diff --git a/src/vue-ctk-date-time-picker/assets/animation.scss b/src/vue-ctk-date-time-picker/assets/animation.scss
index c960e967..1d9126ee 100644
--- a/src/vue-ctk-date-time-picker/assets/animation.scss
+++ b/src/vue-ctk-date-time-picker/assets/animation.scss
@@ -1,21 +1,25 @@
 /** Slide animation **/
 .slide-enter-active, .slide-leave-active {
   opacity: 1;
+  z-index: 999;
   transition: all 0.3s;
   transform: translateY(0);
 }
 .slide-enter, .slide-leave-to /* .fade-leave-active below version 2.1.8 */ {
   opacity: 0;
+  z-index: 999;
   transform: translateY(-20px);
 }
 /** Slide animation **/
 .slideinvert-enter-active, .slideinvert-leave-active {
   opacity: 1;
+  z-index: 999;
   transition: all 0.3s;
   transform: translateY(0);
 }
 .slideinvert-enter, .slideinvert-leave-to /* .fade-leave-active below version 2.1.8 */ {
   opacity: 0;
+  z-index: 999;
   transform: translateY(40px);
 }
 /** Slide next/prev animation  **/