Mario Hernandez presented on CSS frameworks and progressive enhancements with CSS3. The presentation covered choosing the right CSS framework based on factors like project requirements, fluid grid systems, responsiveness, documentation, and maintenance. Frameworks like Foundation and 960 Grid System were showcased. Grid systems use rows and columns to layout content. Progressive enhancements with CSS3 focus on widely supported properties to enhance the user experience without sacrificing functionality. Additional resources on grids, CSS3, and responsive design were provided.