What’s next for CSS?

all Property

A property for defining the reset of all properties of an element

a {
  all: initial;
}

font-variant Property

A property for defining the usage of alternate glyphs in a font

h2 {
  font-variant: small-caps;
}

Break Properties

Properties for defining the break behavior between and within boxes

a {
  break-inside: avoid;
  break-before: avoid-column;
  break-after: always;
}

Custom Properties

A syntax for defining custom values accepted by all CSS properties

:root {
  --some-length: 32px;

  height: var(--some-length);
  width: var(--some-length);
}

Gap Properties

Properties for defining gutters within a layout

.grid-1 {
  gap: 20px;
}

.grid-2 {
  column-gap: 40px;
  row-gap: 20px;
}

Grid Layout

A syntax for using a grid concept to lay out content

section {
  display: grid;
  grid-template-columns: 100px 100px 100px;
  grid-gap: 10px;
}

Media Query Ranges

A syntax for defining media query ranges using ordinary comparison operators

@media (width < 480px) {}

@media (480px <= width < 768px) {}

@media (width >= 768px) {}

unset Keyword

The unset CSS keyword resets a property to its inherited value if the property naturally inherits from its parent, and to its initial value if not.

div {
  border-color: unset;
  color: unset;
}

alpha() Function

Relative alpha colors

p {
  color: alpha(from red / calc(alpha * 0.5));
}

:any-link Hyperlink Pseudo-Class

A pseudo-class for matching anchor elements independent of whether they have been visited

nav :any-link > span {
  background-color: yellow;
}

:blank Empty-Value Pseudo-Class

A pseudo-class for matching form elements when they are empty

input:blank {
  background-color: yellow;
}

e, pi, infinity, -infinity and NaN constants for calculation

Constants for calculation simplification

p {
  font-size: calc(pow(e, pi) * 1rem);
}

CSS Cascade Layers

The @layer at-rule allows authors to explicitly layer their styles in the cascade, before specificity and order of appearance are considered.

/* Un-layered styles have the highest priority */
a {
  color: mediumvioletred;
}

@layer defaults {
  a { color: maroon; }
}

Case-Insensitive Attributes

An attribute selector matching attribute values case-insensitively

[frame=hsides i] {
  border-style: solid none;
}

clamp Function

The clamp() CSS function clamps a value between an upper and lower bound. It enables selecting a middle value within a range of values between a defined minimum and maximum.

button {
  font-size: clamp(1rem, 2.5vw, 2rem);
}

color-adjust Property

The color-adjust property is a non-standard CSS extension that can be used to force printing of background colors and images

.background {
  background-color:#ccc;
}
.background.color-adjust {
  color-adjust: economy;
}
.background.color-adjust-exact {
  color-adjust: exact;
}

color() Function

A function that allows a color to be specified in a particular, specified color space rather than the implicit sRGB color space that most of the other color functions operate in.

p {
  color: color(display-p3 1 0.5 0);
  color: color(display-p3 1 0.5 0 / .5);
}

The display-p3-linear Color Space for the color() Function

The display-p3-linear predefined color space is the same as display-p3 except that the transfer function is linear-light.

p {
  color: color(display-p3-linear 0.3081 0.014 0.0567);
}

Color Functional Notation

A space and slash separated notation for specifying colors

em {
  background-color: hsl(120deg 100% 25%);
  color: rgb(0 255 0);
}

color-mix() Function

A function for mixing colors

p {
  color: color-mix(in lch, purple 50%, plum 50%);
}

color-mix() Function with 1+ arguments

Mix any number of colors

p {
  color: color-mix(in lch, red, lime, blue);
}

Container Queries

New container property and container at rule to make changes depending on the container's size

.container {
  contain: layout inline-size;
}

@container (min-width: 700px) {
  .container {
    /* styles applied when a container is at least 700px */
  }
}

Alt text for content

Syntax that allows setting alternative text

.element {
  content: url(tree.jpg) / "image with a tree";
}

contrast-color() Function

Dynamically specifying a text color with adequate contrast.

p {
  color: contrast-color( purple );
}

Custom Media Queries

An at-rule for defining aliases that represent media queries

@custom-media --narrow-window (max-width: 30em);

@media (--narrow-window) {}

:dir Directionality Pseudo-Class

A pseudo-class for matching elements based on their directionality

blockquote:dir(rtl) {
  margin-right: 10px;
}

blockquote:dir(ltr) {
  margin-left: 10px;
}

Two values syntax for display

Syntax that allows definition of outer and inner displays types for an element

.element {
  display: inline flow-root;
  display: inline flex;
  display: block grid;
}

Double Position Gradients

A syntax for using two positions in a gradient.

