Write custom CSS using your editor of choice.
Before synchronizing an external CSS file, make sure to save your current theme's CSS if haven't done so already.
- Go to
File -> Preferences -> CSS Companion...
- Click on the grey input box "Watch file", it will prompt you to select a file
- Tick
Watching
- You're done! Changes you make to the synced file will apply to Blockbench in real-time (every time the file is saved)
If you leave Watching
enabled and close Blockbench, CSS synchronization will continue next time.