在PHP中清理用户定义的CSS

$user_css = "body {background-color: red;}";
$clean_css = preg_replace('/[^a-zA-Z0-9\s\.,:;#\(\)\[\]]/', '', $user_css);

require_once('vendor/autoload.php');
use Sabberworm\CSS\Parser;

$user_css = "body {background-color: red;}";
$parser = new Parser($user_css);
$css = $parser->parse();

// 遍历CSS对象并删除不需要的属性和选择器
foreach ($css->getAllDeclarationBlocks() as $declarationBlock) {
    foreach ($declarationBlock->getSelectors() as $selector) {
        if (/* 判断选择器是否需要删除 */) {
            $declarationBlock->removeSelector($selector);
        }
    }
    foreach ($declarationBlock->getRules() as $rule) {
        if (/* 判断属性是否需要删除 */) {
            $declarationBlock->removeRule($rule);
        }
    }
}

// 将清理后的CSS转换为字符串
$clean_css = $css->render();

$allowed_selectors = ['body', 'h1', 'h2', 'p'];
$allowed_properties = ['color', 'background-color', 'font-size'];

$user_css = "body {background-color: red;}";
$clean_css = '';

foreach ($allowed_selectors as $selector) {
    $clean_css .= $selector . ' {' . "\n";
    foreach ($allowed_properties as $property) {
        $clean_css .= "\t" . $property . ': ' . $user_css[$selector][$property] . ";\n";
    }
    $clean_css .= '}' . "\n";
}