body {
  background: linear-gradient(0deg, #6139a5 0%, #4570df 100%);
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 0;
  padding: 0;
}

.logo {
  display: block;
  margin: 0 auto 20px;
}

#game_board {
  width: 240px;
  height: 480px;
  border: 5px solid #3e5eba;
  margin: 0 auto;
  position: relative;
  background: repeating-linear-gradient(
      rgba(22, 28, 67, 0.8),
      rgba(22, 28, 67, 0.8) 20px,
      rgba(23, 27, 63, 0.8) 20px,
      rgba(23, 27, 63, 0.8) 40px
    ),
    repeating-linear-gradient(
      90deg,
      rgba(22, 28, 67, 0.8),
      rgba(22, 28, 67, 0.8) 20px,
      rgba(23, 27, 63, 0.8) 20px,
      rgba(23, 27, 63, 0.8) 40px
    );
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.6);
}

.block {
  width: 24px;
  height: 24px;
  border: 1px solid black;
  position: absolute;
  box-shadow: inset 3px 3px 0 rgba(255, 255, 255, 0.5);
}

.ghost {
  width: 24px;
  height: 24px;
  border: 1px solid black;
  position: absolute;
  box-shadow: inset 3px 3px 0 rgba(255, 255, 255, 0.3);
}