html, body {
    background-image: url(https://w.wallha.com/ws/4/Vlw87L9q.png);
}

main.grid-container {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    grid-gap: 20px;
    padding: 20px;
}

.category {
    border: 1px solid #ccc;
    padding: 20px;
}

.category h2 {
    margin-top: 0;
}

.game {
    margin-top: 20px;
    text-align: center;
}

.game img {
    width: 600;
    height: 400;
}