css sourceMap

@@ -198,7 +198,7 @@ gulp.task('webpack-dev-server', () => {
             },
             },
             autoprefixer: false,
             autoprefixer: false,
             loaders: {
             loaders: {
-                css: ExtractTextPlugin.extract(['css?-url'])
+                css: ExtractTextPlugin.extract(['css?-url&sourceMap'])
             }
             }
         }
         }
     });
     });