1.opacity
<!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>Document</title>
<style>
div {
width: 400px;
height: 400px;
background-color: green;
opacity: 0.5;
}
</style>
</head>
<body>
<div>
<img src="./images/product.png" alt="">
这个字透明吗
</div>
</body>
</html>
2. 边框合并
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
table {
border: 1px solid #000;
/* 注意: 一定要加给table标签 : 做细线表格 */
border-collapse: collapse;
}
th,
td {
border: 1px solid #000;
}
</style>
</head>
<body>
<!-- border="1" width="400" height="300"cellspacing="0" -->
<table>
<caption><h3>前端与移动开发学员学习情况</h3></caption>
<thead>
<tr>
<th>编号</th>
<th>姓名</th>
<th>性别</th>
<th>成绩</th>
</tr>
</thead>
<tbody>
<tr>
<td>1</td>
<td>小姐姐</td>
<td>女</td>
<td>100</td>
</tr>
<tr>
<td>2</td>
<td>小哥哥</td>
<td>男</td>
<td>100</td>
</tr>
<tr>
<td>3</td>
<td>大姐姐</td>
<td>女</td>
<td>100</td>
</tr>
</tbody>
<tfoot>
<tr>
<td colspan="2">总成绩</td>
<td colspan="2">300</td>
</tr>
</tfoot>
</table>
</body>
</html>
3.书写三角形
<!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>Document</title>
<style>
div {
/* width: 100px;
height: 100px; */
width: 0;
height: 0;
/* background-color: pink; */
/* transparent: 透明 */
border-top: 10px solid transparent;
border-right: 10px solid transparent;
border-bottom: 10px solid transparent;
border-left: 10px solid orange;
}
/*
1. 书写一个盒子
2. 盒子添加四个方向的border, 颜色设置不同
3. 保留其中一个方向的border, 其他方向颜色是transparent
*/
</style>
</head>
<body>
<div></div>
</body>
</html>
4.焦点伪类选择器
<!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>Document</title>
<style>
/* 获得焦点的状态 */
/* 获得焦点: 把光标点到input里面; 失去焦点: 把光标从input里面拿出来 */
input:focus {
background-color: pink;
}
</style>
</head>
<body>
<input type="text">
<input type="password">
<input type="button">
</body>
</html>
5.属性选择器
<!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>Document</title>
<style>
/* text:背景色是粉色; password背景色是skyblue */
input[type='text'] {
background-color: pink;
}
input[type="password"] {
background-color: skyblue;
}
/* input:nth-child(1) {} */
</style>
</head>
<body>
<input type="text">
<input type="password">
</body>
</html>
6.链接伪类选择器
