feat: add circular reveal animation to theme toggle using View Transitions API

web/src/app.css

@@ -77,9 +77,6 @@ html,
 body {
   @apply font-inter overflow-x-hidden;
   color: var(--color-text-primary);
-  transition:
-    background-color 0.3s ease-in-out,
-    color 0.3s ease-in-out;
 }
 
 body {
@@ -87,19 +84,6 @@ body {
   background-color: var(--color-bg-primary);
 }
 
-/* Smooth theme transitions for all elements */
-*:not(canvas):not([class*="animate-"]) {
-  transition-property: background-color, border-color, color, fill, stroke;
-  transition-duration: 0.3s;
-  transition-timing-function: ease-in-out;
-}
-
-/* Elements with explicit transition classes should extend, not replace */
-[class*="transition-colors"],
-[class*="transition-all"] {
-  transition-duration: 0.3s !important;
-}
-
 html:not(.dark) {
   .os-scrollbar {
     --os-handle-bg: rgba(0, 0, 0, 0.25) !important;
@@ -120,7 +104,7 @@ html.dark {
   border-radius: 4px;
 }
 
-/* Native scrollbars (Webkit: Chrome, Safari, Edge) */
+/* Native scrollbars for other elements (Webkit: Chrome, Safari, Edge) */
 html:not(.dark) ::-webkit-scrollbar {
   width: 10px;
   height: 10px;
@@ -167,25 +151,46 @@ html.dark ::-webkit-scrollbar-thumb:active {
   background: rgba(255, 255, 255, 0.55);
 }
 
-/* Native scrollbars (Firefox) */
-html:not(.dark) {
-  scrollbar-color: rgba(0, 0, 0, 0.25) rgba(0, 0, 0, 0.05);
+/* Native scrollbars for other elements (Firefox) - applied to a wrapper class */
+.native-scrollbar {
   scrollbar-width: thin;
 }
 
-html.dark {
+html:not(.dark) .native-scrollbar {
+  scrollbar-color: rgba(0, 0, 0, 0.25) rgba(0, 0, 0, 0.05);
+}
+
+html.dark .native-scrollbar {
   scrollbar-color: rgba(255, 255, 255, 0.35) rgba(255, 255, 255, 0.05);
-  scrollbar-width: thin;
+}
+
+/* Hide native scrollbar on html/body - OverlayScrollbars handles body scrolling */
+/* Must come AFTER general scrollbar styles to win via cascade */
+html,
+body {
+  scrollbar-width: none; /* Firefox */
+  -ms-overflow-style: none; /* IE/Edge */
+}
+
+html::-webkit-scrollbar,
+body::-webkit-scrollbar {
+  display: none; /* Chrome, Safari, Opera */
 }
 
 /* Utility class for page main wrapper */
 .page-main {
-  @apply relative min-h-screen text-zinc-900 dark:text-zinc-50 transition-colors duration-300;
+  @apply relative min-h-screen text-zinc-900 dark:text-zinc-50;
 }
 
-/* View Transitions API - page transition animations */
+/* View Transitions API - theme toggle animation */
+/* Disable default cross-fade so JS can animate clip-path instead */
+::view-transition-old(root),
+::view-transition-new(root) {
+  animation: none;
+  mix-blend-mode: normal;
+}
 
-/* Persistent elements (background with dots, theme toggle) - excluded from transition */
+/* Persistent elements (background with dots, theme toggle) - excluded from page transitions */
 /* Hide old snapshots entirely so only the live element shows (prevents doubling/ghosting) */
 ::view-transition-old(background),
 ::view-transition-old(theme-toggle) {
@@ -220,12 +225,6 @@ html.dark {
   }
 }
 
-/* Only animate page content, not root (persistent UI stays static) */
-::view-transition-old(root),
-::view-transition-new(root) {
-  animation: none;
-}
-
 ::view-transition-old(page-content) {
   animation: vt-slide-to-left 250ms cubic-bezier(0.4, 0, 0.2, 1) both;
 }

web/src/app.html

@@ -9,9 +9,10 @@
       body {
         scrollbar-width: none; /* Firefox */
         -ms-overflow-style: none; /* IE/Edge */
-        &::-webkit-scrollbar {
-          display: none; /* Chrome, Safari, Opera */
       }
+      html::-webkit-scrollbar,
+      body::-webkit-scrollbar {
+        display: none; /* Chrome, Safari, Opera */
       }
     </style>
     <script>

web/src/lib/components/Clouds.svelte

@@ -879,9 +879,7 @@
 <!-- Wrapper for background + ASCII clouds canvas -->
 <div class="pointer-events-none fixed inset-0 -z-20" {style}>
   <!-- Background overlay (also serves as fallback when WebGL fails) -->
-  <div
-    class="absolute inset-0 bg-white dark:bg-black transition-colors duration-300"
-  ></div>
+  <div class="absolute inset-0 bg-white dark:bg-black"></div>
 
