Can the background and font size of e-books be adjusted?

E - book background: For EPUB e - books, you can adjust the background theme, while PDF e - books do not support theme background adjustment.

E - book font size: On Android devices, you can click the three dots in the upper - right corner and select [Adjust Font]. iOS devices do not support font adjustment. This method of adjusting the font is only effective for EPUB - format e - books and does not work for PDF e - books. For PDF e - books, you can use two - finger gestures to zoom in and out. Also, when the e - book is not in the normal proportion, you cannot turn the pages. After restoring the original proportion, the normal left - right page - turning function will be restored.