This program will teach you on how to use media queries using CSS3.
One way to use media queries is to have an alternate CSS section right inside your style sheet.
The following example changes the background-color to lightgreen if the viewport is 480 pixels wide or wider (if the viewport is less than 480 pixels, the background-color will be pink):
1. Download the source code.
2. Extract the compressed folder.
3. Open the index.html in any browser
This is just a simple program any updates or constructive criticism will be accepted.