Bootstrap 4 has a slew of classes devoted to margins and padding. You can take advantage of these in spacing ANY block in this theme.

We are going to use padding. Here are the classes:

• pt-1: 
• pt-2:
• pt-3:
• pt-4:
• pt-5:
• pb-1:
• pb-2:
• pb-3:
• pt-4:
• pb-4:
• pb-5:
• pt-md-1:
• pt-md-2:
• pt-md-3:
• pt-md-4:
• pt-md-5:
• pb-md-1:
• pb-md-2:
• pb-md-3:
• pb-md-4:
• pb-md-5:

There are a lot more that correspond with this general format. 'pt' means 'padding-top' and the number (1 thru 5) indicates the amount which is nonlinear. I've listed the base and the medium but there are 3 other breakpoints like this:

• pb-lg-3
• pt-xl-2
• pt-sm-3

Corresponding to Large, Extra Large and Small screens (the base is very narrow, basically 0 to 570 pixels). You can use any of these as custom classes.