[FAQ] Why the apostrophes are full-width?
It happens when the EPUB uses ’ (U+2019 RIGHT SINGLE QUOTATION MARK) rather than ' (U+0027 APOSTROPHE) for apostrophes, and when the font (maybe the device default font) is CJK fonts, it will render the ’ (U+2019 RIGHT SINGLE QUOTATION MARK) full-width. Please try to select another font like Serif or Sans-serif, or download your favorite font to display the content.