Astra_Minify::render_css()

		private static function render_css() {

			self::load_filesystem();

			if ( ! defined( 'FS_CHMOD_FILE' ) ) {
				define( 'FS_CHMOD_FILE', ( fileperms( ABSPATH . 'index.php' ) & 0777 | 0644 ) );
			}

			if ( get_option( 'ast-theme-css-status' ) ) {
				$assets_status = self::clear_assets_cache();

				if ( false == $assets_status ) {
					return false;
				}
			}

			$cache_dir   = self::get_cache_dir();
			$new_css_key = str_replace( '.', '-', uniqid( '', true ) );
			$css_slug    = self::_asset_slug();
			$css_files   = self::get_css_files();
			$css         = '';
			$css_min     = '';
			$filepath    = $cache_dir['path'] . $css_slug . '-' . $new_css_key . '.css';

			if ( count( $css_files ) > 0 ) {

				foreach ( $css_files as $k => $file ) {

					if ( ! empty( $file ) && file_exists( $file ) ) {
						$css .= self::$astra_addon_filesystem->get_contents(
							$file,
							FS_CHMOD_FILE
						);
					}
				}
			}

			$css = apply_filters( 'astra_render_css', $css );

			$status = self::$astra_addon_filesystem->put_contents(
				$filepath,
				$css,
				FS_CHMOD_FILE
			);

			$status = ! $status;

			// Save the new css key.
			update_option( 'ast-theme-css-status', $status );
			update_option( self::$_css_key . '-' . $css_slug, $new_css_key );
		}