<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title><!--引入bootstrap.css样式--><link rel="stylesheet" href="static/plugins/bootstrap-3.4.1/css/bootstrap.css"><style>.centers{/*设置一个编剧为1px的边框 颜色为#dddddd*/border: 1px solid #dddddd;/*设置宽度为400px*/width: 400px;/*设置上下100px，左右居中*/margin-left: auto;margin-right: auto;margin-top: 100px;padding: 20px 40px;/**//*设置border的4个角圆角为5px*/border-radius: 5px;/*设置border的阴影为上下5px左右5px 模糊距离5px颜色为#aaa灰色*/box-shadow: 5px 5px 5px #aaa;}.centers h2{text-align: center;margin-top: 1px;}</style>
</head><body><div class="centers"><h2>用户登录</h2><!--从bootstrap中引入表单-->
<form><div class="form-group"><label for="exampleInputEmail1">用户名</label><input type="email" class="form-control" id="exampleInputEmail1" placeholder="请输入用户名"></div><div class="form-group"><label for="exampleInputPassword1">密码</label><input type="password" class="form-control" id="exampleInputPassword1" placeholder="请输入密码"></div><button type="submit" class="btn btn-primary">登 录</button>
</form>
</div>
</body>
</html>
