Beta 3 of Margen adds LaTeX support, dark mode and multi-language.

LaTeX is the big one. KaTeX loads from CDN the first time you need it,
then renders $…$ as inline math and $$…$$ as block math. So you can
write $E=mc^2$ inline or a full integral in a block. If a formula has
an error it just shows the raw text instead of breaking the preview.

The formula toolbar was important to me because I don’t know LaTeX
syntax by heart. A “formulas” button in the editor header opens a bar
with 16 buttons: square root, integral, fraction, superscript,
subscript, sum, limit, Greek letters, infinity, plus-minus, inequalities,
arrows. Click one and it inserts the LaTeX at the cursor position, then
you just fill in the blanks. No need to remember that integral is
\int_{}^{} or that fraction is \frac{}{}.

Dark mode uses a warm dark palette instead of the usual cold gray, so
it still feels like the typewriter aesthetic. The toggle is in a settings
panel in the sidebar, along with an ES/EN language switch that
translates the whole UI.

Next version will be the last: code syntax highlighting, PDF export,
and PWA installable for offline use on desktop and Android.

But I’m starting to get tired, so i wil be on vacation for the next week!