The admin bar should force its own style

[Pier-Olivier Thibault]

Problem is when the user uses very loose CSS selector to style his theme, it can clash with the dialogs and the

element.

The solution is to use a high specificity selector to force font-size, color, margin and what not so it can't be easily overridden.

It will still be possible to override it but if it happens, at least it will happen because the CSS is explicitly overriding it.

On a side note, this wouldn't happen if the scope attribute would be implemented.