https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/::backdrop
::backdrop CSS pseudo-element - CSS | MDN
The ::backdrop CSS pseudo-element is a box the size of the viewport, which is rendered immediately beneath any element being presented in the top layer.
css pseudobackdropelementmdn
https://www.cssportal.com/css-pseudo-class/
CSS Pseudo Classes - CSS Portal
Find examples and definitions for a large range of CSS Pseudo Classes and Pseudo Elements.
css pseudoclassesportal
https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/:where
:where() CSS pseudo-class - CSS | MDN
The :where() CSS pseudo-class function takes a selector list as its argument, and selects any element that can be selected by one of the selectors in that list.
css pseudoclassmdn
https://frontendfoc.us/issues/444
Issue #444: A guide to media queries, and a look at new CSS pseudo-classes on the way. — Frontend...
Frontend Focus Issue #444: A guide to media queries, and a look at new CSS pseudo-classes on the way.
media queriesnew cssissueguidelook
https://bryanlrobinson.com/blog/top-3-uses-of-after-and-before-css-pseudo-elements/
Top 3 uses for the ::before and ::after CSS pseudo elements
It’s no secret that I'm a fan of ::before and ::after pseudo-elements. I use them to great effect for creating darkened overlays in this previous post. They...
css pseudotopuseselements
https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/:dir
:dir() CSS pseudo-class - CSS | MDN
The :dir() CSS pseudo-class matches elements based on the directionality of the text contained in them.
css pseudodirclassmdn
https://frontendfoc.us/issues/488
Issue #488: Here's how to use those new CSS pseudo-class selectors — Frontend Focus
Frontend Focus Issue #488: Here's how to use those new CSS pseudo-class selectors
new csspseudo classissueuseselectors
https://nicolasgallagher.com/an-introduction-to-css-pseudo-element-hacks/
An introduction to CSS pseudo-element hacks – Notes by Nicolas Gallagher
css pseudointroductionelementhacksnotes
https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/:visited
:visited CSS pseudo-class - CSS | MDN
css pseudovisitedclassmdn
https://www.w3.org/TR/css-pseudo-4/
CSS Pseudo-Elements Module Level 4
css pseudomodule levelelements
https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/::selection
::selection CSS pseudo-element - CSS | MDN
The ::selection CSS pseudo-element applies styles to the part of a document that has been highlighted by the user (such as clicking and dragging the mouse...
css pseudoselectionelementmdn
https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/:user-valid
:user-valid CSS pseudo-class - CSS | MDN
The :user-valid CSS pseudo-class represents any validated form element whose value validates correctly based on its validation constraints. However, unlike...
css pseudouservalidclassmdn
https://caniuse.com/css-matches-pseudo
:is() CSS pseudo-class | Can I use... Support tables for HTML5, CSS3, etc
use support tablescss pseudoclassetc
https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/:in-range
:in-range CSS pseudo-class - CSS | MDN
range csspseudo classmdn
https://drafts.csswg.org/css-pseudo-4/
CSS Pseudo-Elements Module Level 4
css pseudomodule levelelements
https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/:read-only
:read-only CSS pseudo-class - CSS | MDN
css pseudoreadclassmdn
https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/:popover-open
:popover-open CSS pseudo-class - CSS | MDN
The :popover-open CSS pseudo-class represents a popover element (i.e., one with a popover attribute) that is in the showing state. You can use this to apply...
css pseudopopoveropenclassmdn
https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/:not
:not() CSS pseudo-class - CSS | MDN
The :not() CSS pseudo-class represents elements that do not match a list of selectors. Since it prevents specific items from being selected, it is known as the...
css pseudoclassmdn
https://blog.frankmtaylor.com/2024/07/18/css-nesting-the-is-pseudo-class-and-a-guide-to-panicking-about-sass/
CSS Nesting, the :is() pseudo-class, and a guide to panicking about Sass – Frank M Taylor
This is a blog post I've been meaning to write for like two years but haven't, because it is a complex topic that's a kind of modern-day Ouroboros where you...
