body {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
}

.border {
  position: fixed;
  top: 0;
  left: 0;
  border: 7px solid #80DEEA;
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}