I have a normalize/reset, why do I need this?
This isn't meant to replace a normalize or a reset. Keep using your normalize and reset.
When do I use this?
After you've put your normalize/ reset in place, and when you're looking for a starting place for your brand. This attempts to provide some sort of baseline style for all of the typographical elements.
what can I change?
Anything and everything. It's a baseline. But if you want to know what to change first, start with the
html and then move on to colors.
What about the HTML file?
The HTML file is an attempt to use all of the inline, content-flow, and otherwise odd/obscure semantic elements appropriately. Semantics are hard.