The :default CSS pseudo-class selects form elements that are the default in a group of related elements.

<fieldset>   <legend>Favorite season</legend>    <input type="radio" name="season" id="spring">   <label for="spring">Spring</label>    <input type="radio" name="season" id="summer" checked>   <label for="summer">Summer</label>    <input type="radio" name="season" id="fall">   <label for="fall">Fall</label>    <input type="radio" name="season" id="winter">   <label for="winter">Winter</label> </fieldset> 

:default

The :default CSS pseudo-class selects form elements that are the default in a group of related elements.

What this selector matches is defined in HTML Standard §4.16.3 Pseudo-classes — it may match the <button>, <input type="checkbox">, <input type="radio">, and <option> elements:

A default option element is the first one with the selected attribute, or the first enabled option in DOM order. multiple <select>s can have more than one selected option, so all will match :default. <input type="checkbox"> and <input type="radio"> match if they have the checked attribute. <button> matches if it is a <form>'s default submission button: the first <button> in DOM order that belongs to the form. This also applies to <input> types that submit forms, like image or submit.

Syntax

:default

Examples

HTML

<fieldset>   <legend>Favorite season</legend>    <input type="radio" name="season" id="spring">   <label for="spring">Spring</label>    <input type="radio" name="season" id="summer" checked>   <label for="summer">Summer</label>    <input type="radio" name="season" id="fall">   <label for="fall">Fall</label>    <input type="radio" name="season" id="winter">   <label for="winter">Winter</label> </fieldset> 

CSS

input:default {   box-shadow: 0 0 2px 1px coral; }  input:default + label {   color: coral; } 

Result

Specifications

Specification
HTML Standard # selector-default
Selectors Level 4 # default-pseudo

See also

Web forms — Working with user data Styling web forms Related HTML elements: <button>, <input type="checkbox">, <input type="radio">, and <option> Select your preferred language English (US)DeutschEspañolFrançais日本語한국어Русский中文 (简体) Change language