<!DOCTYPE html>

<html>
<head>
<style>
    body {
        margin: 0;
        height: 2000px;
        overflow: hidden; /* hide scrollbars */
    }

    .group {
        display: inline-block;
        position: relative;
        width: 250px;
        height: 500px;
    }

    .container {
        width: 200px;
        height: 400px;
        outline: 2px solid black;
        border: hidden;
        border-width: 0px;
        border-spacing: 0px !important;
        border-collapse:collapse;
        cellspacing: 0;
        cellpadding: 0;
        padding: 0;
    }

    .box {
        width: 200px;
        height: 198px;
    }

    .sticky {
        position: sticky;
        top: 100px;
        background-color: green;
    }

    .indicator {
        position: absolute;
        top: 0;
        left: 0;
        background-color: red;
    }
</style>
<script>
    function doTest()
    {
        window.scrollTo(0, 100);
    }
    window.addEventListener('load', doTest, false);
</script>
</head>
<body>
    <div class="group">
        <div class="indicator box" style="top: 200px;"></div>
        <table class="container">
            <thead class="sticky">
                <tr>
                    <td class="box"></td>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <td></td>
                </tr>
            </tbody>
        </table>
    </div>

    <div class="group" style="top: 100px">
        <div class="indicator box" style="top: 100px;"></div>
        <table class="container" style="">
            <thead class="sticky">
                <tr>
                    <td class="box"></td>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <td></td>
                </tr>
            </tbody>
        </table>
    </div>

    <div class="group" style="top: 200px">
        <div class="indicator box" style="top: 0;"></div>
        <table class="container" style="">
            <thead class="sticky">
                <tr>
                    <td class="box"></td>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <td></td>
                </tr>
            </tbody>
        </table>
    </div>
    <div style="position: absolute; top: 620px;">
    This test checks that sticky positioned table theads are contained by their table.
    There should be no red.
    </div>
</body>
</html>
