body {
    margin:0;
	display:flex;
	height:100vh;
	align-items:center;
}

.main-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);

    margin: 0 auto;

    width: 30rem;
    height: 40rem;
}

.slot {
    border: 1px solid rgb(0, 0, 0);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    cursor: pointer;
}

.slot img {
    display: none;
    width: 100%;
    height: 100%;
}