Themes, fonts, and hide nodes

Pick a theme from the editor (for example Neutral, Forest, Dark, Default, or Base). Themes apply across arrangeable types and preview. Advanced users can also set Mermaid init directives in source when needed.

Change diagram fonts from the toolbar so labels match your deck or design system. Font choice travels with exports and share pages.

Hide nodes to focus a story without deleting them from Mermaid source. Reveal them again when you need the full diagram — useful before Present or a Figma paste.