by iamaliiraja on WordPress.org

Custom CSS panel in action in the Gutenberg editor (GIF)
Super Block CSS allows you to add custom CSS to your Blocks straight from the Block Editor (Gutenberg). It adds a syntax-highlighted CSS Editor where you can add additional CSS to your Gutenberg Blocks to style them the way you want.
Key features:
Whether you’re a developer looking to fine-tune your blocks or a site owner wanting to add some custom flair, Super Block CSS gives you the power to customize your Gutenberg blocks with ease.