.mainSection {
    display: flex;
    width:100%;
    justify-content:center;
    background-color:white;
}

.mainSection img {
    object-fit: cover;
    object-position:center;
    width: 100%;
    max-height: 70vh;
}

@media (min-width: 700px) {
    .mainSection img {
        width: 60%;
        max-height: 100vh;
    }        
}