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

Code Example 1

<!DOCTYPE html>
<html>
<head>
<style>

 body {background-color: powderblue;}
h1   {color: blue;}
p    {color: red;}

</style>
</head>
<body>

<h1>This is a 
 heading</h1>
<p>This is a paragraph.</p>

</body>
</html>

Code Example 2

<p style="text-align: center; color: pink;">Hello World</p>

Code Example 3

<p style="color: blue; font-size: 46px;">

Code Example 4

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

Code Example 5

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

Code Example 6

<!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