Editor background image does not resize (includes fix)

Using Expound 2.0.1

The file /wp-content/themes/expound/css/editor-style.css
contains a problem in line 4

The editor background is defined in the following way:

body {
	background: #f3f3f3 url('../images/editor-style-bg.png') 0 0 repeat-y;
	margin: 40px;
	max-width: 700px;
	padding: 0;
}

And the referred bg-image is 780*1 pixel white.

But, since the editor window with the new version of tiny-mce now resizes, the content will sometimes flow further to the right, than those 780 pixels, which makes it look weird.

Fix in editor-style.css:

body {
	background-color: #ffffff;
	background-image: none;
}

However, being eager to fix this now, I created a file css/editor-style.css in my child theme with the following content:

@import url('/wp-content/themes/expound/css/editor-style.css?v=20131116');
body {
	background-color: #ffffff;
	background-image: none;
}