diff --git a/frontend/src/index.css b/frontend/src/index.css
index 4cc2cfc4..05a11ad4 100644
--- a/frontend/src/index.css
+++ b/frontend/src/index.css
@@ -315,3 +315,53 @@
     @apply invisible;
   }
 }
+
+/* React Flow dark theme overrides */
+.react-flow__background {
+  background-color: hsl(var(--background));
+}
+
+.react-flow__controls {
+  background-color: hsl(var(--card));
+  border-color: hsl(var(--border));
+  border-radius: 0.75rem;
+  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
+}
+
+.react-flow__controls-button {
+  background-color: hsl(var(--card));
+  border-color: hsl(var(--border));
+  fill: hsl(var(--muted-foreground));
+}
+
+.react-flow__controls-button:hover {
+  background-color: hsl(var(--accent));
+}
+
+.react-flow__minimap {
+  background-color: hsl(var(--card));
+  border-color: hsl(var(--border));
+  border-radius: 0.75rem;
+}
+
+.react-flow__edge-path {
+  stroke: hsl(var(--border));
+}
+
+.react-flow__edge-text {
+  fill: hsl(var(--muted-foreground));
+}
+
+.react-flow__edge-textbg {
+  fill: hsl(var(--card));
+}
+
+/* Hide default React Flow attribution */
+.react-flow__attribution {
+  display: none;
+}
+
+/* Handle styles */
+.react-flow__handle {
+  background-color: hsl(var(--border));
+}