With :is and :where it is trivial to trick selectors :is(selector_1, :where(selector_2)) Has always the specificity of selector_2, and if you choose an imposs

With :is and :where it is trivial to trick selectors :is(selector_1, :where(selector_2)) Has always the specificity of selector_2, and if you choose an impossible selector for selector_1 (the easiest approach is to give multiple ids or use non existent classes/elements) it only select by selector_2