css nestingpseudo classguidepanickingsass
https://css-tricks.com/tag/pseudo-elements/
pseudo elements Archives - CSS-Tricks
elements archivespseudocsstricks
https://www.seanmcp.com/articles/css-empty-pseudo-class/
CSS :empty pseudo class – seanmcp.com
Empty elements in a flex or grid container can result in double gaps, but CSS has an pseudo class to select and remove those elements.
pseudo classcssemptyseanmcp
https://www.trevorlasn.com/blog/css-interest-pseudo-classes
CSS :interest-source and :interest-target Pseudo-Classes
Feb 15, 2026 - Style connected UI elements with CSS pseudo-classes that respond to user interest. Interactive examples showing tooltips, forms, and navigation without JavaS...
cssinterestsourcetargetpseudo
https://modern-css.com/reference/selectors/user-valid/
:user-valid | CSS Selectors & Pseudo-classes
Matches input elements after the user has modified them and they are valid. Provides user-driven validation feedback.
css selectors pseudouservalidclasses
https://modern-css.com/reference/selectors/id/
:id | CSS Selectors & Pseudo-classes
Targets a single, unique element on a page that has a matching 'id' attribute. Since IDs must be unique, this selector should only ever match one element.
css selectors pseudoidclasses
https://modern-css.com/reference/selectors/attribute/
:attribute | CSS Selectors & Pseudo-classes
Allows you to select elements based on the presence or value of their HTML attributes. This is powerful for styling elements like inputs with specific types or...
css selectors pseudoattributeclasses
https://modern-css.com/reference/selectors/view-transition-group/
::view-transition-group | CSS Selectors & Pseudo-classes
Targets the transition 'group' container for a specific named view transition. This is the container that holds both the 'old' and 'new' snapshots of an...
css selectors pseudoview transitiongroupclasses
https://devtoolstips.org/tips/en/simulate-pseudo-classes/
Simulate pseudo CSS classes
Simulate pseudo CSS classes
simulatepseudocssclasses
https://modern-css.com/reference/selectors/target-after/
:target-after | CSS Selectors & Pseudo-classes
An experimental pseudo-class that matches a 'scroll marker' when it represents an item that comes AFTER the current viewport in a scroll container.
css selectors pseudotargetclasses
https://modern-css.com/reference/selectors/host/
:host() | CSS Selectors & Pseudo-classes
Allows you to style the 'host' (the custom element itself) from within the element's own Shadow DOM. It's the standard way to set a component's default...
css selectors pseudohostclasses
https://modern-css.com/reference/selectors/interest-target/
:interest-target | CSS Selectors & Pseudo-classes
Experimental: Targets the 'target' of an interest action (like the tooltip or popover itself) while it is currently being shown.
css selectors pseudointeresttargetclasses
https://modern-css.com/reference/selectors/picker-icon/
::picker-icon | CSS Selectors & Pseudo-classes
css selectors pseudopickericonclasses
https://modern-css.com/reference/selectors/checked/
:checked | CSS Selectors & Pseudo-classes
A pseudo-class that targets checkboxes, radio buttons, or option elements that are currently selected (checked) by the user.
css selectors pseudocheckedclasses
https://modern-css.com/reference/selectors/lang/
:lang | CSS Selectors & Pseudo-classes
Matches elements by language. Use to style different languages differently without adding classes.
css selectors pseudolangclasses
https://caniuse.com/?search=ciu/css-optional-pseudo
"ciu/css-optional-pseudo" | Can I use... Support tables for HTML5, CSS3, etc
use support tablesciu cssoptionalpseudoetc
https://modern-css.com/reference/selectors/valid/
:valid | CSS Selectors & Pseudo-classes
Targets any form element that currently meets its requirements (like matching a 'pattern' or having content in a 'required' field). Unlike ':user-valid', this...
css selectors pseudovalidclasses
https://modern-css.com/reference/selectors/in-range/
:in-range | CSS Selectors & Pseudo-classes
Targets form inputs (like type='number') whose current value is between the minimum and maximum limits set by 'min' and 'max' attributes.
css selectors pseudorangeclasses
https://modern-css.com/text-highlighting-without-dom-manipulation/
CSS Custom Highlight API: ::highlight() Pseudo-Element
Apr 19, 2026 - Highlight arbitrary text ranges with the CSS Custom Highlight API and ::highlight(). No wrapping spans in innerHTML or breaking the DOM with surroundContents().
