[Backdrop] Comment on z-index use case (#18589)

mui · Nov 28, 2019 · a5f4a4d · a5f4a4d
1 parent 2c41ac9
commit a5f4a4d
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/packages/material-ui/src/Backdrop/Backdrop.js b/packages/material-ui/src/Backdrop/Backdrop.js
@@ -7,6 +7,7 @@ import Fade from '../Fade';
 export const styles = {
   /* Styles applied to the root element. */
   root: {
+    // Improve scrollable dialog support.
     zIndex: -1,
     position: 'fixed',
     display: 'flex',