Check out example codes for "inline style css syntax". It will help you in understanding the concepts better.

Code Example 1

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

  <body>

Code Example 2

<!DOCTYPE html>
<html>
<body>

<h1 style="color:blue;text-align:center;">This 
  is a heading</h1>
<p style="color:red;">This is a paragraph.</p>


  </body>
</html>

Learn ReactJs, React Native from akashmittal.com