Rotating cells

<main>
    <div></div><div></div><div></div><div></div>
    <div></div><div></div><div></div><div></div>
    <div></div><div></div><div></div><div></div>
    <div></div><div></div><div></div><div></div>
</main>

html {
  margin: 0;
  height: 100vh;
  background-color: blue;
}
html, main {
  display: flex;
  justify-content: center;
  align-items: center;
}
main {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  width: 100vw;
  height: 100vw;
}
div {
  margin: 3vw;
  padding: 1vw;
  background-color: springgreen;
  animation: rotate 5s infinite linear;
}
@keyframes rotate {
  from {
    transform: rotate(0);
  }
  to {
    transform: rotate(360deg);
  }
}