Selector for list items that are not hidden

Explanation

This is a CSS selector that selects all li elements that are directly nested within a ul element and that do not have a data-hidden attribute. The > symbol indicates that the li elements must be direct children of the ul element. The :not([data-hidden]) part of the selector is a negation pseudo-class, which selects elements that do not have the specified attribute. In this case, it selects all li elements that do not have a data-hidden attribute.