jQuery子选择器未按预期工作

here's my markup:

这是我的标记：

<div class=widget>
    <div class=panel>panel1</div>
    <div class=panel>panel2
        <div class=widget>
            <div class=panel>panel1</div>
            <div class=panel>panel2</div>
        </div>
    </div>
</div>
<div class=widget