<div id="content">
  <h1>CSS circles using border radius</h1>
  <div class="circle blue">Blue</div>
  <div class="circle green">Green</div>
  <div class="circle red">Red</div>
  <p class="feedback">Feedback welcomed via Twitter - <a href="http:/twitter.com/tomdurkin">@tomdurkin</a></p>
</div>  
body {
  font-family: "open sans", sans-serif;
  background: #f1f1f1;
}
#content {
  margin: 40px auto;
  text-align: center;
  width: 600px;
}
#content h1 {
  text-transform: uppercase;
  font-weight: 700;
  margin: 0 0 40px 0;
  font-size: 25px;
  line-height: 30px;
}
.circle {
  width: 200px;
  height: 200px;
  line-height: 200px;
  border-radius: 50%; /* the magic */
  -moz-border-radius: 50%;
  -webkit-border-radius: 50%;
  text-align: center;
  color: white;
  font-size: 16px;
  text-transform: uppercase;
  font-weight: 700;
  margin: 0 auto 40px;
}

.blue {
  background-color: #3498db;  
}
.green {
  background-color: #16a085;
}
.red {
  background-color: #e74c3c;
}
.feedback {
  font-size: 14px;
  color: #b1b1b1;
}
/* Feedback welcomed via Twitter - @tomdurkin 
   Enjoy! ;)
*/

External CSS

  1. https://fonts.googleapis.com/css?family=Open+Sans

External JavaScript

This Pen doesn't use any external JavaScript resources.