SOURCE

<h2>响应式卡片</h2>

<div class="polaroid">
  <img src="https://www.runoob.com/try/demo_source/rock600x400.jpg" alt="Norway" style="width:100%">
  <div class="container">
    <p>The Troll's tongue in Hardanger, Norway</p>
  </div>
</div>

<div class="polaroid">
  <img src="https://www.runoob.com/try/demo_source/lights600x400.jpg" alt="Norway" style="width:100%">
  <div class="container">
    <p>Northern Lights in Norway</p>
  </div>
</div>

body {margin:25px;}

div.polaroid {
  width: 80%;
  background-color: white;
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
  margin-bottom: 25px;
}

div.container {
  text-align: center;
  padding: 10px 20px;
}