When dealing with more advanced UI elements there are a lot of things that go wrong. They impact performance, accessibility and have the tendency to create frustrations along the way. In this talk, I will be introducing you to the W3C community around Open UI, while also taking a little detour with the Anchoring API. By combining these future specs we'll take a peek at the future of styling custom UI by only using HTML and CSS, giving you less frustration, performance boosts and basic accessibility out of the box.