Selectors - CSS Reference - page 76

Name
:disabled
Applies to:
Any element
Description:
Matches user interface elements that are not able to accept user input because of language at-
tributes or other nonpresentational means; for example, <input type="text" disabled> in
HTML5. Note that :disabled does notapply when an input element has simply been re-
moved from the viewport with properties like position or display .
Examples:
input:disabled {opacity: 0.5;}