   <!-- ASCII Clouds canvas (hidden if WebGL failed) -->
   {#if !webglFailed}

web/src/lib/components/Dots.svelte

@@ -409,9 +409,7 @@
 <!-- Wrapper for background + dots canvas - single persistent unit -->
 <div class="pointer-events-none fixed inset-0 -z-20" {style}>
   <!-- Background overlay -->
-  <div
-    class="absolute inset-0 bg-white dark:bg-black transition-colors duration-300"
-  ></div>
+  <div class="absolute inset-0 bg-white dark:bg-black"></div>
 
   <!-- Dots canvas -->
   <canvas

web/src/lib/components/ThemeToggle.svelte

@@ -1,22 +1,86 @@
 <script lang="ts">
+  import { tick } from "svelte";
   import { themeStore } from "$lib/stores/theme.svelte";
   import { telemetry } from "$lib/telemetry";
   import IconSun from "~icons/lucide/sun";
   import IconMoon from "~icons/lucide/moon";
 
-  function handleToggle() {
+  /**
+   * Theme toggle with View Transitions API circular reveal animation.
+   * The clip-path circle expands from the click point to cover the viewport.
+   */
+  async function handleToggle(event: MouseEvent) {
     const newTheme = themeStore.isDark ? "light" : "dark";
+
+    const supportsViewTransition =
+      typeof document !== "undefined" &&
+      "startViewTransition" in document &&
+      !window.matchMedia("(prefers-reduced-motion: reduce)").matches;
+
+    if (!supportsViewTransition) {
       themeStore.toggle();
       telemetry.track({
         name: "theme_change",
         properties: { theme: newTheme },
       });
+      return;
+    }
+
+    // Calculate animation origin from click coordinates
+    const x = event.clientX;
+    const y = event.clientY;
+    const endRadius = Math.hypot(
+      Math.max(x, innerWidth - x),
+      Math.max(y, innerHeight - y),
+    );
+
+    // Remove view-transition-names so all elements are captured in root snapshot
+    // (named elements would otherwise appear through "holes" in the circular reveal)
+    const elementsWithVTN = document.querySelectorAll(
+      '[style*="view-transition-name"]',
+    );
+    const savedStyles: Array<{ el: Element; style: string }> = [];
+    elementsWithVTN.forEach((el) => {
+      savedStyles.push({ el, style: el.getAttribute("style") || "" });
+      (el as HTMLElement).style.viewTransitionName = "none";
+    });
+    void document.documentElement.offsetHeight;
+
+    const transition = document.startViewTransition(async () => {
+      themeStore.toggle();
+      await tick();
+    });
+
+    transition.ready.then(() => {
+      document.documentElement.animate(
+        {
+          clipPath: [
+            `circle(0px at ${x}px ${y}px)`,
+            `circle(${endRadius}px at ${x}px ${y}px)`,
+          ],
+        },
+        {
+          duration: 500,
+          easing: "cubic-bezier(0.4, 0, 0.2, 1)",
+          pseudoElement: "::view-transition-new(root)",
+        },
+      );
+    });
+
+    await transition.finished;
+
+    // Restore original view-transition-name styles
+    savedStyles.forEach(({ el, style }) => {
+      el.setAttribute("style", style);
+    });
+
+    telemetry.track({ name: "theme_change", properties: { theme: newTheme } });
   }
 </script>
 
 <button
   type="button"
-  onclick={handleToggle}
+  onclick={(e) => handleToggle(e)}
   aria-label={themeStore.isDark
     ? "Switch to light mode"
     : "Switch to dark mode"}

web/src/routes/+layout.svelte

@@ -153,6 +153,6 @@
 {/if}
 
 <!-- Page content wrapper - this is what transitions between pages -->
-<div class="pb-12" style="view-transition-name: page-content">
+<div style="view-transition-name: page-content">
   {@render children()}
 </div>

web/src/routes/+page.svelte

@@ -26,7 +26,7 @@
   }
 </script>
 
-<main class="page-main overflow-x-hidden font-schibsted">
+<main class="page-main overflow-x-hidden font-schibsted pb-12">
   <div class="flex items-center flex-col pt-14">
     <div
       class="max-w-2xl mx-4 border-b border-zinc-200 dark:border-zinc-700 divide-y divide-zinc-200 dark:divide-zinc-700 sm:mx-6"

web/src/routes/admin/+layout.svelte

@@ -56,9 +56,7 @@
   {@render children()}
 {:else}
   <!-- Admin layout with sidebar -->
-  <div
-    class="pointer-events-none fixed inset-0 -z-20 bg-admin-bg transition-colors duration-300"
-  ></div>
+  <div class="pointer-events-none fixed inset-0 -z-20 bg-admin-bg"></div>
   <Sidebar
     projectCount={stats?.totalProjects ?? 0}
     tagCount={stats?.totalTags ?? 0}

web/src/routes/admin/login/+page.svelte

@@ -38,9 +38,7 @@
   <title>Admin Login | xevion.dev</title>
 </svelte:head>
 
-<div
-  class="pointer-events-none fixed inset-0 -z-20 bg-admin-bg transition-colors duration-300"
-></div>
+<div class="pointer-events-none fixed inset-0 -z-20 bg-admin-bg"></div>
 <main class="page-main text-admin-text">
   <div class="flex min-h-screen items-center justify-center px-4">
     <div class="w-full max-w-md space-y-4">