body {
  width: 100%;
  height: 100vh;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background-size: 300% 300%;
  background-image: linear-gradient(
        -45deg, 
        rgba(59,173,227,1) 0%, 
        rgba(87,111,230,1) 25%, 
        rgba(152,68,183,1) 51%, 
        rgba(255,53,127,1) 100%
  );  
  animation: AnimateBG 20s ease infinite;
}

@keyframes AnimateBG { 
  0%{background-position:0% 50%}
  50%{background-position:100% 50%}
  100%{background-position:0% 50%}
}


.content {
  width: 1200px;
  max-width: 100%;
  margin: auto;
  text-align: center;
}
img {
  max-width: 100%;
  display: inline-block;
}