When you create a page with Divi you will notice that by default, it has quite a generous amount of padding space. 


Here is the example before.



What we are looking is tighten this up and align. We want to make sure that the button is better aligned on desktop only as forcing extra padding can cause it to disappear on mobile or tablet sized screens. We did this by adding the below code to the custom CSS box in Divi theme options:

.home .et_pb_section,.home #main-content .et_pb_section { padding: 0; }
.home .et_pb_section,.home #main-content .et_pb_section .et_pb_row{ padding: 0; width: 100%; }

@media only screen and (min-width: 1024px) {
.et_pb_row .et_pb_button {
position: relative;
top: 60px;
}
}

The end result is like this below. I vertically aligned the button as from this post.