fix for broken paren matching in @keyframes rules

demo/kitchen-sink/docs/css.css

@@ -2,4 +2,29 @@
     font-family: Monaco, "Courier New", monospace;
     font-size: 12px;
     cursor: text;
+}
+
+
+
+.blinker {
+    animation-duration: 1s;
+    animation-name: blink;
+    animation-iteration-count: infinite;
+    nimation-direction: alternate;
+    animation-timing-function: linear;
+}
+
+@keyframes blink {
+    0% {
+        opacity: 0;
+    }
+    40% {
+	    opacity: 0;
+    }
+    40.5% {
+		opacity: 1
+    }
+    100% {
+        opacity: 1
+    }
 }

lib/ace/mode/css_highlight_rules.js

@@ -266,7 +266,7 @@ var CssHighlightRules = function() {
             next:  "ruleset"
         }, {
             token: "string",
-            regex: "@media.*?{",
+            regex: "@.*?{",
             next:  "media"
         },{
             token: "keyword",