There is a weird CSS quirk in some browsers that cause an element that has a top margin to collapse that margin like it has no margin applied at all (more about this).
As a rule of thumb when you build the layout please avoid vertical and top margins. Add spacing spacing between 2 elements by applying a margin bottom to the first so it will push the element under it and avoid margin top totally.
Also if you make a row and want to color the background of the row while having space from the margin of the row and the containing elements use padding vertical and not margin vertical.
Learn how to install and configure the framework. See how WPS-Prime uses it’s own custom components/elements to construct with Visual Composer.