<a href="https://baidu.com/" target="_blank" rel="noopener"><span class="btn btn-primary">我是按钮</span></a>
<a href="https://baidu.com/" target="_blank" rel="noopener"><span class="btn btn-default">我是按钮</span></a>
<a href="https://baidu.com/" target="_blank" rel="noopener"><span class="btn btn-success">我是按钮</span></a>
<a href="https://baidu.com/" target="_blank" rel="noopener"><span class="btn btn-info">我是按钮</span></a>
<a href="https://baidu.com/" target="_blank" rel="noopener"><span class="btn btn-warning">我是按钮</span></a>
<a href="https://baidu.com/" target="_blank" rel="noopener"><span class="btn btn-danger">我是按钮</span></a>
绿色
<div class="alert alert-success block-alert" role="alert">绿色</div>
橙色
<div class="alert alert-warning block-alert" role="alert">橙色</div>
粉色
<div class="alert alert-danger block-alert" role="alert">粉色</div>
蓝色
<div class="alert alert-info block-alert" role="alert">蓝色</div>