.grid-container {
  position: fixed;
  top: 4em;
  left: 0;
  width: 100vw;
  height: 100vh;
  display: grid;
  grid-template-columns: repeat(4, 1fr); 
  grid-template-rows: repeat(4, 1fr); 
  z-index: -10;
}

.grid-item {
  display: flex;
  justify-content: center;
  align-items: center;
  opacity: 0;
}

svg {
  width: 100%;
  height: auto;
}

/* Keyframes for colour change */
@keyframes gridColorChange {
  0% {
    opacity: 0;
  }
  25% {
    opacity: 0.2;
  }
  50% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}

/* Apply to each span within the h1 */
.grid-container > .grid-item {
  display: inline-block;
  width: 100%;
  height: 100%;
  animation: gridColorChange 24s infinite ease-in-out;
}

/* Offset each letter's animation by a small amount */
.grid-container div:nth-child(1) {
  animation-delay: 0s;
}
.grid-container div:nth-child(2) {
  animation-delay: 4s;
}
.grid-container div:nth-child(3) {
  animation-delay: 8s;
}
.grid-container div:nth-child(4) {
  animation-delay: 12s;
}