import css

CSS
  <!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" type="text/css" 
  href="mystyle.css">
</head>
<body>

<h1>This is a heading</h1>

  <p>This is a paragraph.</p>

</body>
</html> <link rel="stylesheet" type="text/css" href="style.css"> <link rel="stylesheet" type="text/css" href="mystyle.css">@import url("base.css");
Source

Also in CSS: