Make Square within Circle Responsive
HTML
<div>
</div>
CSS
div
{
position: relative;
border-radius: 50%;
width: 50%;
height: auto;
padding-top: 50%;
background: #ef8913;
}
div:after {
content: "";
display: block;
position:absolute;
left:0px;
top:0px;
width: 50%;
height:auto;
margin: 20% 25%;
padding-bottom: 50%;
padding-top: 10%;
background: gold;
}