Migrate to Tailwind CSS

[hdcodedev]

Summary

We should migrate charts-docs to use Tailwind CSS for styling.

Benefits

• Faster development with utility-first CSS
• Easier to maintain and update styles
• Consistent styling across the application
• Better developer experience with autocomplete

Requirements

1. Install tailwindcss and its dependencies
2. Configure Tailwind for the Next.js project
3. Migrate existing styles to Tailwind classes

[hdcodedev]

Closed — addressed or superseded by modernization work in #44.