diff --git a/src/public/less/app.less b/src/public/less/app.less
index 290fca4..1f866ce 100644
--- a/src/public/less/app.less
+++ b/src/public/less/app.less
@@ -8,8 +8,14 @@ body {
 }
 
 .thumbnail-selected {
-    border-color: @brand-primary;
-    background-color: @brand-primary;
+    transition: border 400ms ease-in-out;
+    animation-name: select-thumbnail;
+    animation-duration: 400ms;
+    animation-fill-mode: forwards;
+}
+@keyframes select-thumbnail {
+    0%   { background-color: @gray-light;    }
+    100% { background-color: @brand-primary; }
 }
 
 .clickable {