Function substitute_in_element_with_css 

pub fn substitute_in_element_with_css(
    template: &Element,
    scope: &Scope<'_>,
    css: Option<&Stylesheet>,
) -> Element

Substitute the placeholders in a template subtree against scope, then re-run the cascade over the result when a stylesheet is given.

The cascade has to come after substitution for a template whose id or class holds a placeholder: what a rule matches depends on the value that landed there.