The CSSPropertyRule interface of the CSS Properties and Values API represents a single CSS @property rule.

Inherits properties from its ancestor CSSRule.

CSSPropertyRule.inherits Read only

Returns the inherit flag of the custom property.

CSSPropertyRule.initialvalue Read only

Returns the initial value of the custom property.

CSSPropertyRule.name Read only

Returns the name of the custom property.

CSSPropertyRule.syntax Read only

Returns the literal syntax of the custom property.

No specific methods; inherits methods from its ancestor CSSRule.

This stylesheet contains a single @property rule. The first CSSRule returned will be a CSSPropertyRule with the properties and values as defined by the rule in CSS.

@property --property-name {
  syntax: "<color>";
  inherits: false;
  initial-value: #c0ffee;
}

let myRules = document.styleSheets[0].cssRules;
console.log(myRules[0]); //a CSSPropertyRule