Always Sunny 03: Header Styling, Image Slant Effect, and Accent Heading Pseudo Text

* Making the header an overlay header
* Positioning the logo like the Figma
* Styling the menu links like the Figma
* A sweet auto-fix using var(–header-height) for hero sections to restore the space that the overlay header takes up and prevent content collisions
* Styling that slanted image with the lower left border effect using a clip path and pseudo element
* Creating that floating heading accent text using data attributes and a mixin.