A string representation of the current value.
Throws:
-
DOMException - SYNTAX_ERR: Raised if the specified CSS string value has a syntax
error (according to the attached property) or is unparsable.
INVALID_MODIFICATION_ERR: Raised if the specified CSS string
value represents a different type of values than the values allowed
by the CSS property.
NO_MODIFICATION_ALLOWED_ERR: Raised if this value is readonly.