body{text-align:center;font-family:Arial,sans-serif;background:#fff;color:#000}#puzzle-container{display:grid;grid-template-columns:repeat(5,80px);grid-gap:5px;margin:30px auto;width:430px}.tile{width:80px;height:80px;background-color:#000;color:#fff;font-size:24px;line-height:80px;text-align:center;cursor:pointer;border-radius:6px;user-select:none;transition:all .2s}.tile.empty{background-color:#fff;cursor:default}