2021年3月13日：
今天学了bootstrap的基本知识，从官网中做了一个很简单的栅格系统：
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Bootstrap 实例 - 列排序</title>
<link rel="stylesheet"
href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://cdn.staticfile.org/jquery/2.1.1/jquery.min.js"></script>
<script
src="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>
<style type="text/css">
.a {
border: 1px solid red;
}
</style>
</head>
<body>
<div class="container">
<div class="row">
<div class="col-12 col-md-8 a">.col-12 .col-md-8</div>
<div class="col-6 col-md-4 a">.col-6 .col-md-4</div>
</div>
<!-- Columns start at 50% wide on mobile and bump up to 33.3% wide on desktop -->
<div class="row">
<div class="col-6 col-md-4 a">.col-6 .col-md-4</div>
<div class="col-6 col-md-4 a">.col-6 .col-md-4</div>
<div class="col-6 col-md-4 a">.col-6 .col-md-4</div>
</div>
<!-- Columns are always 50% wide, on mobile and desktop -->
<div class="row">
<div class="col-6 a">.col-6</div>
<div class="col-6 a">.col-6</div>
</div>
</div>
</body>
</html>
