.container {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

.possible {
    width: 10rem;
    height: 10rem;
    margin: 1rem;
    border: 0.5rem;
    border-style: solid;
    border-color: rgb(207, 207, 207);
    border-radius: 0.75rem;
    transition: opacity 0.3s;
}

.number {
    font-family: "Ubuntu";
    color: rgb(207, 207, 207);
    position: relative;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

body, html {
    background-color: rgb(20, 20, 20);
}