webui: css transitions

one/static/style/box.less

@@ -273,13 +273,17 @@
             z-index: 2;
             position: relative;
         }
+        .details {
+            height: auto;
+        }
     }
     &.opened #new-folder-form {
         display: block;
     }
     .details {
-        border-top: 1px solid #888;
-        display: none;
+        height: 0px;
+        -webkit-transition: height 700ms;
+        overflow: hidden;
         .container {
             padding: 5px 5px;
             .upload-zone {
@@ -314,6 +318,9 @@
         a {
             text-decoration: underline;
         }
+        .details-container {
+            border-top: 1px solid #888;
+        }
         .name {
             float: none;
             background-image: url(/static/icons/computer.png);