How to Use CSS in HTML ?

There is more than one way to add a Cascading Style Sheet (CSS) to your HTML document. In this short tutorial I will explain the strengths and weaknesses of the four main methods.
Here is Four methods of adding CSS to HTML.

  • Internal Style Sheet
  • External Style Sheet
  • Inline style

External Style Sheet

With an external style sheet, you can change the look of an entire website by changing just one file!

Each page must include a reference to the external style sheet file inside the <link> element. The <link> element goes inside the <head> section:

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

Internal Style Sheet

An internal style sheet may be used if one single page has a unique style.

Internal styles are defined within the <style> element, inside the <head> section of an HTML page:

body {
    background-color: green;

Inline Styles

An inline style may be used to apply a unique style for a single element.

To use inline styles, add the style attribute to the relevant element. The style attribute can contain any CSS property.

The example below shows how to change the color and the left margin of a <h1> element:

<p style="color:blue;margin-left:30px;">This is a heading.</p>