:blank
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
Note: The :blank selector is considered at risk, as the CSSWG keeps changing it.
See CSSWG issue #1967.
The :blank CSS pseudo-class selects empty user input elements (e.g. <input> or <textarea>).
Syntax
css
:blank {
  /* ... */
}
Examples
Simple :blank example
In eventual supporting browsers, the :blank pseudo-class will enable developers to highlight in some way input controls that are not required, but still have no content filled in, perhaps as a reminder to users.
HTML
html
<textarea></textarea>
CSS
css
textarea:blank {
  border: 3px solid red;
}
Result
Specifications
| Specification | 
|---|
| Selectors Level 4 # blank-pseudo | 
Browser compatibility
BCD tables only load in the browser