Email-Blueprints : Email Blueprints is a collection of HTML email templates that can serve as a solid foundation and starting point for the design of emails.
darken : Easy control over your dark mode in a web environment
YAML Builder : A tool for visual layout development of YAML based CSS layouts
This Is Responsive : Tips, Resources and Patterns for Responsive Web Design
The CSS Text Wrapper allows you to easily make HTML text wrap in shapes other than just a rectangle. You can make text wrap around curves, zig-zags, or whatever you want.