.center {
  margin: 0;
  position: absolute;
  top: 50%;
  left: 50%;
  margin-right: -50%;
  transform: translate(-50%, -50%);
}

body {
  background-color: #303030;
  background-size: 100% 100%;
  background-image: url("assets/load.png");
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-position: center;
}