tokens of its own. The `colorMode` prop is passed all the same: React Flow
+ * stamps it on the wrapper as a class, and `.light` / `.dark` are the app's own
+ * token scopes — an unset one defaults to `light` and re-themes the whole canvas
+ * inside a dark shell. See the root DESIGN-GUIDELINES.md → Shells.
  */
 
 .react-flow {