我想用第n个子选择第3、第5和第7项
element_name:nth-child(3),element_name:nth-child(5), element_name:nth-child(7)
<!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>
h:nth-child(3) {
background-color: red;
color: blue;
}
h:nth-child(5) {
background-color: blue;
color: azure;
}
h:nth-child(7) {
background-color: forestgreen;
color: #000;
}
</style>
</head>
<body>
<h>heading1</h>
<h>heading2</h>
<h>heading3</h>
<h>heading4</h>
<h>heading5</h>
<h>heading6</h>
<h>heading7</h>
<h>heading8</h>
</body>
</html>