css customhighlightapipseudoelement
https://modern-css.com/reference/selectors/invalid/
:invalid | CSS Selectors & Pseudo-classes
Targets form inputs that contain data that doesn't follow the rules set by attributes like 'required', 'pattern', or 'type'.
css selectors pseudoinvalidclasses
https://modern-css.com/reference/selectors/scroll-marker-group/
::scroll-marker-group | CSS Selectors & Pseudo-classes
A new experimental pseudo-element that acts as a container for individual 'scroll markers'. It's used to create native CSS carousels with built-in navigation...
css selectors pseudoscrollmarkergroupclasses
https://modern-css.com/reference/selectors/defined/
:defined | CSS Selectors & Pseudo-classes
Matches any element that has been officially 'defined' by the browser. This includes all standard HTML elements and any custom elements that have been...
css selectors pseudodefinedclasses
https://modern-css.com/reference/selectors/visited/
:visited | CSS Selectors & Pseudo-classes
Matches any link that the user has already visited in their browser. For privacy reasons, the browser only allows you to change a few specific properties (like...
css selectors pseudovisitedclasses
https://modern-css.com/reference/selectors/nth-last-of-type/
:nth-last-of-type() | CSS Selectors & Pseudo-classes
css selectors pseudonthlasttypeclasses
https://modern-css.com/reference/selectors/default/
:default | CSS Selectors & Pseudo-classes
A pseudo-class that targets form elements (like buttons or checkboxes) that are the default among a set of similar elements.
css selectors pseudodefaultclasses
https://modern-css.com/reference/selectors/first-of-type/
:first-of-type | CSS Selectors & Pseudo-classes
A pseudo-class that targets the first element of its specific type within a parent. For example, 'p:first-of-type' targets the first paragraph, even if it's...
css selectors pseudofirsttypeclasses
https://modern-css.com/reference/selectors/modal/
:modal | CSS Selectors & Pseudo-classes
css selectors pseudomodalclasses
https://modern-css.com/reference/selectors/last-of-type/
:last-of-type | CSS Selectors & Pseudo-classes
css selectors pseudolasttypeclasses
https://modern-css.com/reference/selectors/muted/
:muted | CSS Selectors & Pseudo-classes
css selectors pseudomutedclasses
https://modern-css.com/reference/selectors/user-invalid/
:user-invalid | CSS Selectors & Pseudo-classes
Matches input elements after the user has modified them and they are invalid. Shows validation errors to users.
css selectors pseudouserinvalidclasses
https://modern-css.com/reference/selectors/dir/
:dir | CSS Selectors & Pseudo-classes
Matches elements based on text direction (ltr or rtl). Useful for bi-directional text layouts.
css selectors pseudodirclasses
https://modern-css.com/reference/selectors/view-transition-new/
::view-transition-new | CSS Selectors & Pseudo-classes
Targets the 'new' state's snapshot in a view transition. This is the image of how the element looks AFTER the change, allowing you to specifically animate how...
css selectors pseudoview transitionnewclasses
https://modern-css.com/reference/selectors/has-slotted/
:has-slotted | CSS Selectors & Pseudo-classes
Matches a 'slot' in the Shadow DOM if it contains content that matches the selector. It's used within Web Components to style slots based on what's been put...
css selectors pseudoslottedclasses
https://modern-css.com/reference/selectors/interest-source/
:interest-source | CSS Selectors & Pseudo-classes
Experimental: Targets an element that is currently the 'source' of interest (the element being hovered or focused) which is triggering an interest-based UI...
css selectors pseudointerestsourceclasses
https://modern-css.com/reference/selectors/is/
:is | CSS Selectors & Pseudo-classes
Matches any selector in its argument list. Useful for grouping related selectors.
css selectors pseudoclasses
https://modern-css.com/reference/selectors/popover-open/
:popover-open | CSS Selectors & Pseudo-classes
Matches elements with the popover attribute that are currently in their open state. It allows you to style top-layer content like menus and tooltips...
