Big Fonts

Try resizing your browser window to see how the font size scales up and down dynamically

This is the code used above

 <h1 style="font-size:8vw;">Big Fonts</h1>
<p style="font-size:2vw;">Try resizing your browser window to see how the font size scales up and down dynamically</p> 
the vw unit means Viewport Width</p> 

If you are familiar with @media CSS property, then this is the same but its my simpler.

 check the screen size is 401px wide or more, set the font-size of <div> to 80px
@media screen and (min-width: 401px) {
  div.example {
    font-size: 80px;
  }
}

check  the screen size is 400px wide or less, set the font-size of <div> to 30px 
@media screen and (max-width: 400px) {
  div.example {
    font-size: 30 px;
  }
}