Q: Why does the BGS not display the CSS animation in IE7, 8, 9 ?
A: These old browsers do not support CSS3 animations.
In IE versions older than 10, the CSS3 animations cannot be displayed, since these old browsers do not support CSS.
Instead, a 'normal' , not animated background image will be displayed due to the lack of function in these browsers.
If you are using one of these old browsers, we recommend upgrading at least to IE 10, or to use a alternative browser like Chrome or Firefox.