Hello Niva,
I don’t see an issue with the responsivity, could you tell me the exact resolution in which the website is cut off?
Regarding mobile, try setting a customized CSS Class for the first section of the page (in the Page Builder > the first section’s settings > CSS Classes)
For example the class: mobile-page
Then in the Customizer > Live CSS insert the following code:
@media (max-width:768px) {
.mobile-page{padding-top:0 !important;}}