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

body {
  min-height: 100vh;
  min-width: 100vw;
  display: flex;
  justify-content: center;
  align-items: center;
  background: url('../images/body.jpg') center center/cover;
}

#game-board {
  width: 90vh;
  height: 90vh;
  position: relative;
  background: url('../images/wp2409719.jpg') center center/cover;
  display: grid;
  grid-template-columns: repeat(21, 1fr);
  grid-template-rows: repeat(21, 1fr);
}
#game-board::before {
  content: '';
  background-color: #02070E;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0.5;
}
.snake {
  background-color: green;
  border: 0.25vmin solid black;
}
.food {
  background-color: greenyellow;
  border: 0.25vmin solid black;
}