What UI elements would you like to see used more in web pages?

I am developing my own front-end framework and right now I am thinking about new components to add to the codebase apart from the very common ones.

What UI elements do you think are not used enough in web pages and web applications? What kinds of controls do you think should we use more often and how can they be styled to feel intuitive?

Examples of use and links (especially Codepens) are appreciated.