css selectors pseudopopoveropenclasses
https://modern-css.com/reference/selectors/highlight/
::highlight | CSS Selectors & Pseudo-classes
Targets custom text highlights created via the CSS Highlight API. It allows you to style specific ranges of text programmatically (ideal for...
css selectors pseudohighlightclasses
https://modern-css.com/reference/selectors/enabled/
:enabled | CSS Selectors & Pseudo-classes
A pseudo-class that targets form elements (like inputs or buttons) that are in an 'enabled' state and can be interacted with.
css selectors pseudoenabledclasses
https://caniuse.com/?search=ciu/css-indeterminate-pseudo
"ciu/css-indeterminate-pseudo" | Can I use... Support tables for HTML5, CSS3, etc
use support tablesciu cssindeterminatepseudoetc
https://modern-css.com/reference/selectors/fullscreen/
:fullscreen | CSS Selectors & Pseudo-classes
Targets an element while it is being displayed in the browser's full-screen mode (e.g., when a video or a photo is expanded to fill the whole monitor).
css selectors pseudofullscreenclasses
https://modern-css.com/reference/selectors/scroll-marker/
::scroll-marker | CSS Selectors & Pseudo-classes
A new experimental pseudo-element that represents an individual navigation dot in a carousel. You can style these dots (like an active/inactive state) directly...
css selectors pseudoscrollmarkerclasses
https://modern-css.com/reference/selectors/placeholder-shown/
:placeholder-shown | CSS Selectors & Pseudo-classes
css selectors pseudoplaceholdershownclasses
https://modern-css.com/reference/selectors/next-sibling/
:next-sibling | CSS Selectors & Pseudo-classes
Targets an element that is immediately following another element at the same level in the HTML structure.
css selectors pseudonextsiblingclasses
https://caniuse.com/?search=ciu/css-marker-pseudo
"ciu/css-marker-pseudo" | Can I use... Support tables for HTML5, CSS3, etc
use support tablesciu cssmarkerpseudoetc
https://modern-css.com/reference/selectors/subsequent-sibling/
:subsequent-sibling | CSS Selectors & Pseudo-classes
Matched by the '~' symbol, this selector targets any siblings that come AFTER the specified element in the HTML. It doesn't have to be the very next sibling.
css selectors pseudosubsequentsiblingclasses
https://modern-css.com/reference/selectors/nth-last-child/
:nth-last-child() | CSS Selectors & Pseudo-classes
Works exactly like :nth-child(), but it counts backwards from the very last element in the container.
css selectors pseudolast childnthclasses
https://modern-css.com/reference/selectors/spelling-error/
::spelling-error | CSS Selectors & Pseudo-classes
A pseudo-element that allows you to customize the styling of words that the browser identifies as having spelling errors.
css selectors pseudospellingerrorclasses
https://modern-css.com/reference/selectors/before/
::before | CSS Selectors & Pseudo-classes
Creates a 'virtual' element that appears as the first child of the selected element. It's often used for quotes, bullet icons, or other decorative elements...
css selectors pseudoclasses
https://modern-css.com/reference/selectors/backdrop/
::backdrop | CSS Selectors & Pseudo-classes
Styles the area behind a full-screen element or dialog. It allows you to dim the background or add effects like blur when a modal is active.
css selectors pseudobackdropclasses
https://modern-css.com/reference/selectors/first-letter/
::first-letter | CSS Selectors & Pseudo-classes
A pseudo-element that targets the very first letter of the first line of a block-level element. perfect for creating drop caps.
css selectors pseudofirstletterclasses
https://modern-css.com/reference/selectors/view-transition-image-pair/
::view-transition-image-pair | CSS Selectors & Pseudo-classes
Targets the 'pair' of images (the old snapshot and the new snapshot) within a view transition group. This is where the cross-fade between the two states...
css selectors pseudoview transitionimagepairclasses
https://modern-css.com/reference/selectors/right/
:right | CSS Selectors & Pseudo-classes
A selector used in paged media (like printing) to style only the right-hand pages of a document (usually odd-numbered pages).
css selectors pseudorightclasses
https://modern-css.com/reference/selectors/xr-overlay/
xr-overlay | CSS Selectors & Pseudo-classes
An experimental pseudo-class that targets the root element of a 'DOM Overlay' when a web page is being viewed in an Immersive AR or VR environment.
