On the reading screen, touch the middle of the screen to display the menu bar at the bottom. Touch "" to adjust the font size, font style, line spacing, and alignment mode. The detailed steps are shown below:

1. Drag the slider on to adjust the font size.
2. Drag the slider on to adjust the line spacing.
3. Touch , and select the font type that you wish to use. The app will automatically download and switch to this font.
4. Touch to switch the alignment mode of the text.