*, *::before, *::after {
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
}

body {
    background-color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0;
    font-size: 7.5vmin;

}

#container {
    display: flex;
    flex-direction: column;
    height: 100vmin;
}

#score-bar, #back-to-home {
    margin: 0;
    padding: 0;
    background-color: #ccc;
    width: 90vmin;
    height: 10vmin;
    border-radius: 1vmin;
    text-align: center;
}
#score-bar {
    border-bottom: 0.5vmin solid #333333;
}
#back-to-home {
    border-top: 0.5vmin solid #333333;;
}

#back-to-home > a, a:hover, a:focus, a:active {
    text-decoration: none;
    color: inherit;
}

#game-board {
    border-top: 0.5vmin solid #333333;
    height: 90vmin;
    width: 90vmin;
    display: grid;
    grid-template-columns: repeat(var(--grid-size), var(--cell-size));
    grid-template-rows: repeat(var(--grid-size), var(--cell-size));
    background-color: #ccc;
    gap: var(--cell-gap);
    border-radius: 1vmin;
    padding: var(--board-gap);
    position: relative;
    animation: show 200ms ease-in-out;
    touch-action: none; /* stop all */
    justify-content: center


}

.cell {
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 1vmin;
    --lightness: 20%;
    --text-lightness: 80%;
    --hue: 20;
    --saturation: 0%;
    background-color: hsl(var(--hue), var(--saturation), var(--lightness));
    color: hsl(200, 25%, var(--text-lightness));
    font-weight: bold;
    animation: show 200ms ease-in-out;
    transition: 170ms ease-in-out;
}


@keyframes show {
    0% {
        opacity: .5;
        transform: scale(0);
    }
}