preg_replace: highlight css: html,body {margin:0;}

function highlightCSS($s) {
    
    $secret = md5(rand()*rand()*rand()*rand()*time());
    
    // <hidden> = /* ... */
    // <selectors> = html, body, .class, ... ALL TOGETHER
    // <selector> = html OR body OR .class OR ... EACH ONE OF THEM
    // <syntax> = {margin:0; padding:10px; ...}
    // <rule> = margin:0;, padding:10px;, ...
    // <option> = margin, padding, ...
    // <value> = 0, 10px, ...
    
    // create selectors & syntax
    $s = preg_replace( '/(.*?)\{(.*?)\}/i' , '<selectors-' .$secret. '>\1</selectors-' .$secret. '>{<syntax-' .$secret. '>\2</syntax-' .$secret. '>}' , $s );
    $s = str_replace( '/*' , '<span class="hidden">/*' , $s );
    $s = str_replace( '*/' , '*/</span>' , $s );
    
    // selectors
    $s = preg_replace_callback( '/<selectors-' .$secret. '>(.*?)<\/selectors-' .$secret. '>/i' , create_function('$matches' , 'return parent2child( $matches , "selectors-' .$secret. '" , "selector-' .$secret. '" , ",");') , $s );
    $s = preg_replace( '/<selector-' .$secret. '>(.*?)<\/selector-' .$secret. '>/i' , '<span class="selector">\1</span>' , $s );
    
    //syntax
    $s = preg_replace_callback( '/<syntax-' .$secret. '>(.*?)<\/syntax-' .$secret. '>/i' , create_function( '$matches' , 'return parent2child( $matches , "syntax-' .$secret. '" , "rule-' .$secret. '" , ";");' ) , $s );
    $s = preg_replace( '/<rule-' .$secret. '>(.*?):(.*?)<\/rule-' .$secret. '>/i' , '<option-' .$secret. '>\1</option-' .$secret. '>:<value-' .$secret. '>\2</value-' .$secret. '>' , $s );
    $s = preg_replace( '/<option-' .$secret. '>(.*?)<\/option-' .$secret. '>/i' , '<span class="option">\1</span>' , $s );
    $s = preg_replace( '/<value-' .$secret. '>(.*?)<\/value-' .$secret. '>/i' , '<span class="value">\1</span>' , $s );
    
    return $s;
}

body, input, textarea, select, button, table{font-family:Arial,sans-serif; font-size:12px; color:#444444;}

<span class="selector">body</span>, <span class="selector">input</span>, <span class="selector">textarea</span>, <span class="selector">select</span>, <span class="selector">button</span>, <span class="selector">table</span>{<span class="option">font-family</span>:<span class="value">Arial,sans-serif</span>; <span class="option">font-size</span>:<span class="value">12px</span>; <span class="option">color</span>:<span class="value">#444444</span>}