Html Material Design Lite-卡片支持文本在网格内时不随较大卡片扩展

我正在尝试使用MDL构建一个网站。但是，在网格中使用卡片时，当卡片比行中的其他卡片小时，卡片操作不会与底部对齐，如下所示：

看起来，支持文本并没有像我希望的那样扩展，但不确定我是如何做到这一点的。以下是HTML中的相关片段：

<!-- Content -->
<main class="mdl-layout__content">
    <div class="mdl-grid">

        <!-- Short supporting text -->
        <div class="home-card mdl-cell mdl-cell--4-col mdl-cell--8-col-tablet mdl-card mdl-shadow--2dp">
            <div class="mdl-card__title">
                <h2 class="mdl-card__title-text">Blog</h2>
            </div>
            <div class="mdl-card__supporting-text">
                A fairly recent addition detailing some of the work done on current projects.
            </div>
            <div class="mdl-card__actions mdl-card--border">
                <a class="mdl-button mdl-button--colored mdl-js-button mdl-js-ripple-effect">Visit Blog</a>
            </div>
            <div class="mdl-card__menu">
                <button class="mdl-button mdl-button--icon mdl-js-button mdl-js-ripple-effect">
                    <i class="material-icons">share</i>
                </button>
            </div>
        </div>

        <!-- Long supporting text -->
        <div class="home-card mdl-cell mdl-cell--4-col mdl-cell--8-col-tablet mdl-card mdl-shadow--2dp">
            <div class="mdl-card__title">
                <h2 class="mdl-card__title-text">Blog</h2>
            </div>
            <div class="mdl-card__supporting-text">
                A fairly recent addition detailing some of the work done on current projects.
                A fairly recent addition detailing some of the work done on current projects.
            </div>
            <div class="mdl-card__actions mdl-card--border">
                <a class="mdl-button mdl-button--colored mdl-js-button mdl-js-ripple-effect">Visit Blog</a>
            </div>
            <div class="mdl-card__menu">
                <button class="mdl-button mdl-button--icon mdl-js-button mdl-js-ripple-effect">
                    <i class="material-icons">share</i>
                </button>
            </div>
        </div>
    </div>
</main>

---

德普。添加

mdl卡--将
扩展到支持文本div是我所需要的

<div class="mdl-card__supporting-text mdl-card--expand">
    A fairly recent addition detailing some of the work done on current projects.
</div>


一个相当新的补充，详细说明了当前项目中所做的一些工作。

<div class="mdl-card__supporting-text mdl-card--expand">
    A fairly recent addition detailing some of the work done on current projects.
</div>