body {
  font-family:monospace;
  font-weight:bold;
  width: 100%;
  height: 100vh;
  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;
  }
  .mainBox {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  .textBox {
    width: 30%;
    text-align: center;
  }
  h1 {
    color: #fff;
  }
  img {
    width: 50%;
    border: 1px solid #fff;
  }

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