Some CSS rules are not scoped and mess with other modules styles

This stylesheet uses a lot of non-scoped CSS rules like this one:

* {
-webkit-box-sizing: border-box;
-moz-box-sizing: border-box;
box-sizing: border-box;
}

*:before,
*:after {
-webkit-box-sizing: border-box;
-moz-box-sizing: border-box;
box-sizing: border-box;
}

This for example makes ALL the DOM elements use the "box-sizing: border-box;" rule even if they are *not* part of a modal.

It obviously breaks a lot of styles from other modules and the core - the CKEditor config page to begin with.