<!doctype html>
<html>
<head>
<style>
#target1:is(*)::first-letter {
    background-color: lime;
}

#target2:is(::first-letter) {
    background-color: red;
    content: "cocoa";
}

#target3:is(::before) {
    background-color: red;
    content: "cappuccino";
}

#target4:is(::before, ::after) {
    background-color: red;
    content: "around";
}

#target5:is(::first-letter, p) {
    background-color: lime;
}

#target6:is(nonexistents, :is(nonexistents, ::first-letter)) {
    background-color: red;
}

#target7:is(::before, ::after, *) {
    background-color: lime;
    content: "around";
}

#target8:not(:is(::first-line)) {
    background-color: red;
}

::first-line #target9 {
    background-color: red;
}

:is(::first-line) #target10 {
    background-color: red;
}

#target11:is(::first-line > p) {
    background-color: red;
}

#target12:is(::first-letter, ::after, ::before) {
    background-color: red;
    content: "around";
}

#target12::first-letter {
    background-color: blue !important;
}

#target13:is(::after > span) {
    background-color: red;
    content: "bug";
}

#target14:is(::after) > span {
    background-color: red;
}

#target15:is(::after > span) > span {
    background-color: red;
}

#target16:is(*) > span {
    background-color: lime;
}

</style>
</head>
<body>
<div>
    <p id="target1">pseudo element outside :is has effect.</p>
    <p id="target2">pseudo element inside :is has no effect.</p>
    <p id="target3">pseudo element inside :is has no effect.</p>
    <p id="target4">pseudo element inside :is has no effect.</p>
    <p id="target5">pseudo element inside :is has no effect, so the rest of the selectors should be checked.</p>
    <p id="target6">pseudo element inside nested :is should have no effect.</p>
    <p id="target7">::before/after have no effect.</p>
    <p id="target8">pseudo element inside :not doesn't have effect.</p>
    <p id="target9">::first-line in non-rightmost fragment always unmatch.</p>
    <p id="target10">:is(::first-line) in non-rightmost fragment always unmatches.</p>
    <p id="target11">pseudo element in non-rightmost fragment inside :is always unmatches.</p>
    <p id="target12">first-letter is colored blue.</p>
    <p id="target13">non-rightmost pseudo element has no effect.</p>
    <p id="target14"><span>non-rightmost pseudo element has no effect.</span></p>
    <p id="target15"><span>non-rightmost pseudo element has no effect.</span></p>
    <p id="target16"><span>matchType should be effective for normal element.</span></p>
</div>
</body>
</html>