样式文件导入方法

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="commons.css"/>
</head>
<body>
    <div class="c3">导入style文件测试</div>

</body>
</html>

commons.css文件

#i1 {
    background-color: burlywood;
    height: 48px;
}

.c {
    background-color: red;
    height: 48px;
}

.c2 {
    background-color: blue;
    height: 48px;
}

span {
    background-color: yellowgreen;
    height: 48px;
}

a {
    background-color: blue;
    height: 48px;
}

div span {
    background-color: black;
    color: white;
    height: 48px;
}

.c2 div {
    background-color: yellow;
    font-size: 45px;
    color: red;
    height: 48px;
}

.c2 div div {
    background-color: yellow;
    color: black;
    height: 48px;
}

#i5, #i6, #i7, .c3, .c4 {
    background-color: yellow;
    color: blue;
    height: 48px;
}

input[type='text'] {
    width: 100px;
    height: 200px;
}

.c1[type='zq'] {
    width: 200px;
    height: 200px;
}