.intro-txt {
    width: 680px;
    margin: 0;
}
.intro-img {
    width: 470px;
}
.view-media {
    margin-top: 60px;
}
@media (max-width: 750px) {
    .intro-txt {
        width: 100%;
        margin-top: 20px;
    }
    .picture-item {
        width: 48%;
        margin-bottom: 4%;
    }
}