Editor?.Css.addRules(targetCss);

This is not a bug, Css.addRules doesn't have any option argument. You can open a discussion in regard to this topic and we can see if it makes sense to introduce it

ok, I get it,I need to add some styles in front of an array, not at the end. such as arr.unshift(css) How can I do that? I might need a little help from you

Thanks for reporting this, @pittleCheung.

Great question about editor?.Css.addRules(targetCss);. The recommended approach with StyleManager is to use the event-driven API.

Start here:

1. Check the GrapesJS documentation for your specific module
2. Look for the on() event listener method
3. Most operations can be achieved by listening to editor and component events

Common patterns:

// Listen for changes
editor.on('change', () => console.log('something changed'));

// Component lifecycle
editor.on('component:mount', (c) => console.log('component ready', c));
editor.on('component:update', (c) => console.log('component updated', c));

If you're still stuck:

• Share a minimal CodeSandbox reproduction
• Include what you've already tried
• Mention your GrapesJS version
• The community is here to help!