Acquia Cohesion renames to Site Studio from version 6.2. Tell me more.
Base styles are CSS styles for HTML elements.
We recommend using decimals e.g. 1.3 as this makes the line height relate to your font size.
The 'Range' in the menu list item element sets which list items at the current level the settings should apply to.
You don’t have to add units unless you want to use a specific unit or you’re adding Custom CSS properties.
It depends on the font you are using. If you have individual files for each font, you should upload zip files for each weight.