diff --git a/timer.js b/timer.js
index 050717f..bbc0e25 100644
--- a/timer.js
+++ b/timer.js
@@ -11,6 +11,7 @@
             infobox.innerHTML = "失敗…";
             infobox.setAttribute("class", "failure")
 	    areas[hit].removeEventListener("click", stopCountDown, false);
+	    document.body.style.background = "#191970";
         } else {
             infobox.innerHTML = count + "秒前";
             tmID = setTimeout(countDown, 1000);