LayoutTests/fast/element-targeting/resources/subframe.html

<!DOCTYPE html>
<html>
<head>
<style>
.grid {
    display: grid;
    grid-template-rows: [header] 20px [title] auto [body] auto [button] 30px;
    grid-gap: 20px;

    width: 300px;
    padding: 12px;
    border-radius: 10px;
    border: 1px solid lightgray;
    font-family: system-ui;
}

.grid + .grid {
    margin-top: 1em;
}

.header {
    grid-row: header;
}

.title {
    grid-row: title;

    font-size: 1.1em;
    font-weight: bold;
    word-break: keep-all;
}

.body {
    grid-row: body;
}

.button {
    grid-row: button;

    appearance: none;
    border-radius: 5px;
    border: none;
    background: royalblue;
    color: white;
    font-size: 16px;
}
</style>
</head>
<body>
<div class="grid">
    <div class="header">one</div>
    <div class="title">two</div>
    <div class="description">three</div>
    <button class="button">four</button>
</div>
<script>
const grid = document.querySelector(".grid");
grid.appendChild(grid.children[0]);
grid.appendChild(grid.children[1]);
</script>
</body>
</html>