Stage parity
You author at 1920×1080 and the stage scales to fit, so the canvas already matches the published lesson.
Authoring that stops arguing with the published lesson.
CourseForge gives you a fixed-ratio stage, a slide rail, and an inspector where every value has one obvious home. Slides look finished before you touch a single style.
One styling scope
The lesson theme owns colour, type and rhythm. Slides and blocks inherit it, and inheritance stays visible.
A rail that keeps your place
Reorder, duplicate, hide and delete slides from a persistent rail — with a single undo stack behind ⌘Z.