You already think in the right abstractions.
Figma trains you to think about structure, hierarchy, constraints, components, variables, and states. These aren't Figma concepts — they're universal design concepts that HTML and CSS have their own answers to.
This path doesn't ask you to forget what you know. It asks you to recognise the translations: Auto Layout → Flexbox & Grid, Variables → Custom Properties, Components → Web Components or BEM classes, Constraints → CSS Box Model.