Spacing issue

Hi! I'm hoping someone can help to provide instructions on how to add custom code to solve for the very large gap of space under the third link on this page (http://cmuscato.com/samples), and above the gallery section. The space between is very large.

Thanks so much! 

Add to Design > Custom CSS

/* Mobile Samples Top space */
@media screen and (max-width:767px) {
[data-section-id="6451af4d50b00a2a3f848466"] {
    min-height: unset !important;
    height: 40vh;
}
}