* { box-sizing: border-box; }


#outer{
  width: 70vmin;
  height: 70vmin;
  margin: 0 auto;
  background-color: blue;
  padding: 15vmin 11vmin 15vmin 11vmin;
  
}


#secondring{
  background-color: navy;
  padding: 15vmin 7vmin 15vmin 7vmin;
  height: 50vmin;
    
  

}



#innersquare{
  background-color: darkgreen;
  padding: 15vmin 10vmin 10vmin 11vmin;
  height: 30vmin;

  

}