src/FelixOnline/Base/ResourceManager.php
public function addCSS($css)
    {
        if (is_array($css)) {
            foreach ($css as $key => $value) {
                if ($this->isLess($css)) {
                    $this->css[] = new FileAsset($css, array(LessphpFilter));
                } elseif ($this->isScss($css)) {
                    $this->css[] = new FileAsset($css, array(ScssphpFilter));
                } else {
                    $this->css[] = new FileAsset($css);
                }
            }
            return $this;
        } else {
            throw new InternalException("CSS files to add is not an array");
        }
    }
public function addCSS($css)
    {
        if (is_array($css)) {
            foreach ($css as $key => $value) {
                if ($this->isLess($css)) {
                    $this->css[] = new FileAsset($css, array(LessphpFilter));
                } elseif ($this->isScss($css)) {
                    $this->css[] = new FileAsset($css, array(ScssphpFilter));
                } else {
                    $this->css[] = new FileAsset($css);
                }
            }
            return $this;
        } else {
            throw new InternalException("CSS files to add is not an array");
        }
    }
/*
Public: Add css files

$css - array of css files to load

Returns css array