font-size: 0 creates problems for content inside pages

[zhenjl]

Currently we use display: inline-block for laying out pages. However, to remove the small gap between each inline-block we need to use font-size: 0. The problem is that font-size is inherited by all the children below that, which means the user will have to explicitly set font-sizes for all elements inside the pages. This is annoying and should be fixed.