body {
  background-color: black;
  margin: 0;
  padding: 0;
}

.block {
  position: relative;
  margin: 10% auto 0;
  width: 50%;
  height: 300px;
  background: linear-gradient(0deg, black, rgb(44,44,44))
}

.glow::before, .glow::after {
  content: "";
  position: absolute;
  left: -2px;
  top: -2px;
  background: linear-gradient(45deg , #e6fb04, #ff6600, #00ff66, #00ffff,
  #ff00ff, #ff0099, #6e0dd0, #ff3300, #099fff);
  background-size: 400%;
  width: calc(100% + 5px);
  height: calc(100% + 5px);
  z-index: -1;
  animation: animate 20s linear infinite;
}

@keyframes animate {
  0% {
    background-position: 0 0;
  }
  50% {
    background-position: 400% 0;
  }
  100% {
    background-position: 0 0;
  }
}

.glow::after{
  filter: blur(40px);
}

h5 {
  font-size: 25px;
}
h4 {
  font-size: 27px;
}
h3 {
  font-size: 30px;
}

@media (max-width: 1079px) {
  h5 {
    font-size: 23px
  }
}

@media (max-width: 815px) {
  h5 {
    font-size: 20px
  }
}

@media (max-width: 615px) {
  h3 {
    font-size: 18px
  }
  h4 {
    font-size: 16px
  }
  h5 {
    font-size: 18px
  }
}