:root {
    --cell-size: 150px;
}

html, body {
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    font-family: 'Courier New', Courier, monospace;
}

main {
    flex: 1;
    align-content: center;
}

#game {
    width: calc(var(--cell-size) * 3);
    height: calc(var(--cell-size) * 3);
    border: 2px solid transparent;
    border-collapse: collapse;

    td {
        width: var(--cell-size);
        height: var(--cell-size);
        border: 1px solid grey;
        position: relative;
        text-align: center;
        vertical-align: middle;
        font-size: calc(var(--cell-size) / 2);

        &.clear {
            cursor: pointer;

            &:hover {
                background-color: lightgray;
            }
        }

        &.x::after {
            content: "\274c";
        }

        &.o::after {
            content: "\2b55";
        }
    }

    &.disabled {
        pointer-events: none;
    }
}

.hidden {
    display: none;
}

#result {
    width: 100%;
    height: 100%;
    position: absolute;
    left: 0;
    top: 0;
    flex-direction: column;
    align-content: center;
    text-align: center;
    background-color: rgba(255, 255, 255, .8);
    font-size: 2em;

    button {
        font-size: inherit;
    }
}