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

html, body {
  height: 100%;
  background: #2e2e2e;
  font-family: system-ui, sans-serif;
}

main {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

section {
  width: 520px;
}

#info {
  display: flex;
  justify-content: space-between;
  color: white;
  margin-bottom: 10px;
}

#board {
  display: grid;
  grid-template-columns: repeat(20, 1fr);
  aspect-ratio: 1;
  background: #111;
  border: 2px solid #000;
  touch-action: none;
  outline: none;
}

.cell {
  border: 1px solid #222;
}

.snake {
  background: limegreen;
}

.food {
  background: red;
}

#overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  display: none;
  justify-content: center;
  align-items: center;
}

#overlay.active {
  display: flex;
}

#popup {
  background: #111;
  color: white;
  padding: 30px 50px;
  border-radius: 10px;
  text-align: center;
}

#popup button {
  margin-top: 15px;
  padding: 10px 20px;
  font-size: 16px;
  cursor: pointer;
}