style.css

* {
    padding: 0;
    margin: 0;
    font-family: "Montserrat", sans-serif;
    scroll-behavior: smooth;
}

body {
    background-color: black;
    color: white;
}

h1 {
    font-size: 3.5rem;
    display: flex;
    text-transform: uppercase;
    justify-content: center;
    padding: 1rem;
}

table {
    border-collapse: collapse;
    width: 40%;
    margin-left:auto;
    margin-right:auto;
    resize: both;
}

th, td {
    border: 2px #666 solid;
    font-size: 24px;
}

td {
    height: 20%;
    position: relative;
}

td .content {
    aspect-ratio: 1 / 1 ;
    table-layout: fixed;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    font-size: 1rem;
    text-shadow: black 1px 0 5px;
}

.active {
    background-image: url("x.png");
    background-size: cover;
}