Bootstrap includes several predefined button styles, each serving its own semantic purpose, with a few extras thrown in for more control.
Two Tone Buttons
.btn-tone to make two tone style
.btn classes are designed to be used with the
<button> element. However, you can also use these classes on
<input> elements (though some browsers may apply a slightly different rendering).
When using button classes on
<a> elements that are used to trigger in-page functionality (like collapsing content), rather than linking to new pages or sections within the current page, these links should be given a
role="button" to appropriately convey their purpose to assistive technologies such as screen readers.
.btn-xs to resize the button
.btn-block to make button full width
Wrap a series of buttons with
btn-icon to create a icon button.
btn-tone to create a 2 tone style.
.btn-rounded to make round style
.btn-rounded to make round two tone style
.is-loading class to add loading inidcator to button