Set top gaps between block elements.
Mobi.css provides three classes, .top-gap-big, .top-gap and .top-gap-0 to easily override the top margin.
Setting an element to .top-gap-big will make it's margin-top to 30px, while .top-gap is 15px and top-gap-0 is 0.
p.top-gap-0
<div class="top-gap">div.top-gap</div>
<p class="top-gap-0">p.top-gap-0</p>
<section class="top-gap-big">section.top-gap-big</section>
We think when you set .top-gap* to an element, you are very sure that the margin-top of this element should be the value you set.
So both .top-gap-big, .top-gap and .top-gap-0 are set margin-top with !important.
This can avoid margin-top being overided.