The @keyframes at-rule sets the value of properties at different points during an animation, so instead of defining how each property should behave at each frame of an animation, we set its keyframes, and CSS will figure out (i.e., interpolate) the values between them.

@keyframes spin {
  from {
      transform: rotate(0deg);
  }
  to {
      transform: rotate(720deg);
  }
}