Fix bug.

modules/announcement/show.html.erb

@@ -169,6 +169,7 @@
   @media (max-width: 479px){
     .carousel_img_item:nth-child(-n+1){
       display: block;
+      width: 100%;
       float: left;
     }
     .carousel_img_item{
@@ -178,6 +179,7 @@
   @media (min-width: 480px){
     .carousel_img_item:nth-child(-n+2){
       display: block;
+      width: 50%;
       float: left;
     }
     .carousel_img_item{
@@ -197,8 +199,12 @@
   @media (min-width: 1280px){
     .carousel_img_item:nth-child(-n+4){
       display: block;
+      width: 25%;
       float: left;
     }
+    .carousel_img_item{
+      width: 25%;
+    }
   }
 </style>
 <script>