作业内容：

1. 制作一个在线QQ客服的固定定位(QQ客服用图片就行);

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0px;
            padding: 0px;
            box-sizing: border-box;
        }
        body{
            /* position: relative; */
        }
        div img{
            position: fixed;
            right: 0px;
            top: 30px;
        }
        div{
            width: 100%;
            height: 10000px;
            background-color: brown;
        }
    </style>
</head>
<body>
    <div><img src="./1.png" alt=""></div>
</body>
</html>

2. 仿课堂案例写一个三行三列的定位布局, 色块或边框代表内容就可以;

<!DOCTYPE html>
<html lang="zh-CN">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>三行三列布局</title>
  </head>
  <style>
      :root{
          font-size: 10px;
      }
    *{
        margin: 0px;
        padding: 0px;
        box-sizing: border-box;
    }
    body{
        font-size: 16px;
    }
    footer,header{
        height: 5em;
        background-color: thistle;
    }
    .container{
        min-height: calc(100vh - 2 * 5em - 2 * 1rem);
        background-color: tomato;
        position: relative;
        margin:1rem 0px;
    }
    .container aside{
        width: 20rem;
        min-height: inherit;
        position: absolute;
    }
    .container aside:first-child{
        background-color: wheat;
        top: 0px;
        left: 0px;
    }
    .container aside:last-child{
        background-color: yellowgreen;
        top: 0px;
        right: 0px;
    }
    .container main{
        min-height: inherit;
        background-color: blueviolet;
        position: absolute;
        top: 0px;
        left: 21rem;
        right: 21rem;
        margin: 0rem 1rem;
    }
  </style>
  <body>
       <header>页眉</header>
       <div class="container">
           <aside>左侧</aside>
           <main>内容</main>
           <aside>右侧</aside>
       </div>
       <footer>页脚</footer>
  </body>
</html>

固定定位，三行三列定位布局

作业内容：

1. 制作一个在线QQ客服的固定定位(QQ客服用图片就行);

2. 仿课堂案例写一个三行三列的定位布局, 色块或边框代表内容就可以;

3. 将之前落下的作业补齐;

4. 在mdn上预习flex和js的知识,下周要学习.