diff --git a/src/sandbox/patchers/css.ts b/src/sandbox/patchers/css.ts
index b5a9480..5b93c86 100644
--- a/src/sandbox/patchers/css.ts
+++ b/src/sandbox/patchers/css.ts
@@ -135,7 +135,7 @@ class ScopedCSS {
     }
 
     // handle grouping selector, a,span,p,div { ... }
-    cssText = cssText.replace(/^[^]+{/, selectors =>
+    cssText = cssText.replace(/^[\s\S]+{/, selectors =>
       selectors.replace(/(^|,\n?)([^,]+)/g, (item, p, s) => {
         // handle div,body,span { ... }
         if (rootSelectorRE.test(item)) {