revert-layer
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2022.
The revert-layer
CSS-wide keyword rolls back the value of a property in a cascade layer to the value of the property in a CSS rule matching the element in a previous cascade layer. The value of a property with this keyword is recalculated as if no rules were specified on the target element in the current cascade layer.
If there is no other cascade layer to revert to for the matching CSS rule, the property value rolls back to the computed value derived from the current layer. Furthermore, if there is no matching CSS rule in the current layer, the property value for the element rolls back to the style defined in a previous style origin.
This keyword can be applied to any CSS property, including the CSS shorthand property all
.
Revert-layer vs. revert
The revert-layer
keyword lets you rollback styles to those specified in previous cascade layers within the author origin. The revert
keyword, in comparison, lets you roll back styles applied in the author origin to those specified in the user origin or user-agent origin.
The revert-layer
keyword is ideally meant to be applied to properties within a cascade layer. However, if applied to properties outside a cascade layer, it rolls back property values to any values set by presentational hints (such as width
and height
attributes or the <s>
element in HTML), defaulting to the values established by the user agent's stylesheet or user styles. Unlike the revert
keyword, which considers presentational hints as part of the author origin and reverts them as well, the revert-layer
keyword ignores presentational hints outside the cascade layer, so it does not revert them.
Examples
Default cascade layer behavior
In the example below, two cascade layers are defined in the CSS, base
and special
. By default, rules in the special
layer will override competing rules in the base
layer because special
is listed after base
in the @layer
declaration statement.
HTML
<p>This example contains a list.</p>
<ul>
<li class="item feature">Item one</li>
<li class="item">Item two</li>
<li class="item">Item three</li>
</ul>
CSS
@layer base, special;
@layer special {
.item {
color: red;
}
}
@layer base {
.item {
color: blue;
}
.feature {
color: green;
}
}
Result
All the <li>
elements match the item
rule in the special
layer and are red. This is the default cascade layer behavior, where rules in the special
layer take precedence over rules in the base
layer.
Revert to style in previous cascade layer
Let's examine how the revert-layer
keyword changes the default cascade layer behavior. For this example, the special
layer contains an additional feature
rule targeting the first <li>
element. The color
property in this rule is set to revert-layer
.
HTML
<p>This example contains a list.</p>
<ul>
<li class="item feature">Item one</li>
<li class="item">Item two</li>
<li class="item">Item three</li>
</ul>
CSS
@layer base, special;
@layer special {
.item {
color: red;
}
.feature {
color: revert-layer;
}
}
@layer base {
.item {
color: blue;
}
.feature {
color: green;
}
}
Result
With color
set to revert-layer
, the color
property value rolls back to the value in the matching feature
rule in the previous layer base
, and so 'Item one' is now green.
Revert to style in previous origin
This example shows the revert-layer
keyword behavior when there is no cascade layer to revert to and there is no matching CSS rule in the current layer to inherit the property value.
HTML
<p>This example contains a list.</p>
<ul>
<li class="item feature">Item one</li>
<li class="item">Item two</li>
<li class="item">Item three</li>
</ul>
CSS
@layer base {
.item {
color: revert-layer;
}
}
Result
The style for all <li>
elements rolls back to the defaults in the user-agent origin.
Specifications
Specification |
---|
CSS Cascading and Inheritance Level 5 # revert-layer |
Browser compatibility
BCD tables only load in the browser