.pie_chart {
  background-image: conic-gradient(yellowgreen 40%, gold 0deg 75%, #f06 0deg);
}

pow(), sqrt(), hypot(), log(), exp() exponential functions

Compute various exponential functions with their arguments

p {
  font-size: calc(pow(10, 12) * 1rem);
  font-size: calc(sqrt(100) * 1rem);
  font-size: calc(hypot(3, 4) * 1rem);
  font-size: calc(log(10) * 1rem);
  font-size: calc(exp(10) * 1rem);
}

fangsong Font Family

A generic font used for Fang Song (仿宋) typefaces in Chinese

body {
  font-family: fangsong;
}

Logical Values in float and clear

Flow-relative (inline-start and inline-end) values for float and clear

span:first-child {
  float: inline-start;
}

:focus-visible Focus-Indicated Pseudo-Class

A pseudo-class for matching focused elements that indicate that focus to a user

:focus:not(:focus-visible) {
  outline: 0;
}

:focus-within Focus Container Pseudo-Class

A pseudo-class for matching elements that are either focused or that have focused descendants

form:focus-within {
  background: rgb(0 128 0);
}

Font format() Keywords

A syntax for specifying font format as a keyword in @font-face rule’s format() function

@font-face {
  src: url(file.woff2) format(woff2);
}

Gamut mapping for CSS color functions

Gamut map css colors to fit display specific gamuts.

@media (color-gamut: rec2020) {
	p {
		color: oklch(40% 0.234 0.39 / 0.5);
	}
}

Gradients Interpolation Method

Define the interpolation method for gradients

.pie_chart {
  background-image: conic-gradient(in oklch, yellowgreen 40%, gold 0deg 75%, #f06 0deg);
}

:has() Relational Pseudo-Class

A pseudo-class for matching ancestor and sibling elements

a:has(> img) {
  display: block;
}

Hexadecimal Alpha Notation

A 4 & 8 character hex color notation for specifying the opacity level

section {
  background-color: #f3f3f3f3;
  color: #0003;
}

hwb() Function

A function for specifying colors by hue and then a degree of whiteness and blackness to mix into it

p {
  color: hwb(120 44% 50%);
}

ic length unit

Equal to the used advance measure of the "水" (CJK water ideograph, U+6C34) glyph found in the font used to render it

p {
  text-indent: 2ic;
}

image-set() Function

A function for specifying image sources based on the user’s resolution

p {
  background-image: image-set(
    "foo.png" 1x,
    "foo-2x.png" 2x,
    "foo-print.png" 600dpi
  );
}

:in-range and :out-of-range Pseudo-Classes

A pseudo-class for matching elements that have range limitations

input:in-range {
  background-color: rgb(0 255 0 / 0.25);
}
input:out-of-range {
  background-color: rgb(255 0 0 / 0.25);
  border: 2px solid red;
}

:is() Matches-Any Pseudo-Class

A pseudo-class for matching elements in a selector list

p:is(:first-child, .special) {
  margin-top: 1em;
}

lab() Function

A function for specifying colors expressed in the CIE Lab color space

body {
  color: lab(80% 50 20);
}

lch() Function

A function for specifying colors expressed in the CIE Lab color space with chroma and hue

body {
  color: lch(53% 105 40);
}

light-dark() Function

React to the current used color-scheme value

body {
  color: light-dark(cyan, magenta);
}

Logical Overflow

Flow-relative overflow properties

div {
  overflow-block: scroll;
}

Logical Overscroll Behavior

Flow-relative overscroll-behavior properties

div {
  overscroll-behavior-block: scroll;
}

Logical Properties and Values

Flow-relative (left-to-right or right-to-left) properties and values

span:first-child {
  margin-inline-start: 10px;
}

Logical values in the resize property

Flow-relative (block or inline) values in resize

area {
  resize: inline;
}

Logical Viewport Units

Flow-relative (horizontal or vertical) Viewport Units

span:first-child {
  width: 5vi; height: 10vb; 
}

Aspect-Ratio number values

Support <ratio> values with <number> components in @media

@media (aspect-ratio: 1.77) {
  html {
    background-color: cyan;
  }
}

Nested calc()

