Custom Styling Gutenberg Blocks

Its a bit tricky to style with Gutenberg blocks. It often does not work just by adding custom styles through styles.css in a child theme. The following two resources are very useful for customizing Gutenberg blocks.

The WordPress theme team member Carolina Nymark has created a WordPress Block Styles sited with tutorials & guides to style blocks. This site has very useful guides, tutorials designed for beginners.

The WordPress Gutenberg team has a GitHub discussion note titled A Block Style System customizing common attributes of blocks (typography, colors, etc).