chore: migrate to Tailwind CSS v4.0 (#632)

* chore: migrate PostCSS configuration to v4

* chore: update dependencies in package.json and package-lock.json

- Bump versions for autoprefixer, postcss, postcss-cli, prettier, and tailwindcss.
- Remove unused dependencies to streamline the project.

* chore: add @tailwindcss/postcss and update package-lock.json

* fix: update import paths in CSS files for consistency

* fix: change prefix from `hx-` to `hx:`

* chore: migrate primary color theme variables to CSS

* fix: remove unnecessary text decoration property from anchor styles in typography CSS

* fix: update CSS styles for improved consistency and clarity across components

* chore: clean up package.json and package-lock.json, remove unused dependencies, and update CSS imports for better organization

* fix: bulk replace prefix `hx-` with `hx:`

* fix: update tailwind css prefix

* fix: styling consistent issues

- steps counter fix in v4
- removed tailwind.css
- update hr border colors
- fix button cursor in v4
- fix border colors in various places

* fix: update class prefixes for consistency in menu and sidebar components

* fix: refine CSS classes and transitions for navbar and sidebar components

- Updated hamburger menu styles for improved animation and structure.
- Adjusted sidebar transition duration for smoother effects.
- Standardized class prefixes for consistency across components.

* fix: update border color in hero badge component for improved styling consistency

* fix: update tab button cursor style for improved user interaction

* chore: recompile css

* fix: dark mode color not applied for before / after elements

* fix: docs navigation

* chore: recompile CSS

* chore: update Tailwind CSS and PostCSS dependencies to version 4.0.17, recompile CSS, and add safelist

* fix: typo in class name and add back decoration-from-font for typography a tags

* fix: update class syntax for Tailwind CSS compatibility in mermaid code block

layouts/shortcodes/hextra/hero-button.html

@@ -7,7 +7,7 @@
 
 <a
   href="{{ $href }}"
-  class="not-prose hx-font-medium hx-cursor-pointer hx-px-6 hx-py-3 hx-rounded-full hx-text-center hx-text-white hx-inline-block hx-bg-primary-600 hover:hx-bg-primary-700 focus:hx-outline-none focus:hx-ring-4 focus:hx-ring-primary-300 dark:hx-bg-primary-600 dark:hover:hx-bg-primary-700 dark:focus:hx-ring-primary-800 hx-transition-all hx-ease-in hx-duration-200"
+  class="not-prose hx:font-medium hx:cursor-pointer hx:px-6 hx:py-3 hx:rounded-full hx:text-center hx:text-white hx:inline-block hx:bg-primary-600 hx:hover:bg-primary-700 hx:focus:outline-hidden hx:focus:ring-4 hx:focus:ring-primary-300 hx:dark:bg-primary-600 hx:dark:hover:bg-primary-700 hx:dark:focus:ring-primary-800 hx:transition-all hx:ease-in hx:duration-200"
   {{ with $style }}style="{{ . | safeCSS }}"{{ end }}
   {{ if $external }}target="_blank" rel="noreferrer"{{ end -}}
 >