Buttons can be created by adding .btn class to a link or button element. By it's self the .btn class does not do much besides create some basic structure. To apply styles to the button we need to add an extender class like .btn-default or .btn-primary

For webmasters needing to add application behavior there are a few additional classes that might be useful. .active will make buttons appear pressed.

Add the .disabled class to make buttons appear unclickable by fading them back 50%. Add the disabled="disabled" attribute to <button> buttons instead of the class.