<!DOCTYPE html> <html> <head> <style type="text/css"> #parent { width: 200px; } #block1 { height: 40px; margin-bottom: 10%; background-color: green; } #block2 { height: 40px; margin-top: 25%; background-color: green; } </style> </head> <body> <div id="parent"> <div id="block1"></div> <div id="block2"></div> </div> </body> </html>
