initial-value
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The initial-value
CSS descriptor is required when using the @property
at-rule
unless the syntax accepts any valid token stream. It sets the initial-value for the property.
The value chosen as the initial-value
must parse correctly according to the syntax definition. Therefore, if syntax is <color>
then the initial-value must be a valid color
value.
Syntax
@property --property-name {
syntax: '<color>';
inherits: false;
initial-value: #c0ffee;
}
@property --property-name {
syntax: '<color>';
inherits: true;
initial-value: #c0ffee;
}
Values
A string with a value which is a correct value for the chosen syntax
.
Formal definition
Related at-rule | @property |
---|---|
Initial value | n/a (required) |
Computed value | as specified |
Formal syntax
Examples
Add type checking to --my-color
custom property
, as a color, the initial-value being a valid color:
@property --my-color {
syntax: '<color>';
inherits: false;
initial-value: #c0ffee;
}
Using JavaScript CSS.registerProperty
:
window.CSS.registerProperty({
name: '--my-color',
syntax: '<color>',
inherits: false,
initialValue: '#c0ffee',
});
Specifications
Specification |
---|
CSS Properties and Values API Level 1 # initial-value-descriptor |
Browser compatibility
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