Parsen von JavaScript verzögern: https://kinsta.com/de/blog/parsen-von-javascript-verzogert/
WordPress-Suche um Custom Fields erweitern: https://adambalee.com/search-wordpress-by-custom-fields-without-a-plugin/
Custom Select ohne select2: https://www.w3schools.com/howto/howto_custom_select.asp
Radio-Button und Check-Box-Styling: https://doodlenerd.com/html-control/css-radio-button-generator https://doodlenerd.com/html-control/css-checkbox-generator
Scroll Percentage JS: https://codepen.io/achudars/pen/Cpast
Only Menu Links WordPress Nav Walker: https://wordpress.stackexchange.com/questions/33175/get-menu-links-only