feat(ui): Select, dropdown, popover styles & transitions (#11675)

packages/ui/src/components/dropdown-menu.css

@@ -2,26 +2,29 @@
 [data-component="dropdown-menu-sub-content"] {
   min-width: 8rem;
   overflow: hidden;
+  border: none;
   border-radius: var(--radius-md);
-  border: 1px solid color-mix(in oklch, var(--border-base) 50%, transparent);
+  box-shadow: var(--shadow-xs-border);
   background-clip: padding-box;
   background-color: var(--surface-raised-stronger-non-alpha);
   padding: 4px;
-  box-shadow: var(--shadow-md);
-  z-index: 50;
+  z-index: 100;
   transform-origin: var(--kb-menu-content-transform-origin);
 
-  &:focus,
-  &:focus-visible {
+  &:focus-within,
+  &:focus {
     outline: none;
   }
 
-  &[data-closed] {
-    animation: dropdown-menu-close 0.15s ease-out;
+  animation: dropdownMenuContentHide var(--transition-duration) var(--transition-easing) forwards;
+
+  @starting-style {
+    animation: none;
   }
 
   &[data-expanded] {
-    animation: dropdown-menu-open 0.15s ease-out;
+    pointer-events: auto;
+    animation: dropdownMenuContentShow var(--transition-duration) var(--transition-easing) forwards;
   }
 }
 
@@ -38,18 +41,22 @@
     padding: 4px 8px;
     border-radius: var(--radius-sm);
     cursor: default;
-    user-select: none;
     outline: none;
 
     font-family: var(--font-family-sans);
-    font-size: var(--font-size-small);
+    font-size: var(--font-size-base);
     font-weight: var(--font-weight-medium);
     line-height: var(--line-height-large);
     letter-spacing: var(--letter-spacing-normal);
     color: var(--text-strong);
 
-    &[data-highlighted] {
-      background: var(--surface-raised-base-hover);
+    transition-property: background-color, color;
+    transition-duration: var(--transition-duration);
+    transition-timing-function: var(--transition-easing);
+    user-select: none;
+
+    &:hover {
+      background-color: var(--surface-raised-base-hover);
     }
 
     &[data-disabled] {
@@ -61,6 +68,8 @@
   [data-slot="dropdown-menu-sub-trigger"] {
     &[data-expanded] {
       background: var(--surface-raised-base-hover);
+      outline: none;
+      border: none;
     }
   }
 
@@ -102,24 +111,24 @@
   }
 }
 
-@keyframes dropdown-menu-open {
+@keyframes dropdownMenuContentShow {
   from {
     opacity: 0;
-    transform: scale(0.96);
+    transform: scaleY(0.95);
   }
   to {
     opacity: 1;
-    transform: scale(1);
+    transform: scaleY(1);
   }
 }
 
-@keyframes dropdown-menu-close {
+@keyframes dropdownMenuContentHide {
   from {
     opacity: 1;
-    transform: scale(1);
+    transform: scaleY(1);
   }
   to {
     opacity: 0;
-    transform: scale(0.96);
+    transform: scaleY(0.95);
   }
 }