HTML 및 CSS를 사용하여 상자에서 Fluid Animation 만들기

<div class="box"></div>

:root {
  --bg-grey: #eee;
  --bg-dark: #303032;
}

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

html, body {
  height: 100%;
}

body {
  display: grid;
  place-content: center;
  background-color: #fff;
}

.box {
  width: 10rem;
  height: 10rem;  
  border: 2px solid var(--bg-dark);
  background-color: var(--bg-dark);

  position: relative;
  overflow: hidden;
}

.box::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width:100%;
  height: 100%;
  background-image: url("https://upload.wikimedia.org/wikipedia/commons/5/53/Google_\"G\"_Logo.svg");
  background-size: cover;
  background-position: 100%;
}

.box::after {
  content: '';
  position: absolute;
  bottom: -50%;
  left: -50%;
  border-radius: 45%;
  width: 180%;
  height: 180%;
  background-color: var(--bg-grey);

  animation: spin 4s ease-in-out infinite;
}

@keyframes spin {
  from {
    transform: translateY(0) rotate(0);
  }
  to {
    transform: translateY(-100%) rotate(500deg);
  }
}