Feat: Refactor index.njk to be data-driven and fix related rendering issues.
Fix: Resolve layout and functionality bugs, including broken JavaScript for the featured item carousel, layout shifts in category navigation, and CSS issues with the testimonial carousel.
Refactor: Centralize global styles using CSS custom property variables and clean up redundant CSS rules.
This commit refactors the project's directory structure to better align with a static site generator (SSG) workflow. The source files have been moved into a dedicated src directory, and Eleventy has been installed as the new SSG.