1.iframe
<!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>后台</title><style>@import url('./static/css/admin.css');</style></head><body><!-- <figure><figcaption>导航</figcaption><div class="first"><a href="https://j.map.baidu.com/d0/Bhdu" target="city">合肥市</a><a href="https://j.map.baidu.com/45/g" target="city">上海市</a><a href="https://j.map.baidu.com/fe/J" target="city">杭州市</a></div><div class="seconde"><iframe src="./static/images/girl.jpg" frameborder="0" name="city" width="1000px" height="1000px"></iframe></div></figure> --><header><h1>网站后台管理系统</h1><section><em>admin</em><button onclick="location.href='logout.php'">退出</button></section></header><nav><a href="../1017/demo1.html" target="content">元素属性</a><a href="../1017/demo2.html" target="content">布局元素</a><a href="../1017/demo3.html" target="content">图文列表</a><a href="../1017/demo4.html" target="content">图片链接与列表</a><a href="../1017/demo5.html" target="content">细说表格</a><a href="../1018/demo1.html" target="content">表单元素与控件</a><a href="demo1.html" target="content">音频与视频元素</a></nav><iframe src="" name="content"></iframe></body></html>
a的target和iframe的name一一对应
2.选择器
<!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>音频</title><style>p{background-color: red;}</style></head><body><video src="./static/images/test.mp4" controls autoplay muted loop poster="static/images/girl.jpg"></video><audio src="" controls autoplay muted></audio><p>aaa</p><p>bbb</p><p>ccc</p></body></html>