<div class="container mt-3">
  <p>字体大小会随着屏幕的变化而变化，可以重置浏览器大小查看效果。</p>
  <h1>h1 Bootstrap 标题</h1>
  <h2>h2 Bootstrap 标题</h2>
  <h3>h3 Bootstrap 标题</h3>
  <h4>h4 Bootstrap 标题</h4>
  <h5>h5 Bootstrap 标题</h5>
  <h6>h6 Bootstrap 标题</h6>
</div>

<div class="container mt-3">
  <p>字体大小会随着屏幕的变化而变化，可以重置浏览器大小查看效果。</p>
  <p class="h1">h1 Bootstrap 标题</p>
  <p class="h2">h2 Bootstrap 标题</p>
  <p class="h3">h3 Bootstrap 标题</p>
  <p class="h4">h4 Bootstrap 标题 </p>
  <p class="h5">h5 Bootstrap 标题</p>
  <p class="h6">h6 Bootstrap 标题</p>
</div>

<div class="container mt-3">
  <h1>Display 标题</h1>
  <p>Display 标题可以输出更大更粗的字体样式。</p>
  <h1 class="display-1">Display 1</h1>
  <h1 class="display-2">Display 2</h1>
  <h1 class="display-3">Display 3</h1>
  <h1 class="display-4">Display 4</h1>
  <h1 class="display-5">Display 5</h1>
  <h1 class="display-6">Display 6</h1>
</div>

<div class="container mt-3">
  <h1>更小文本标题</h1>
  <p>small 元素用于字号更小的颜色更浅的文本:</p>       
  <h1>h1 标题 <small>副标题</small></h1>
  <h2>h2 标题 <small>副标题</small></h2>
  <h3>h3 标题 <small>副标题</small></h3>
  <h4>h4 标题 <small>副标题</small></h4>
  <h5>h5 标题 <small>副标题</small></h5>
  <h6>h6 标题 <small>副标题</small></h6>
</div>

<div class="container mt-3">
  <h1>高亮文本</h1>    
  <p>用 mark 元素(或 .mark 类)来 <mark>高亮</mark> 文本。</p>
</div>

<div class="container mt-3">
  <h1>关注博主</h1>
  <p>大家一起加油，努力学技术</p>
  <p>要保持<abbr title="World Health Organization">自信</abbr>呀，少年！！</p>
</div>

<div class="container mt-3">
  <h1>Blockquotes</h1>
  <p>The blockquote element is used to present content from another source:</p>
  <blockquote class="blockquote">
    <p>For 50 years, WWF has been protecting the future of nature. The world's leading conservation organization, WWF works in 100 countries and is supported by 1.2 million members in the United States and close to 5 million globally.</p>
    <footer class="blockquote-footer">From WWF's website</footer>
  </blockquote>
</div>

<div class="container mt-3">
  <h1>Description Lists</h1>    
  <p>The dl element indicates a description list:</p>
  <dl>
    <dt>Coffee</dt>
    <dd>- black hot drink</dd>
    <dt>Milk</dt>
    <dd>- white cold drink</dd>
  </dl>     
</div>

<div class="container mt-3">
  <h1>Code Snippets</h1>
  <p>Inline snippets of code should be embedded in the code element:</p>
  <p>The following HTML elements: <code>span</code>, <code>section</code>, and <code>div</code> defines a section in a document.</p>
</div>

<div class="container mt-3">
  <h1>Keyboard Inputs</h1>
  <p>To indicate input that is typically entered via the keyboard, use the kbd element:</p>
  <p>Use <kbd>ctrl + p</kbd> to open the Print dialog box.</p>
</div>

<div class="container mt-3">
    <h1>Multiple Code Lines</h1>
    <p>For multiple lines of code, use the pre element:</p>
    <pre>
        Text in a pre element
        is displayed in a fixed-width
        font, and it preserves
        both      spaces and
        line breaks.
    </pre>
</div>

<div class="container mt-3">
  <div class="container">
  <h2>代表指定意义的文本颜色</h2>
  <p class="text-muted">柔和的文本。</p>
  <p class="text-primary">重要的文本。</p>
  <p class="text-success">执行成功的文本。</p>
  <p class="text-info">代表一些提示信息的文本。</p>
  <p class="text-warning">警告文本。</p>
  <p class="text-danger">危险操作文本。</p>
  <p class="text-secondary">副标题。</p>
  <p class="text-dark">深灰色文字。</p>
  <p class="text-body">默认颜色，为黑色。</p>
  <p class="text-light">浅灰色文本（白色背景上看不清楚）。</p>
  <p class="text-white">白色文本（白色背景上看不清楚）。</p>
  </div>
</div>

<div class="container mt-3">
  <h2>文本颜色透明度</h2>
  <p>可以设置文本颜色透明度为 50% ，使用 .text-black-50 或 .text-white-50 类:</p>
  <p class="text-black-50">透明度为 50% 的黑色文本，背景为白色。</p>
  <p class="text-white-50 bg-dark">透明度为 50% 的白色文本，背景为黑色。</p>
</div>

<div class="container mt-3">
  <div class="container">
  <h2>背景颜色</h2>
  <p class="bg-primary text-white">重要的背景颜色。</p>
  <p class="bg-success text-white">执行成功背景颜色。</p>
  <p class="bg-info text-white">信息提示背景颜色。</p>
  <p class="bg-warning text-white">警告背景颜色</p>
  <p class="bg-danger text-white">危险背景颜色。</p>
  <p class="bg-secondary text-white">副标题背景颜色。</p>
  <p class="bg-dark text-white">黑色背景颜色。</p>
  <p class="bg-light text-dark">浅灰背景颜色。</p>
  </div>
</div>