body {
  background: #2980b9; /* fallback for old browsers */
  background: -webkit-linear-gradient(
    to right,
    #2c3e50,
    #2980b9
  ); /* Chrome 10-25, Safari 5.1-6 */
  background: linear-gradient(
    to right,
    #2c3e50,
    #2980b9
  ); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
  position: relative;
  min-height: 100vh;
}

footer {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
}
@media screen and (max-width: 800px) {
  img {
    width: 100%;
    height: auto;
  }
}