登录表单、简单后台架构、演示元素样式来源与优先级
part1
<!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>hw03-18</title></head><body><!-- part_1 登录表单 --><form action=""><div class="input"><div><label for="email">邮箱:</label><input type="email" id="email" name="email" value="" placeholder="abc123@example.com"></div><div><label for="pwd">密码:</label><input type="password" id="pwd" name="password" value="" placeholder="请输入密码"></div></div><button>登录</button></form></body></html>

part2
<!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>hw03-18</title><style>body {height: 100vh;width: 100vw;display: grid;grid-template-columns: 10em 1fr;grid-template-rows: 6em 1fr;margin: 0;}body .header {grid-column-end: span 2;border-bottom: 1px solid currentColor;background-color: rgb(0, 0, 0, 0.5);padding: 2em;display: flex;align-items: center;}body .header div {margin-left: auto;}body .nav {background-color: #efc;margin: 0;padding-top: 1em;list-style: none;}body iframe {width: calc(100vw - 10em);height: calc(100vh - 6em);border-left: 1px solid currentColor;}</style></head><body><div class="header"><h1>管理后台</h1><div><span>admin</span><a href="">退出</a></div></div><ul class="nav"><li><a href="https://j.map.baidu.com/b9/yd" target="showBox">地图1</a></li><li><a href="https://j.map.baidu.com/b9/yd" target="showBox">地图2</a></li><li><a href="https://j.map.baidu.com/b9/yd" target="showBox">地图3</a></li><li><a href="https://j.map.baidu.com/b9/yd" target="showBox">地图4</a></li></ul><iframe src="" frameborder="2" name="showBox"></iframe></body></html>

part3
<!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>hw03-18</title><link rel="stylesheet" href="hw1.css"></head><body><h1>Hello</h1><h1 style="color: red;">Hello</h1><h1 style="color: red;"><p style="color: blue;">Hello</p></h1><div class="v1"><h1>Hello</h1></div></body></html>
.v1{color: yellow;}
