Use Spans for Inline Elements

说明：

你可以用 span 标签来创建行内元素。还记得我们是怎样使用 .btn-block来创建填满整行的按钮吗？

这张图展示了 inline 元素与 block-level 块级元素的区别：

An 

通过使用 span 元素，你可以把几个元素放在一起。你甚至可以用此为一个元素的不同部分指定样式。

把 "Things cats love" 中的 "love" 放到 span 标签下。然后为其添加 text-danger class 来使文字变成红色。

举例，"Top 3 things cats hate" 元素的写法如下：

<p>Top 3 things cats <span class = "text-danger">hate:</span></p>

原始代码：

<link href="//fonts.gdgdocs.org/css?family=Lobster" rel="stylesheet" type="text/css">
<style>

  h2 {
    font-family: Lobster, Monospace;
  }

  .thick-green-border {
    border-color: green;
    border-width: 10px;
    border-style: solid;
    border-radius: 50%;
  }

</style>

<div class="container-fluid">
  <h2 class="text-primary text-center">CatPhotoApp</h2>

  <a href="#"><img class="img-responsive thick-green-border" src="/images/relaxing-cat.jpg"></a>

  <img src="/images/running-cat.jpg" class="img-responsive">
  <div class="row">
    <div class="col-xs-4">
      <button class="btn btn-block btn-primary">Like</button>
    </div>
    <div class="col-xs-4">
      <button class="btn btn-block btn-info">Info</button>
    </div>
    <div class="col-xs-4">
      <button class="btn btn-block btn-danger">Delete</button>
    </div>
  </div>
  <p>Things cats love:</p>
  <ul>
    <li>cat nip</li>
    <li>laser pointers</li>
    <li>lasagna</li>
  </ul>
  <p>Top 3 things cats hate:</p>
  <ol>
    <li>flea treatment</li>
    <li>thunder</li>
    <li>other cats</li>
  </ol>
  <form action="/submit-cat-photo">
    <label><input type="radio" name="indoor-outdoor"> Indoor</label>
    <label><input type="radio" name="indoor-outdoor"> Outdoor</label>
    <label><input type="checkbox" name="personality"> Loving</label>
    <label><input type="checkbox" name="personality"> Lazy</label>
    <label><input type="checkbox" name="personality"> Crazy</label>
    <input type="text" placeholder="cat photo URL" required>
    <button type="submit">Submit</button>
  </form>
</div>

调试代码：

<link href="//fonts.gdgdocs.org/css?family=Lobster" rel="stylesheet" type="text/css">
<style>

  h2 {
    font-family: Lobster, Monospace;
  }

  .thick-green-border {
    border-color: green;
    border-width: 10px;
    border-style: solid;
    border-radius: 50%;
  }

</style>

<div class="container-fluid">
  <h2 class="text-primary text-center">CatPhotoApp</h2>

  <a href="#"><img class="img-responsive thick-green-border" src="/images/relaxing-cat.jpg"></a>

  <img src="/images/running-cat.jpg" class="img-responsive">
  <div class="row">
    <div class="col-xs-4">
      <button class="btn btn-block btn-primary">Like</button>
    </div>
    <div class="col-xs-4">
      <button class="btn btn-block btn-info">Info</button>
    </div>
    <div class="col-xs-4">
      <button class="btn btn-block btn-danger">Delete</button>
    </div>
  </div>
  <p>Things cats <span class = "text-danger">love</span>:</p>
  <ul>
    <li>cat nip</li>
    <li>laser pointers</li>
    <li>lasagna</li>
  </ul>
  <p>Top 3 things cats hate:</p>
  <ol>
    <li>flea treatment</li>
    <li>thunder</li>
    <li>other cats</li>
  </ol>
  <form action="/submit-cat-photo">
    <label><input type="radio" name="indoor-outdoor"> Indoor</label>
    <label><input type="radio" name="indoor-outdoor"> Outdoor</label>
    <label><input type="checkbox" name="personality"> Loving</label>
    <label><input type="checkbox" name="personality"> Lazy</label>
    <label><input type="checkbox" name="personality"> Crazy</label>
    <input type="text" placeholder="cat photo URL" required>
    <button type="submit">Submit</button>
  </form>
</div>