BODY {
  margin: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
}
#box {
  display: flex;
  align-items: center;
  justify-content: center;
  background: white;
  height: 100%;
}
#int {
  display: inline-block;
  text-align: center;
}
H1 {
  font-size: 10vw;
  margin: 0;
  padding: 0;
  font-family: sans-serif;
  background: white;
  color: black;
}
H1:before {
  content: '';
  mix-blend-mode: screen;
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  filter: blur(20px);
  background-image: repeating-linear-gradient(0deg, #F00, #F00 50%, #800 51%, #000 100%);
  background-position: 0 -2vw;
  animation: bganim 2s ease-in-out 0s infinite alternate both;
}
@keyframes bganim {
  from {
    background-position: 0 -2.5vw;
  }
  to {
    background-position: 0 1.5vw;
  }
}
P {
  font-size: 2.2vw;
  margin: 0;
  padding: 0;
  font-family: sans-serif;
  background: white;
  color: black;
  mix-blend-mode: multiply;
}