html, body {
  margin: 0;
}

html {
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  height: 100%;
}

body {
  overflow: hidden;
  height: inherit;
}

#focus {
  font-size: 1rem;
  width:20px;
  text-align:center;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%,-50%);
  color: white;
  border:2px solid white;
  border-radius:15px;
}