Jak usunąć białe znaki z plików css/styli?

Funkcja zwraca kod css zoptymalizowany pod kątem białych znaków

function css_strip_whitespace($css)
{
  $replace = array(
    "#/\*.*?\*/#s" => "", // Strip C style comments.
    "#\s\s+#" => " ", // Strip excess whitespace.
  );
  $search = array_keys($replace);
  $css = preg_replace($search, $replace, $css);

  $replace = array(
    ": " => ":",
    "; " => ";",
    " {" => "{",
    " }" => "}",
    ", " => ",",
    "{ " => "{",
    ";}" => "}", // Strip optional semicolons.
    ",\n" => ",", // Don't wrap multiple selectors.
    "\n}" => "}", // Don't wrap closing braces.
    "} " => "}\n", // Put each rule on it's own line.
  );
  $search = array_keys($replace);
  $css = str_replace($search, $replace, $css);

  return trim($css);
}