Followed my curiosity today and explored the limits of what's possible with out Javascript, just pure CSS (with of cos some HTML). And realised, A LOT! Not just fancy animated illustrations but functional UI stuff like sliders, tabs, accordions, toggle buttons, dropdown menus, hamburger menu, input selection, even filters! ...stuff that I always thought needed Javascript! Serendipitously I might have found a solution for a no-JS slider for Collected them all here https://codepen.io/collection/XzkLKL