I built and battle-tested this across 3 shipped interactive fiction games, then packaged it as a generic single-file template: passages, stat-gated choices, localStorage save/load, and multiple endings — zero external dependencies, fully readable plain HTML/CSS/JS source.
If you want branching fiction without learning a whole new tool, this is a quick drop-in starting point.
https://avagrad.itch.io/story-engine-template
Free to view the demo/source in-browser, small one-time price for the documented template + README authoring guide.