This is H1

This is H2

This is H3

This is a regular paragraph. This is a regular paragraph. This is a regular paragraph. This is a regular paragraph. This is a regular paragraph. This is a regular paragraph. This is a regular paragraph. This is a regular paragraph. This is a regular paragraph. This is a regular paragraph. This is a regular paragraph. This is a regular paragraph.

CSS:

body {font-size: 1em; font-family: arial, sans-serif;}
h1   {font-size: 1em;}
h2   {font-size: .9em;}
h3   {font-size: .8em;}
p    {font-size: .7em;}