Maybe many guys out there, when they start to learn how to use CSS, don’t know that when two or more vertical margins meet in a layout, they collaps to form a single margin. Which will be the height of this margin? simple.. the larger of the two margins.
This is true only for block boxes, in the normal flow of the document (not for inline, floated, absoluted positioned boxes..).
This is the case for example of two elements vertically aligned:
The result will be the following:
