批改状态:合格
老师批语:
定位元素:只要这个元素中有position: relative;或者 position:absolute;就称为定位元素
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta http-equiv="X-UA-Compatible" content="ie=edge"><title>模态框</title><link rel="stylesheet" href="style1.css"></head><body><!-- 页眉 --><header><h2>百度一下</h2><button>登录</button></header><!-- 模态框 --><div class="modal"><!-- 蒙板。用来盖住后面的内容,使其透明化 --><div class="modal-backdrop"></div><div class="modal-body"><button class="close">关闭</button><form action="" method="POST"><table><caption>用户登录</caption><tr><td><label for="name">用户名:</label></td><td><input type="name" name="name" id="name"></td></tr><tr><td><label for="password">密码:</label></td><td><input type="password" name="password" id="password"></td></tr><tr><td><button>登录</button></td></tr></table></form></div></div></body></html>
css
*{margin: 0;padding: 0;box-sizing: border-box;}header {background-color: #ccc;margin: 0.5em 1em;overflow: hidden;}header h2 {float: left;}header button {float:right;width: 10em;height: 2.5em;}header button:hover{cursor: pointer;background-color: #fff;}/* 模态框 *//* 蒙板 */.modal .modal-backdrop{background-color: rgb( 0,0,0,0.5);position: fixed;top: 0;left: 0;right: 0;bottom: 0;}/* 主体 */.modal .modal-body{padding: 1em;min-width: 20em;border: 1px solid #ccc;background: linear-gradient(to right, lightcyan, #fff);/* 固定定位 */position: fixed;top: 5em;right: 20em;left: 20em;}/* 页面初始化时,模态框应该隐藏 *//* .modal {display: none;} */
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