Bookmark landing page solution using HTML5 && CSS3 && Js

In this solution I have put into practice some topics that I have been learning recently, first I tried to Create a Design system and put all design tokens in it, and secondary was the accessibility, I have tried to make the website accessible via keyboard, but the most confusing part was the tab, I follow this article from MDN, but I get too many errors, so I decide to use my one custom data-attribute,

Please if you have any suggestions or recommendations or criticism. you are more than welcome, I will love to hear you thoughts. Have a Good Week!!