html,
body {
  display: flex;
  flex-direction: column;
  height: 100%;
  width: 100%;
  background: rgb(150,150,150);
  background: linear-gradient(90deg, rgba(150,150,150,1) 0%, rgba(112,110,110,1) 25%, rgba(85,83,83,1) 47%, rgba(112,110,110,1) 71%, rgba(150,150,150,1) 100%);
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  background-attachment: fixed;
}