Update item page gradient to be absolute and below cover image, add transitions

assets/transitions.css

@@ -0,0 +1,51 @@
+.slide-enter-active {
+  -moz-transition-duration: 0.1s;
+  -webkit-transition-duration: 0.1s;
+  -o-transition-duration: 0.1s;
+  transition-duration: 0.1s;
+  -moz-transition-timing-function: ease-in;
+  -webkit-transition-timing-function: ease-in;
+  -o-transition-timing-function: ease-in;
+  transition-timing-function: ease-in;
+}
+
+.slide-leave-active {
+  -moz-transition-duration: 0.2s;
+  -webkit-transition-duration: 0.2s;
+  -o-transition-duration: 0.2s;
+  transition-duration: 0.2s;
+  -moz-transition-timing-function: cubic-bezier(0, 1, 0.5, 1);
+  -webkit-transition-timing-function: cubic-bezier(0, 1, 0.5, 1);
+  -o-transition-timing-function: cubic-bezier(0, 1, 0.5, 1);
+  transition-timing-function: cubic-bezier(0, 1, 0.5, 1);
+}
+
+.slide-enter-to,
+.slide-leave {
+  max-height: 600px;
+  overflow: hidden;
+}
+
+.slide-enter,
+.slide-leave-to {
+  overflow: hidden;
+  max-height: 0;
+}
+
+.menu-enter,
+.menu-leave-active {
+  transform: translateY(-15px);
+}
+
+.menu-enter-active {
+  transition: all 0.2s;
+}
+
+.menu-leave-active {
+  transition: all 0.1s;
+}
+
+.menu-enter,
+.menu-leave-active {
+  opacity: 0;
+}