Nest calc functions with the calc function name

p {
  padding: calc(1px + calc(4 / 3));
}

Nesting Rules

A syntax for nesting relative rules within rules

article {
  & p {
    color: #333;
  }
}

:not() Negation List Pseudo-Class

A pseudo-class for ignoring elements in a selector list

p:not(:first-child, .special) {
  margin-top: 1em;
}

oklab and oklch color functions

Functions that allow colors to be expressed in OKLab and OKLCH.

p {
  color: oklab(72.322% -0.0465 -0.1150);
  color: oklch(72.322% 0.12403 247.996);
}

Support for percentages for opacity

Syntactic sugar to use percentages instead of a float between 0 and 1.

img {
  opacity: 90%;
}

overflow Shorthand Property

A property for defining overflow-x and overflow-y

html {
  overflow: hidden auto;
}

overflow-wrap Property

A property for defining whether to insert line breaks within words to prevent overflowing

p {
  overflow-wrap: break-word;
}

overscroll-behavior Property

Properties for controlling when the scroll position of a scroll container reaches the edge of a scrollport

.messages {
  height: 220px;
  overflow: auto;
  overscroll-behavior-y: contain;
}

body {
  margin: 0;
  overscroll-behavior: none;
}

Place Properties

Properties for defining alignment within a layout

.example {
  place-content: flex-end;
  place-items: center / space-between;
  place-self: flex-start / center;
}

prefers-color-scheme Media Query

A media query to detect if the user has requested the system use a light or dark color theme

body {
  background-color: white;
  color: black;
}

@media (prefers-color-scheme: dark) {
  body {
    background-color: black;
    color: white;
  }
}

prefers-reduced-motion Media Query

A media query to detect if the user has requested less animation and general motion on the page

.animation {
  animation: vibrate 0.3s linear infinite both; 
}

@media (prefers-reduced-motion: reduce) {
  .animation {
    animation: none;
  }
}

random() function

Represents a random value between a minimum and maximum value, drawn from a uniform distribution, optionally limiting the possible values to a step between those limits

div {
  color: oklch(0.7, 0.2, random(120deg, 240deg));
}

:read-only and :read-write selectors

Pseudo-classes to match elements which are considered user-alterable

input:read-only {
  background-color: #ccc;
}

rebeccapurple Color

A particularly lovely shade of purple in memory of Rebecca Alison Meyer

html {
  color: rebeccapurple;
}

Relative Colors

Modify existing colors using color functions

p {
  color: lch(from peru calc(l * 0.8) c h);
}

:scope() Reference Element Pseudo-class

A pseudo-class for matching one or more scoping roots

:scope {
  background-color: pink;
}

abs() and sign() functions

The sign-related functions—abs() and sign()—compute various functions related to the sign of their argument

div {
  order: abs(-10);
  order: sign(-10);
}

src() function

The argument of src() can be provided by functions, such as var(). Otherwise this behaves the same as url()

div {
  background: src('./image.jpg');
}

round(), mod() and rem() functions

The stepped-value functions, round(), mod(), and rem(), all transform a given value according to another "step value", in different ways

div {
  left: mod(18px, 5px);
  top: rem(18px, 5px);
  right: round(2.5px, 1px);
  bottom: round(up, 15px, 7px);
}

system-ui Font Family

A generic font used to match the user’s interface

body {
  font-family: system-ui;
}

text-decoration shorthand

A property for defining text-decoration-line, text-decoration-thickness, text-decoration-style and text-decoration-color

p {
  text-decoration: green wavy underline 2px;
}

sin(), cos(), tan(), asin(), acos(), atan() and atan2() functions

Functions to calculate various basic trigonometric relationships

body {
  left: sin(45deg);
  left: cos(45deg);
  left: tan(45deg);
  left: asin(0.5);
  left: acos(0.5);
  left: atan(10);
  left: atan2(-1, 1);
}

When/Else Rules

At-rules for specifying media queries and support queries in a single grammar

@when media(width >= 640px) and (supports(display: flex) or supports(display: grid)) {
  /* A */
} @else media(pointer: coarse) {
  /* B */
} @else {
  /* C */
}

:where() Zero-Specificity Pseudo-Class

A pseudo-class for matching elements in a selector list without contributing specificity

a:where(:not(:hover)) {
  text-decoration: none;
}

Custom Selectors

An at-rule for defining aliases that represent selectors

@custom-selector :--heading h1, h2, h3, h4, h5, h6;

article :--heading + p {}

Custom Environment Variables

A syntax for using custom values accepted by CSS globally

@media (max-width: env(--brand-small)) {
  body {
    padding: env(--brand-spacing);
  }
}