sample css file code example

Example 1: add stylesheet html

<link rel="stylesheet" type="text/css" href="style.css">

Example 2: external style sheet

<link rel="stylesheet" type="text/css" href="mystyle.css">

Example 3: css without separate file

just add any style inside the first <p> or other element tag using style=" ;" 
<p style="font-size: xx-large;">test</p>