Feat: Modify the background color of the canvas #9869 (#10507)

### What problem does this PR solve?

Feat: Modify the background color of the canvas #9869

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/data-flow/canvas/index.tsx

@@ -205,7 +205,7 @@ function DataFlowCanvas({ drawerVisible, hideDrawer, showLogSheet }: IProps) {
   };
 
   return (
-    <div className={styles.canvasWrapper}>
+    <div className={cn(styles.canvasWrapper, 'px-5 pb-5')}>
       <svg
         xmlns="http://www.w3.org/2000/svg"
         style={{ position: 'absolute', top: 10, left: 0 }}