<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>DEMO</title>
<style>
    body,html{
      width:100%;
      height:100%;
      margin:0;
      padding:0;
    }
    
  .container {
    display: flex;
    flex-direction: column;
    height: 100%; /* 假设外层容器的高度为视口高度 */
  }

  .container-header {
    height: 100px; /* 头部固定高度 */
    background-color: #ddd;
  }

  .container-body 