While we’re on the topic of the styling: you should basically never adjust the letter-spacing on body type. The font designers made the font the way they did on

While we’re on the topic of the styling: you should basically never adjust the letter-spacing on body type. The font designers made the font the way they did on purpose; with the notable exception of all-caps text which does call for increasing letter-spacing, you will make it worse in almost all situations (>99.9%) for almost all body fonts (>99%). I find your chosen letter-spacing of 0.06em decidedly uncomfortable (it’d be too much even for all-caps loosening, that normally calls for something like 0.04em).