#brown { height: 200em; width: 200px; background-color: brown;} #green { height: 50px; width: 50px; margin-left: 50px; background-color: green;} #blue { height: 50px; width: 50px; background-color: blue;} <div id="brown" class="box"><div id="green" class="box"></div><div id="blue" class="box"></div></div>