page based load epub when changing font

Question

I am doing ebook reader app like as iBooks. I have succesfully read a .epub file. But my problem is:-

I have to add Font size increase and decrease and font changing fun

Answer 1

first to increase font size you need to give font size in em . before using em you need to give the body font-size:62.5% and for the elements inside div give font-size like 1.2em (which will act as 12px). so when you want to increase any Div's font-size you just have to increase font size of body by 10%. And you don't need to calculate characters for adjusting pages and this is not good practice for if you are making responsive book. use column property off css, let css handle flow of your pages. See below link for font size and flowable html structure

js fiddle

Js Fiddle

and also see "readium js for chrome". which will give you idea about how to render epub file on browser