*{ box-sizing:border-box; }
body{ margin: 3vmin;}
#blue{ 
  width: 94vmin; 
  height:94vmin; 
  max-width:600px; 
  max-height:600px; 
  margin:0 auto;
  background-color: blue; 
  position:relative;
}
#green{ 
  background-color:green;
  position:absolute;
  left: 2vmin; 
  top: 10vmin; 
  width: 32vmin; 
  height: 75vmin;
}

#red{ 
  background-color:red;
  position:absolute;
  left: 60vmin; 
  top: 10vmin; 
  width: 32vmin; 
  height: 75vmin;
  border-radius: 50%;
}