A similar problem to the one discussed in my previous article crops up if you want to style the Search button of the WordPress search widget. If you’re using a front-end framework like Foundation or Bootstrap, you’ll want to add one of the predefined classes to this button, instead of styling it directly.
Add a Class to the WordPress Comment Submit Button
Have you ever tried to add a custom class to the Submit button at the end of the standard WordPress comment form? It should be a very easy thing to do, but up until recently, you had to use one of several hacks to achieve this. WordPress core always did allow you to change almost all of the comment form’s elements, except for the button’s class.