CTRL + D: toggle display mode
CTRL + P: print or export as PDF
CTRL + S: save source code as .MD file

CTRL + SHIFT + O: open .MD file
CTRL + SHIFT + L: enable / disable LaTeX
CTRL + SHIFT + D: toggle dark mode
CTRL + SHIFT + R: toggle roman or sans-serif font
CTRL + SHIFT + H: show this help dialog

F11: full-screen (in most browsers)