Hero广告大块屏幕(Jumbotron)
通过引用.jumbotron方法，实现构建超大的Hreo界面，醒目的在网站上展示关键的营销信息，轻量、灵活。
这是一个轻量、灵活的组件，可以选择性地扩展整个视口，以展示您网站上的关键营销信息。
Hello, world!
This is a simple hero unit, a simple jumbotron-style component for calling extra attention to featured content or information.
It uses utility classes for typography and spacing to space content out within the larger container.
<div class="jumbotron">
<h1 class="display-3">Hello, world!</h1>
<p class="lead">This is a simple hero unit, a simple jumbotron-style component for calling extra attention to featured content or information.</p>
<hr class="my-4">
<p>It uses utility classes for typography and spacing to space content out within the larger container.</p>
<p class="lead">
<a class="btn btn-primary btn-lg" href="#" role="button">Learn more</a>
</p>
</div>想要让广告大屏幕占满当前显示浏览器全屏、不带有圆角，只要添加.jumbotron-fluid CSS修饰符，并在里面添加一个.container 或 .container-fluid 内容空间即可。
Fluid jumbotron
This is a modified jumbotron that occupies the entire horizontal space of its parent.
<div class="jumbotron jumbotron-fluid">
<div class="container">
<h1 class="display-4">Fluid jumbotron</h1>
<p class="lead">This is a modified jumbotron that occupies the entire horizontal space of its parent.</p>
</div>
</div>