* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

.grid-demo {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
    padding: 1rem;
}

.img {
    width: 100%;
    height: auto;
    display: block;
}