/* @import url('http://example.com/example_style.css'); */

/***********************************************/
/* CSS @imports must be at the top of the file */
/* Add them above this section                 */
/***********************************************/

/*****************************************/
/* Start your style declarations here    */
/*****************************************/

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet">