body{
    width: 100%;
    height: 100%;
    min-height: 100vh;
    background: #000;
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0;
    padding: 0;
}
.main-pic{
    width: 100%;
    max-width: 600px;
}
@media(max-width: 767px){
    .main-pic{
        max-width: 100% !important;
    }
}