White box behind Featured Pages

I use the following CSS code from @rdellconsulting to correct a problem with the favourites background changing on large to small screens. This should work on large scale PC-monitors as well as on mobile- phones. (especially visible when Backgnd colour is changed)

@media all and (max-width: 768px) {
.widget-front .round-div {
border: 94px solid #EEEDEE;
}
}

But as soon as there is more space, in order to display all 3 favourites in narrow space, then the favourites backgnd become a rectangle again. Check on Your ipad or galaxy tab or other tablet. When it’s landscape the favourites display OK, but when it’s portrait format the problem is there again. If You reduce or enlarge the screen in a browser slowly, You will see what I mean: for a certain scale the favourites stay round, if smaller they become rectangles, and if even smaller they are round again. I didn’t find a value (until now) where it worked over all screen sizes.