In-content pages and the browser chrome follow different type scales due to the chrome relying on operating systems' font sizing, while in-content pages follow the type scale set by the design system.
We set font: message-box at the root of common-shared.css and global.css stylesheets so that both in-content and the chrome can have access to operating system font families.
We also don't specify line height units and rely on the default.
Heading font size
The chrome of the browser does not include heading variations. The following tokens only apply to in-content (about:) pages.
MacOS
Windows
Ubuntu
Body font size
MacOS
Windows
Linux
Font weight