Originally Posted by vidgej
Hi Dale! Thanks for your answer. However, considering the fact that I'm a newbie on Ebook readers or ebooks itself (including tech. words and jargon), please explain what "explode the file and change the content to not specify the font size" means. sorry for the inconvenience. thanks thanks thanks!
It isn't really easy. You need to convert the mobi file back to its source. See https://www.mobileread.com/forums/forumdisplay.php?f=168
and look over the stickies. These are perl scripts to manipulate mobi files but some are compiled for windows. Since you are really talking about mobi format which has nothing to do with Astak reader you will get better help if you move your questions over to the forum specifically designed to answer questions about mobi format. That is where the experts live.