remove unused styles

default_app/index.html

@@ -129,25 +129,6 @@
       background-color: rgba(194, 245, 255, 0.3);
       border-radius: 50%;
     }
-
-    #holder {
-      display: flex;
-      flex: 1;
-      align-items: center;
-      justify-content: center;
-      border: 1px solid #e0e5e6;
-      background-color: #f6f8f8;
-      color: #466a72;
-      border-radius: 3px;
-      font-size: 30px;
-      font-weight: 300;
-      cursor: default;
-      -webkit-user-select: none;
-    }
-
-    #holder.hover {
-      border-color: #2ab0cb;
-    }
   </style>
 </head>