diff --git a/src/resources/beeping/style.css b/src/resources/beeping/style.css
index 891646c..acc4494 100644
--- a/src/resources/beeping/style.css
+++ b/src/resources/beeping/style.css
@@ -123,11 +123,11 @@ button:hover {
     width: 10em;
 }
 
-.invalid {
-    background-color: #dd7979
+#time-input.invalid {
+    background-color: #dd7979!
 }
 
-.invalid:hover {
+#time-input.invalid:hover {
     background-color: #c56161
 }