index.css

html {
    min-width: 100vw;
    min-height: 100vh;
}

body {
    background: linear-gradient(135deg,#ffffff, #abbaab);
    background-repeat: no-repeat;
    width: 100%;
    height: 100%;
}

h1 {
    font-family: cursive;
}

.super-board {
    border-collapse: collapse;
    border-style: hidden;
}

.super-board-row > td {
    border: 5px solid black;
}

.super-board-row table {
    border-collapse: collapse;
    border-style: hidden;
}

.super-board-row table td {
    border: 1px solid black;
    width: 2rem;
    height: 2rem;
    max-width: 2rem;
    max-height: 2rem;
}

.super-board-row > td button {
    width: 100%;
    height: 100%;
    background-color: Transparent;
    background-repeat: no-repeat;
    border: none;
    box-sizing: border-box;
    cursor: pointer;
    overflow: hidden;
    outline: none;
}

.super-board-row > td button:disabled {
    cursor: not-allowed;
}

.blue-taken {
    background-color: rgba(0, 0, 255, 0.2);
}

.red-taken {
    background-color: rgba(255, 0, 0, 0.2);
}

.tied {
    background-color: rgba(255, 255, 0, 0.2);
}

.unplayable {
    background-color: rgba(0, 0, 0, 0.2)
}