Vertical Metrics Explained: hhea, typo, win, and USE_TYPO_METRICS
Why the same font can get a different line height on macOS and Windows: the three sets of vertical metrics, the USE_TYPO_METRICS flag, and what you can do in CSS.
Typography
Font guides in the Typography category
Variable Fonts on the Web: Axes, font-weight Ranges, and font-variation-settings
How to load a variable font with @font-face, control its axes with normal CSS properties, and use font-variation-settings only where you need it.
OpenType Features in CSS: font-variant or font-feature-settings?
Turn on tabular figures, small caps, fractions, and stylistic sets in CSS. When to use the font-variant properties and when font-feature-settings is the only option.