* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  background-image: url(images/stars1.gif);
  height: 100%;
  width: 100%;
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

body {
  width: 100%;
  height: 100vh;
}

h1 {
  text-align: center;
  margin-top: 3rem;
  text-transform: uppercase;
  letter-spacing: 1rem;
  font-size: 4rem;
  color: #fff;
}

.wrapper {
  width: 30rem;
  aspect-ratio: 1;
  border-radius: 50%;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.wrapper::before {
  content: '';
  position: absolute;
  width: 100%;
  height: 100%;

  border-radius: 50%;
  z-index: 10;
  box-shadow: -0.5rem -0.2rem 2rem #444, 0.5rem 0.2rem 2rem #444;
}

.earth {
  width: 100%;
  aspect-ratio: 1;
  position: absolute;
  border-radius: 50%;
  animation: earthAnim 25s infinite linear;
}

.day {
  background-image: url(images/earth-day.jpg);
}

.night {
  background-image: url(images/earth-night.jpg);
  clip-path: polygon(0 0, 50% 0, 50% 100%, 0 100%);
}

@keyframes earthAnim {
  0% {
    background-position: 0 center;
  }

  100% {
    background-position: 120rem center;
  }
}