A Type Scale That Holds Up on Real Content
Modular scales look beautiful in a specimen and fall apart the moment an editor writes a nine-word heading. Here's the fluid scale we use instead.

The classic advice is to pick a ratio and multiply. That works until real content arrives with headings twice as long as your sample text.
Fluid, but clamped early
We use clamp() on four sizes only — display, headline, subhead, body — and cap the upper bound well below the viewport maximum. Anything larger gets chosen deliberately per template rather than generated.
Test with the worst case
Our specimen files include the longest heading from the client's existing site and the shortest. If the scale survives both, it ships.
Design for the second-longest heading. The longest one you'll edit; the second-longest will slip through.