feat: improved modal animations

client/js/components/anchor.vue

 <template lang="pug">
-  .modal(v-bind:class='{ "is-active": isShown }')
-    .modal-background
+  transition(:duration="400")
+    .modal(v-show='isShown', v-cloak)
+      transition(name='modal-background')
+        .modal-background(v-show='isShown')
       .modal-container
-      .modal-content
+        transition(name='modal-content')
+          .modal-content(v-show='isShown')
             header.is-blue
               span Copy link to this section
             section

client/js/components/modal-create-page.vue

 <template lang="pug">
-  .modal(v-bind:class='{ "is-active": isShown }')
-    .modal-background
+  transition(:duration="400")
+    .modal(v-show='isShown', v-cloak)
+      transition(name='modal-background')
+        .modal-background(v-show='isShown')
       .modal-container
-      .modal-content
+        transition(name='modal-content')
+          .modal-content(v-show='isShown')
             header.is-light-blue Create New Document
             section
               label.label Enter the new document path:

client/js/components/modal-move-page.vue

 <template lang="pug">
-  .modal(v-bind:class='{ "is-active": isShown }')
-    .modal-background
+  transition(:duration="400")
+    .modal(v-show='isShown', v-cloak)
+      transition(name='modal-background')
+        .modal-background(v-show='isShown')
       .modal-container
-      .modal-content
+        transition(name='modal-content')
+          .modal-content(v-show='isShown')
             header.is-indigo Move document
             section
               label.label Enter the new document path:

client/scss/components/modal.scss

 .modal {
 	align-items: flex-start;
-	display: none;
-
-	&.is-active {
 	display: block;
-	}
 
 	&.is-superimposed {
 		.modal-background {
@@ -23,8 +19,15 @@
 	height: 100vh;
 	position: fixed;
 	background-color: rgba(0,0,0,0.85);
-	animation: .4s ease fadeIn;
 	z-index: 10;
+
+  &-enter-active {
+    animation: .4s ease fadeIn;
+  }
+  &-leave-active {
+    animation: .4s ease fadeOut;
+  }
+
 }
 .modal-container {
 	position: fixed;
@@ -38,10 +41,16 @@
 	align-items: center;
 }
 .modal-content {
-	animation: .3s ease zoomIn;
 	width: 600px;
 	background-color: #FFF;
 
+  &-enter-active {
+    animation: .3s ease zoomIn;
+  }
+  &-leave-active {
+    animation: .3s ease zoomOut;
+  }
+
 	&.is-expanded {
 		align-self: stretch;
 		width: 100%;