Attention Jin: The new design has introduced some rendering inconsistency between the preview and final post. In the beta what you saw in the preview was exactly what was rendered in the final post. However in the new design this is no longer true. It appears that some font sizes are different between the two, e.g. the font employed for bold faces, etc. For example see my post here, and compare the size of the "HINT" in the preview and posted form. This is quite annoying since I go to great effort to control the layout so that the syntax reflects the semantics and such inconsistencies complicate this process.