<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <?php require_once 'css.html'; ?>
</head>
<body>
<div style="width:90% ;margin: 0 auto;">
    <h2>B李化云管理系统 v1.0</h2>
    <nav class="navbar navbar-default" role="navigation">
        <div class="container-fluid">