transition - CSS: Cascading Style Sheets 编辑

The transition CSS property is a shorthand property for transition-property, transition-duration, transition-timing-function, and transition-delay.

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Transitions enable you to define the transition between two states of an element. Different states may be defined using pseudo-classes like :hover or :active or dynamically set using JavaScript.

Constituent properties

This property is a shorthand for the following CSS properties:

• transition-delay
• transition-duration
• transition-property
• transition-timing-function

Syntax

/* Apply to 1 property */
/* property name | duration */
transition: margin-right 4s;

/* property name | duration | delay */
transition: margin-right 4s 1s;

/* property name | duration | easing function */
transition: margin-right 4s ease-in-out;

/* property name | duration | easing function | delay */
transition: margin-right 4s ease-in-out 1s;

/* Apply to 2 properties */
transition: margin-right 4s, color 1s;

/* Apply to all changed properties */
transition: all 0.5s ease-out;

/* Global values */
transition: inherit;
transition: initial;
transition: unset;

The transition property is specified as one or more single-property transitions, separated by commas.

Each single-property transition describes the transition that should be applied to a single property (or the special values all and none). It includes:

• zero or one value representing the property to which the transition should apply. This may be any one of:
  • the keyword none
  • the keyword all
  • a <custom-ident> naming a CSS property.
• zero or one <easing-function> value representing the easing function to use
• zero, one, or two <time> values. The first value that can be parsed as a time is assigned to the transition-duration, and the second value that can be parsed as a time is assigned to transition-delay.

See how things are handled when lists of property values aren't the same length. In short, extra transition descriptions beyond the number of properties actually being animated are ignored.

Formal definition

Formal syntax

<single-transition>#
where 
<single-transition> = [ none | <single-transition-property> ] || <time> || <timing-function> || <time>
where 
<single-transition-property> = all | <custom-ident>
<timing-function> = linear | <cubic-bezier-timing-function> | <step-timing-function>
where 
<cubic-bezier-timing-function> = ease | ease-in | ease-out | ease-in-out | cubic-bezier([0,1]>, <number>, [0,1]>, <number>)
<step-timing-function> = step-start | step-end | steps(<integer>[, <step-position>]?)
where 
<step-position> = jump-start | jump-end | jump-none | jump-both | start | end

Examples

Simple example

This example performs a four-second font size transition with a one-second delay when the user hovers over the element.

HTML

<a class="target">Hover over me</a>

CSS

.target {
  font-size: 14px;
  transition: font-size 4s 1s;
}

.target:hover {
  font-size: 36px;
}

There are several more examples of CSS transitions included in the Using CSS transitions article.

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• Using CSS transitions
• TransitionEvent