body {
  margin: 0;
  padding: 0;
  display: grid;
  place-items: center;
  min-height: 100vh;
  background-color: #333;
}

#game-area {
  width: 80vmin;
  height: 80vmin;
  background-color: #8bc34a;
  border: 2px solid #555;
  overflow: hidden;
  position: relative;
  container-type: inline-size;
}

.snake-segment {
  width: 5%;
  height: 5%;
  background-color: #000;
  border: 1px solid #8bc34a;
  position: absolute;
  border-radius: 2px;
}