Super cool! I'm just starting to get into very basic html/web-dev, so not only were the 'hidden' messages in your html cute to read via inspect element, but seeing that this was all contained in a single javascript file was pretty eye-opening for me! thanks for making it open source, I'll be sure to give it another look once I get to that.

My only suggestion, alongside everyone else's agreement that text should be faster/selectable: how about trees, so that you can keep track of all the nested parts? for example, when I select any of the parts of the drivetrain, perhaps a tree/breadcrumb element would say bike/drivetrain/chainring. Similarly, maybe any other parts that get mentioned in descriptions could be hyperlinks, which can take you instantly to the relevant part.

Super cool and fun presentation! I've had thoughts about doing something similar but for old film projectors. I'll let you know if that ever ends up happening, maybe I could give you a shoutout!