#container
{
  position: absolute;
  top:0;
  left:0;
  width:100vw;
  height:100vh;
  margin:0;
  display:flex;
  justify-content:center;
 align-items:center; 
}

.content
{
  width: 500px;
    height: 500px;
    border: solid blue;
  border-radius: 50%;
  overflow: hidden;
  background-image:url("https://projects.codecraftworks.com/web/eOe9t0sw4NhTKoegnJm4/assets/dusan-veverkolog-vyd2f5MCxeM-unsplash (3).jpg");
  background-repeat: no-repeat;
  background-position: center;
  background-size:cover;
 
}