<link rel="stylesheet" type="text/css" href="http://www.mysite.com/path/?index.css,common.css">

$filename = $_GET;

foreach($filename as $key => $value){

    $filenameArr = $key;

}

$filenameArr = explode(',' , $filenameArr);

$files = array();

if(count($filenameArr) > 1){

    foreach($filenameArr as $key => $value){

        $arr = explode('_', $value);

        $files[] = $arr[0].'.'.$arr[1];

    }

}else{

    $arr = explode('_', $filenameArr[0]);

    $files[] = $arr[0].'.'.$arr[1];

}

$context = stream_context_create(

    array(

        "http" => array(

            "header" => "User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36",

        )

    )

);

//css声明

header('Content-type: text/css');

$content = '';

foreach($files as $key => $value){

    $content .= iconv("utf-8", "gb2312",file_get_contents('http://www.mysite.com/path/to/' . $value, false, $context));

}

echo $content;