We have here circles on our main page. We have managed to make it responsive in terms of resizing the screen, eg 992px, 768px, etc. Here's our CSS code:
.circle { 
   position: relative; 
   display: inline-block; 
   width: 100%; 
   height: 0; 
   margin-top:10%; 
   margin-left:-15%; 
   padding-bottom:120%; 
   -moz-border-radius:50%; 
   -webkit-border-radius:50%; 
   border-radius:50%; 
   background-color: white; 
   -ms-transform: rotate(20deg); /* IE 9 */ 
   -webkit-transform: rotate(20deg); /* Chrome, Safari, Opera */ 
   transform: rotate(20deg);   
}
The problem is, they are not being responsive when the screen is being zoomed in or out.
 
    