<!DOCTYPE html>
 <html>
 <head lang="en">
     <meta charset="UTF-8">
     <title></title>
     <link rel="stylesheet" type="text/css" href="style.css">
 </head>
 <body>
 <!--background-attachment:背景图像是否固定或随着随着页面的其他部分滚动
     background-color:设置元素的背景颜色
     background-image:把图片设置为背景
     background-position:设置背景图片的起始位置
     background-repeat:设置背景图片是否及如何重复
     background-size:规定背景图片的尺寸
     background-origin:规定背景图片的定位区域
     background-clip:规定背景的绘制区域
     -->
     <p>测试一下背景颜色是否继承</p>
 </body>
 </html>

 body{
     /*background-color: darkgray;*/
     background-image: url("dear.jpg");
     background-repeat: no-repeat;
     /*background-position:right center;*/
     /*background-position: 100px 100px;*/
     background-attachment: fixed;
 }
 p{
     background-color:olivedrab;
     /*background-image: url("dear.jpg");*/
     width: 200px;
     padding: 10px;
 }

 <!doctype html>
 <html>
 <head>
     <meta charset="utf-8">
     <title></title>
     <link href="style.css" rel="stylesheet" type="text/css">
 </head>
 <body>
 <div>
    <h1>静夜思</h1>
    <h3>李白</h3>
    <h2>窗前明月光</h2>
    <h2>疑是地上霜</h2>
    <h2>举头望明月</h2>
    <h2>低头思故乡</h2>
 </div>
 <div>
     <p id="p1">This is a Intersting World</p>
     <p id="p2">This is a Intersting World</p>
     <p id="p3">This is a Intersting World</p>
     <p id="p4">This is a Intersting World</p>
     <p id="p5">This is a Intersting World</p>
     <p id="p6">This is a Intersting World</p>
     <p id="p7">This is a Intersting World</p>
 </div>
 </body>
 </html>

 body{
     color: aqua;
     text-align: center;
 }
 h3{
     text-indent: 2em;
 }
 #p1{
     text-transform: capitalize;
 }
 #p2{
     text-transform: full-size-kana;
 }
 #p3{
     text-transform: full-width;
 }
 #p4{
     text-transform: lowercase;
 }
 #p5{
     text-transform: uppercase;
 }
 #p6{
     text-shadow: 5px 5px red;
     <!--第三个参数为模糊的距离-->
 }
 #p7{
     width:600px;
     text-wrap: normal;
 }

<body>
    <a href="http://www.jikexueyuan.com">极客学院</a>
</body>

 a:link{
     color:#ff0000;
     text-decoration: none;
     background-color: aqua;
 }
 a:visited{
     color:#00ff00;
 }
 a:hover{
     color: #0000ff;
 }
 a:active{
     color:#ff00ff;
 }

 <body>
     <ul>
         <li>项目1</li>
         <li>项目2</li>
         <li>项目3</li>
         <li>项目4</li>
         <li>项目5</li>
     </ul>

     <ul class="ul1">
         <li>项目1</li>
         <li>项目2</li>
         <li>项目3</li>
         <li>项目4</li>
         <li>项目5</li>
     </ul>

     <ul class="ul2">
         <li>项目1</li>
         <li>项目2</li>
         <li>项目3</li>
         <li>项目4</li>
         <li>项目5</li>
     </ul>
 </body>

ul li{
    /*list-style: circle;*/
    /*list-style-image: url("icon1.gif");*/
}
ul.ul1{
    list-style-position: inside;
}
ul.ul2{
    list-style-position: outside;
}

 <!doctype html>
 <html>
 <head>
     <meta charset="utf-8">
     <title></title>
     <link href="style.css" rel="stylesheet" type="text/css">
 </head>
 <body>
     <table id="tb">
         <tr>
             <th>姓名</th>
             <th>性别</th>
             <th>年龄</th>
         </tr>
         <tr>
             <td>张三</td>
             <td>男</td>
             <td>20</td>
         </tr>
         <tr class="alt">
             <td>李四</td>
             <td>男</td>
             <td>22</td>
         </tr>
         <tr>
             <td>丽丽</td>
             <td>女</td>
             <td>21</td>
         </tr>
         <tr class="alt">
             <td>星星</td>
             <td>女</td>
             <td>24</td>
         </tr>
     </table>
 </body>
 </html>

 #tb{
     border-collapse: collapse;
     width: 500px;
 }
 #tb td,#tb th{
     border: 1px solid bisque;
     padding: 5px;
 }
 #tb th{
     text-align: left;
     background-color: aqua;
     color:#ffffff;
 }
 #tb tr.alt td{
     color:black;
     background-color: aquamarine;
 }