For Dan. This site shows the HS Chemistry course as the Timeback player presents it — the same cards, in the same order, with the player’s look. One page per unit; everything is open, so you scroll rather than click.

Figures are our deterministic SVG renders drawn from the specs. David’s production raster images will be swapped in when supplied.

Intro and summary videos link out to David’s player (they open in a new tab).

Checkpoints here show all the options with the key marked, because this is a review copy. Students see shuffled options and must retry until correct; a correct answer replaces the options with the green explanation panel.

At each topic boundary sits an End of Topic Test — five interchangeable forms, delivered separately, so this site marks where each test falls rather than showing its items.