Ctrl 3) controls how your course looks to learners. It has nothing to
do with how the Compose editor looks — that lives in Settings ▸ Appearance.
Design tab → what learners see. Settings ▸ Appearance → what you see while authoring. Changing
Compose to dark mode does not make your course dark.
Theme presets
Six built-in presets, each a complete look:
Applying a preset sets colours, typefaces, corner rounding and light/dark together. Change anything
afterwards and the preset marks itself custom — nothing is locked.
Your presets
Below the built-in row, Save current… writes your design to a.cetheme file in your Themes
folder, where it shows up as a preset you can apply to any course.
Right-click one of your presets for Export / share… (a portable file to send a colleague) or
Delete preset. Import… brings someone else’s in. A background image travels inside the
file, so a shared preset is genuinely self-contained.
Colours
Four swatches, each opening a colour picker:Logo
Choose an image (PNG, JPEG, WebP or SVG) and it replaces the course title in the learner’s top bar. The sidebar keeps the title as text, because that is the navigation’s identity. Clear removes it and the title comes back.Background image
An image shown behind the course pages, dimmed. PNG, JPEG or WebP. Like the logo, it is embedded in the course rather than referenced, so it exports and shares with everything else.Typography
Three pickers — Headings, Body and Code — each choosing from a curated library of eight open-licensed typefaces:
Every chosen typeface is embedded into the exported course, so a published course never depends
on the learner having a font installed. That is why the library is curated: each face is licensed
for redistribution, which a font picked from your own system would not necessarily be.
Earlier versions offered a system-font browser and custom font upload. Both were removed — a
system font meant learners silently got a fallback, and an uploaded font file shipped inside
courses with nothing checking it was licensed to. Courses authored with either still open, and
their font choices are mapped onto the library automatically.
Shape
Corner rounding — 0 to 16 px, applied to cards and blocks in the published course. 0 is squared-off and severe; 12 is the default. Content width — the measure lessons are laid out at:
Individual blocks can override this with their own Block width setting — useful for a wide
diagram in an otherwise narrow course. See Blocks.
Block groups — whether grouped blocks get a visible border drawn around them, or merge
seamlessly.
Mode
Light or Dark, for the published course and its preview. Independent of the editor’s own theme.Reusing a design across courses
Two routes, and the difference matters:A design preset (.cetheme)
Just the look. Apply it to an existing course at any time from the Design tab.
A course template (.cetemplate)
The look plus blocks pinned to the top of the first lesson — a welcome banner, a standard
objectives block. Used when starting a new course.