CSSStyleDeclaration.setProperty()

The CSSStyleDeclaration.setProperty() method interface sets a new value for a property on a CSS style declaration object.

Inputs: propertyName A string representing the CSS property name (hyphen case) to be modified. value A string containing the new property value. If not specified, treated as the empty string. A null value is treated the same as the empty string (“”). Note: value must not contain “!important”, that should be set using the priority parameter. priority A string allowing the CSS priority to be set to important. Only the values listed below are accepted: “important” (case-insensitive) for setting the property as !important; “”, undefined, or null for removing the !important flag if present.