Dark mode
Structurizr supports dark mode, determined automatically from your web browser settings, although this can be overridden via the “ Light | Dark | System” links you can find at the bottom of the left navigation pane on the diagrams, documentation, and decisions pages.
PNG/SVG/HTML diagram exports will reflect dark mode too, and please note that dark mode will not change any element or relationship styles on your diagrams, so you may need to modify these so that your diagrams render correctly in both light and dark modes.