h1 {
  color: yellow;
  text-shadow: 0 0 3px #A70096;
}

div {
  color: white;
  text-shadow: 0 0 3px #A70096;
}

body {
  background-image: url("https://c.tenor.com/D5wTf-flUAIAAAAC/american-psycho-dance.gif");
  background-size: 500px;
  position: relative;
  animation: wave 1s infinite;
  animation-direction: normal;
  animation-timing-function: ease-in-out;
}

@keyframes wave {
  0%   {transform: rotate(-1deg);}
  50%  {transform: rotate(1deg);}
  100% {transform: rotate(-1deg);}
}