Why Does `input:not(:empty)` Always Return No Results?

Understanding the :not(:empty) CSS Selector

The :empty CSS selector is designed to match elements that contain no child elements. However, when used in combination with the :not() selector, it can lead to unexpected behavior.

The Case of Input Elements

The HTML element is considered a "void element," meaning it doesn't have any children. Therefore, it will always satisfy the :empty selector, regardless of whether it contains any text value or not.

When using input:not(:empty), you're essentially asking for elements that are both empty and not empty. This is a contradiction, which is why the selector never returns any results.

Implications for CSS Styling

This behavior has implications for CSS styling. You cannot use input:not(:empty) to dynamically style input fields based on whether they're empty or not.

Alternative Solutions

To style initially empty input fields, you can use selectors like input[value=""] or input:not([value]). However, once a user enters text into the field, it will no longer match these selectors.

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