feat: add dark/light mode switch transition

packages/devtools-ui-kit/src/assets/styles.css

@@ -15,3 +15,21 @@ html.dark {
 ::selection {
   background: #8884;
 }
+
+::view-transition-old(root),
+::view-transition-new(root) {
+  animation: none;
+  mix-blend-mode: normal;
+}
+::view-transition-old(root) {
+  z-index: 1;
+}
+::view-transition-new(root) {
+  z-index: 2147483646;
+}
+.dark::view-transition-old(root) {
+  z-index: 2147483646;
+}
+.dark::view-transition-new(root) {
+  z-index: 1;
+}

packages/devtools-ui-kit/src/components/NDarkToggle.vue

@@ -1,6 +1,5 @@
 <script setup lang="ts">
-import { computed } from 'vue'
-import { useToggle } from '@vueuse/core'
+import { computed, nextTick } from 'vue'
 
 // @ts-expect-error auto imported from @nuxtjs/color-mode
 import { useColorMode } from '#imports'
@@ -14,7 +13,54 @@ const isDark = computed<boolean>({
     mode.preference = isDark.value ? 'light' : 'dark'
   },
 })
-const toggle = useToggle(isDark)
+
+// @ts-expect-error: Transition API
+const isAppearanceTransition = document.startViewTransition
+  && !window.matchMedia('(prefers-reduced-motion: reduce)').matches
+
+/**
+ * Credit to [@hooray](https://github.com/hooray)
+ * @see https://github.com/vuejs/vitepress/pull/2347
+ */
+function toggle(event?: MouseEvent) {
+  if (!isAppearanceTransition || !event) {
+    isDark.value = !isDark.value
+    return
+  }
+
+  const x = event.clientX
+  const y = event.clientY
+  const endRadius = Math.hypot(
+    Math.max(x, innerWidth - x),
+    Math.max(y, innerHeight - y),
+  )
+  // @ts-expect-error: Transition API
+  const transition = document.startViewTransition(async () => {
+    isDark.value = !isDark.value
+    await nextTick()
+  })
+
+  transition.ready.then(() => {
+    const clipPath = [
+      `circle(0px at ${x}px ${y}px)`,
+      `circle(${endRadius}px at ${x}px ${y}px)`,
+    ]
+    document.documentElement.animate(
+      {
+        clipPath: isDark.value
+          ? [...clipPath].reverse()
+          : clipPath,
+      },
+      {
+        duration: 400,
+        easing: 'ease-in',
+        pseudoElement: isDark.value
+          ? '::view-transition-old(root)'
+          : '::view-transition-new(root)',
+      },
+    )
+  })
+}
 const context = {
   mode,
   isDark,

packages/devtools/client/components/DockingPanel.vue

@@ -48,8 +48,8 @@
     </div>
     <div px3 py2 border="b base" flex="~ gap-2">
       <NDarkToggle v-slot="{ toggle, isDark }">
-        <NButton n="sm primary" @click="toggle()">
+        <NButton n="sm primary" @click="toggle">
           <div carbon-sun dark:carbon-moon translate-y--1px /> {{ isDark.value ? 'Dark' : 'Light' }}
         </NButton>
       </NDarkToggle>
       <NButton n="sm primary" to="/settings">

packages/devtools/client/pages/settings.vue

@@ -88,8 +88,8 @@
           </h3>
           <div>
             <NDarkToggle v-slot="{ toggle, isDark }">
-              <NButton n="primary" @click="toggle()">
+              <NButton n="primary" @click="toggle">
                 <div carbon-sun dark:carbon-moon translate-y--1px /> {{ isDark.value ? 'Dark' : 'Light' }}
               </NButton>
             </NDarkToggle>
           </div>

packages/devtools/src/runtime/plugins/view/Container.vue

@@ -76,7 +76,7 @@ function getToggleButtonPosition() {
   background: #0C0C0C;
   border: 1px solid rgba(125,125,125,0.2);
   box-shadow: 3px 5px 10px rgba(0,0,0,0.1);
-  z-index: 2147483647;
+  z-index: 2147483645;
   cursor: pointer;
   opacity: 0.8;
   padding: 0;

packages/devtools/src/runtime/plugins/view/Frame.vue

@@ -255,7 +255,7 @@ declare global {
 <style scoped>
 .nuxt-devtools-frame {
   position: fixed;
-  z-index: 2147483646;
+  z-index: 2147483645;
 }
 
 .nuxt-devtools-frame iframe {