:root {
  --bg: rgb(32, 28, 28);
  --text: rgb(228, 211, 211);
  --cell1: rgb(213, 188, 188);
  --cell2: brown;
}

* {
  box-sizing: border-box;
}

body {
  padding: 0;
  margin: 0;
  min-height: 100vh;

  display: flex;
  justify-content: center;
  align-items: center;

  background-color: var(--bg);
}

.board {
  display: grid;
  aspect-ratio: 1 / 1;
  width: max(300px, min(90vmin, 550px));
  border: 3px solid var(--text);
}

.cell {
  display: flex;
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
}

.white {
  background-color: var(--cell1);
}

.black {
  background-color: var(--cell2);
}

.knight {
  width: 100%;
  cursor: grab;
  user-select: none;
  -webkit-user-drag: none;
  -moz-user-drag: none;
  -ms-user-drag: none;
  user-drag: none;
  touch-action: none;
}

.knight-copy {
  position: absolute;
  pointer-events: none;
}

.cell-under-knight {
  border: 2px solid yellow;
}

.path {
  border: 3px solid yellow;
}

.goal {
  border: 3px solid rgb(116, 221, 116);
}