<!DOCTYPE html> <html> <head> <style type="text/css"> #red { height: 20px; background-color: red; } #green { height: 20px; background-color: green; } #blue { height: 20px; background-color: blue; } .margin { height: 20px; } </style> </head> <body> <div id="red"></div> <div class="margin"></div> <div id="green"></div> <div class="margin"></div> <div id="blue"></div> </body> </html>
