The attr() CSS function is used to retrieve the value of an attribute of the selected element and use it in the stylesheet. It can also be used on pseudo-elements, in which case the value of the attribute on the pseudo-element's originating element is returned....attr(src url); attr(data-count number); attr(data-width px); /* With...fallback */ attr(data-count number, 0); attr(src url, ""); attr(data-width...