Text settings

Free. Everyone gets this.

Press Aa in the Reader toolbar to make the page look the way you like.

The Aa panel open under the toolbar

What you can change

Font. Serif (the book’s own look), Sans-serif, Easy-read, or Match my Obsidian theme. Easy-read uses Atkinson Hyperlegible, a font made to be easy to read, including for people with dyslexia.
Text size. Press A− or A+ to make the text smaller or bigger.
Line spacing. Tight, Normal, Relaxed or Loose.
Margins. Narrow, Normal or Wide.
Justify text. Lines the text up evenly on both sides. It’s off to start with.
Page look. Auto, Dark or Light. Auto follows your computer’s light or dark setting.

Your choices apply to every book, and Reading Vault remembers them.
Changes show straight away, and you stay on the same text you were reading.
For PDFs, only Page look and Page size work. A PDF’s pages are a fixed picture of the file, so fonts and sizes can’t change.
Page size (PDFs). Whole page (the default) shows each page without scrolling. Fit width makes the page as wide as the Reader; scroll down to read the rest.