The cssText property of the CSSRule interface returns the actual text of a CSSStyleSheet style-rule.
Note: Do not confuse this property with element-style CSSStyleDeclaration.cssText.
Be aware that this property used to be mutable but is now read-only. Attempting to set it does absolutely nothing, and doesn't even emit a warning or error. Furthermore, it has no settable sub-properties. Therefore, to modify it, use the stylesheet's cssRules[index] properties .selectorText and .style (or its sub-properties). See Using dynamic styling information for details.
A string containing the actual text of the CSSStyleSheet rule.
body {
background-color: darkblue;
}let stylesheet = document.styleSheets[0];
console.log(stylesheet.cssRules[0].cssText); // body { background-color: darkblue; }