Tools/TestWebKitAPI/Tests/WebKitCocoa/element-targeting-8.html

<!DOCTYPE html>
<html lang="en">
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
body, html, main {
    margin: 0;
    width: 100%;
    height: 100%;
}

section {
    display: inline-block;
}
</style>
<script>
addEventListener("load", () => {
    const outerShadowRoot = document.querySelector("main").attachShadow({ mode: "open" });
    outerShadowRoot.innerHTML = `
        <style>
            section {
                width: 400px;
                height: 600px;
                border: 2px solid black;
            }
        </style>
        <section></section>`;

    const innerShadowRoot = outerShadowRoot.querySelector("section").attachShadow({ mode: "open" });
    innerShadowRoot.innerHTML = `
        <style>
            div {
                width: 400px;
                height: 200px;
                box-sizing: border-box;
            }
            .red { background-color: rgb(255, 59, 48); }
            .green { background-color: rgb(52, 199, 89); }
            .blue { background-color: rgb(0, 122, 255); }
        </style>
        <div class="red"></div>
        <div class="green"></div>
        <div class="blue"></div>`;
});
</script>
</head>
<body>
<main></main>
</body>
</html>