How to use WordPress 3.8 back-end CSS in front-end?
I want to use the back-end button CSS, button icons CSS etc. onto the front-end side. Is there any way, I can just call the CSS class in front-end to use them directly?
I believe you're asking how to include the admin styles in your front end theme? If so, you simply need to either enqueue 'wp-admin' on it's own or list it as a dependency for your theme/plugin stylesheet. Here are examples of both methods:
wp_enqueue_style( 'wp-admin' );
As a dependency:
wp_enqueue_style( 'my-theme-styles', 'path-to-my-css.css', array( 'wp-admin' ), '1.0.0' );
There are also several individual parts of the admin css that can be enqueued separately as well:
'dashicons' 'admin-bar' 'thickbox' 'wp-admin' 'buttons' 'colors'
Although enqueueing any of these individually may have less than ideal results as I don't believe they are listed as dependent on eachother.