How to style default confirm box with only css?
Solution 1:
It is not possible. This window is displayed by the browser using the platform's UI kit. It's not in the DOM, not visible from the CSS or Javascript, there's nothing you can do.
However, some very simple jQuery code can do the trick. How about $('a').confirm(); ?
Solution 2:
confirm(); alerts cannot be styled, they are generic to the browser. If you want to style an alert, try alternatives such as boxy, or the jQuery dialog box.
Here is a tutorial about how a custom confirm alert can be created in jQuery and styled with CSS.