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2025/4/10 -The :valid CSS pseudo-class represents any <input> or other <form> element whose contents validate successfully.

Note: If you want to validate your CSS style sheet embedded in an (X)HTML document, you should first check that the (X)HTML you use is valid.

The color property in CSS expects a valid color value. Valid color values include keywords (such as red or blue ), hexadecimal values (such as #FFFFFF ) ...

The CSS :valid pseudo-class is used to style valid form elements. Tip: Use the :invalid selector to style invalid form elements.

2010/10/1 -We are required to do a W3C CSS validation of all projects. I actually wrote my css without using the Styles and Formatting pod.

Valid CSS. To fix ... This error typically occurs when there is a syntax issue in the CSS code for the background-color property in your HTML or CSS file.

2015/6/13 -I'm new with coding and I heard from a friend that it's possible to use the :valid and :invalid selectors inside my css for my form. But how do I do this?

This validator checks the markup validity of Web documents in HTML, XHTML, SMIL, MathML, etc. If you wish to validate specific content such as RSS/Atom feeds ...

2025/4/10 -The :user-valid CSS pseudo-class represents any validated form element whose value validates correctly based on its validation constraints.

2024/9/13 -:valid is a pseudo-class selector that enables styling on valid form elements. :valid can be added to any form element, such as <form>, <fieldset>, or <input>.