css selectors pseudoxroverlayclasses
https://modern-css.com/reference/selectors/target-text/
::target-text | CSS Selectors & Pseudo-classes
A pseudo-element that allows you to style text that has been targeted via a URL fragment (the part after the # in a URL). This is often used for...
css selectors pseudotargettextclasses
https://modern-css.com/reference/selectors/nth-of-type/
:nth-of-type() | CSS Selectors & Pseudo-classes
Targets elements based on their position among siblings of the same type. For example, it can target 'the second image' even if there are paragraphs in between.
css selectors pseudonthtypeclasses
https://modern-css.com/reference/selectors/only-of-type/
:only-of-type | CSS Selectors & Pseudo-classes
Targets an element that is the ONLY child of its type among its siblings. For example, 'the only image' in a div, even if there's also text.
css selectors pseudotypeclasses
https://modern-css.com/reference/selectors/universal/
:universal | CSS Selectors & Pseudo-classes
The 'asterisk' selector that matches every single element on the page. It is commonly used in CSS resets to apply a base style (like 'box-sizing: border-box')...
css selectors pseudouniversalclasses
https://modern-css.com/reference/selectors/link/
:link | CSS Selectors & Pseudo-classes
css selectors pseudoclasses
https://modern-css.com/reference/selectors/only-child/
:only-child | CSS Selectors & Pseudo-classes
Targets an element that is the ONLY child of its parent. If there are any other elements (even of a different type), it won't match.
css selectors pseudochildclasses
https://modern-css.com/reference/selectors/view-transition-old/
::view-transition-old | CSS Selectors & Pseudo-classes
Targets the 'old' state's snapshot in a view transition. This is the image of how the element looked BEFORE the change, allowing you to animate how it fades...
css selectors pseudoview transitionoldclasses
https://modern-css.com/reference/selectors/hostfunction/
:hostfunction | CSS Selectors & Pseudo-classes
Used inside a Shadow DOM to style the 'host' element (the custom element itself). The functional version ':host()' lets you apply styles only if the host...
css selectors pseudoclasses
https://modern-css.com/reference/selectors/last-child/
:last-child | CSS Selectors & Pseudo-classes
Targets an element only if it is the very last child inside its parent container.
css selectors pseudolast childclasses
https://modern-css.com/reference/selectors/empty/
:empty | CSS Selectors & Pseudo-classes
A pseudo-class that targets any element that has absolutely no content inside it (not even whitespace or children).
css selectors pseudoemptyclasses
https://modern-css.com/reference/selectors/root/
:root | CSS Selectors & Pseudo-classes
css selectors pseudorootclasses
https://modern-css.com/reference/selectors/picker/
::picker | CSS Selectors & Pseudo-classes
css selectors pseudopickerclasses
https://caniuse.com/?search=ciu/css-default-pseudo
"ciu/css-default-pseudo" | Can I use... Support tables for HTML5, CSS3, etc
use support tablesciu cssdefaultpseudoetc
https://modern-css.com/reference/selectors/host-context/
:host-context() | CSS Selectors & Pseudo-classes
A pseudo-class used in Web Components to style the custom element based on its position in the outside page (e.g., styling a component differently if it's...
css selectors pseudohostcontextclasses
https://modern-css.com/reference/selectors/disabled/
:disabled | CSS Selectors & Pseudo-classes
A pseudo-class that targets elements that are in a disabled state (like a button with the 'disabled' attribute), making them unclickable and often grayed out.
css selectors pseudodisabledclasses
https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/Pseudo-classes
Pseudo-classes - CSS | MDN
A CSS pseudo-class is a keyword added to a selector that lets you select elements based on information that lies outside of the document tree, such as a...
pseudoclassescssmdn
https://modern-css.com/reference/selectors/descendant/
:descendant | CSS Selectors & Pseudo-classes
The most common CSS combinator (a simple space). It targets an element that is inside (a descendant of) another specified element, no matter how deeply nested.
css selectors pseudodescendantclasses
https://modern-css.com/reference/selectors/loop/
:loop | CSS Selectors & Pseudo-classes
css selectors pseudoloopclasses