style: add font styling and padding to image generation placeholder

Author: jchris

src/components/ImgGenUtils/ImgGenPromptWaiting.tsx

@@ -11,7 +11,14 @@ export function ImgGenPromptWaiting({
   classes?: ImgGenClasses;
 }) {
   return (
-    <div className={combineClasses('imggen-placeholder', className, classes.placeholder)}>
+    <div
+      style={{
+        color: '#eee',
+        fontSize: 'var(--imggen-font-size)',
+        padding: '20px',
+      }}
+      className={combineClasses('imggen-placeholder', className, classes.placeholder)}
+    >
       Waiting for prompt
     </div>
   );