I have just started using quarto book instead of bookdown. I am just playing with the default setup for now and trying to control the width of each column of the 3-column default layout. This was done relatively easily with css in bookdown... Can't seem to find to way to achieve this with quarto.
quarto seems almost infinitely customizable, like ggplot. That also means it can be a ton of work finding where you need to customize. There are a lot of yaml options but these won't adjust width of anything but images. But partial templates allow going in with complete control. The opportunities for missteps are there, so practice with toy books are indicated.
I believe this is a new feature that is available in 1.3 the next release (already available as pre-release).
See release note at Quarto – Download Quarto
and specific page for this new feature : Redirect