批改状态:合格
老师批语:完成的不错
<!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>选择器的应用实例</title><style>/* 1. 基本选择器 *//* 1.1 便签选择器 */dd {color: red;}/* 1.2 属性选择器 *//* .attr {color: lightcoral;} */dd[class=attr] {color: lightpink;}/* 2. 上下文选择器 *//* 2.1 父子 */.list > .item {border: thin solid;}/* 2.2 后代 */.list2 .item2 {color: red;}/* 2.3 兄弟(只选取第一个) */.list3 .item3.brother + .item3 {background-color: red;}/* 2.4 同级(除了当前元素的所有同级) */.list4 .item4.brother ~ .item4 {background-color: red;}/* 3. 结构伪类选择器 *//* 匹配第一个 */.order > :nth-child(0n + 1) {background-color: red;}/* 匹配第三个 *//* .order > :nth-child(0n + 3) {background-color: red;} *//* 0乘以任何数得0所以 0n+1 === 1 *//* .order > :nth-child(1) {background-color: blue;} *//* a = 1 匹配一组 */.order > :nth-child(1n +3) {background-color: red;}/* 只获取前三个 *//* a = -1:反向匹配 */.order > :nth-child(-n + 3) {background-color: yellow;}/* 2n 偶数位匹配 */.order > :nth-child(2n) {background-color: gray;}/* 2n+1 奇数匹配 *//* .order > :nth-child(2n + 1) {background-color: gray;} *//* 匹配首个 */.order > :first-child {background-color: blueviolet;}/* 匹配最后一个 */.order > :last-child {background-color: blueviolet;}/* 匹配倒数2个 */.order > :nth-last-child(-1n + 2) {background-color: orange;}/* 4.状态伪类选择器 */fieldset {display: inline-grid;gap : 1em;}/* 4.1 鼠标悬停 提交按钮变灰色*//* 4.2 有效控件 */fieldset :enabled {border-radius: 5px;}/* 4.3 禁用控件 邀请码*/fieldset :disabled {background-color: brown;}/* 4.4 选中控件 记住我*/fieldset :checked + label {color: red;}/* 4.5 必选控件 用户名*/fieldset :required {border-color: red;}/* 4.6 焦点控件 */fieldset button:hover {cursor : pointer;background-color: beige;}</style></head><body><section><dl><dt><h2>1. 基本选择器:</h2></dt><dd>1.1 标签选择器</dd><dd class="attr">1.2 属性选择器</dd></dl><h2>2. 上下文选择器:</h2><h3>2.1 父子 ></h3><ul class="list"><li class="item">itme1</li><li class="item">itme2</li><li class="item">itme3</li><li class="item">itme4</li></ul><h3>2.2 后代 ' '(空格)</h3><ul class="list2"><li class="item2">itme1</li><li class="item2">itme2<ul><li class="item">item2-1<ul><li class="item">item2-1-1</li><li class="item">item2-1-2</li><li class="item">item2-1-3</li></ul></li><li class="item">item2-2</li><li class="item">item2-3</li></ul></li><li class="item2">itme3</li><li class="item2">itme4</li></ul><h3>2.3 兄弟 +</h3><ul class="list3"><li class="item3 brother">itme1</li><li class="item3">itme2</li><li class="item3">itme3</li><li class="item3">itme4</li></ul><h3>2.4 同级 ~</h3><ul class="list4"><li class="item4 brother">itme1</li><li class="item4">itme2</li><li class="item4">itme3</li><li class="item4">itme4</li></ul><h2>3. 结构伪类选择器:</h2><ol class="order"><li class="item">item1</li><li class="item">item2</li><li class="item">item3</li><li class="item">item4</li><li class="item">item5</li><li class="item">item6</li></ol><h2>4. 状态伪类选择器</h2><fieldset><legend>用户注册</legend><input type="text" id="username" name="username" placeholder="用户名" required /><input type="email" id="email" name="email" placeholder="邮箱" /><input type="password" id="password" name="password" placeholder="密码" required /><input type="text" id="vcode" name="vcode" placeholder="邀请码" disabled /><section><input type="checkbox" id="rem" name="remember" checked="checked" /><label for="rem">记住我</label></section><button type="button">提交</button></fieldset></section></body></html>

Copyright 2014-2025 https://www.php.cn/ All Rights Reserved | php.cn | 湘ICP备2023035733号