diff --git a/src/App.vue b/src/App.vue
index b63883ca..a8e2cf09 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -34,7 +34,6 @@
     import VRCXUpdateDialog from './components/dialogs/VRCXUpdateDialog.vue';
 
     import '@/styles/globals.css';
-    import '@/app.css';
 
     console.log(`isLinux: ${LINUX}`);
 
diff --git a/src/app.css b/src/app.css
deleted file mode 100644
index 640e908e..00000000
--- a/src/app.css
+++ /dev/null
@@ -1,32 +0,0 @@
-html {
-    overflow: hidden;
-}
-
-.lucide.is-loading {
-    animation: rotating 2s linear infinite;
-}
-
-.x-container {
-    position: relative;
-    padding: 8px;
-    overflow: hidden auto;
-    box-sizing: border-box;
-    min-width: 0;
-    background: var(--background);
-    height: calc(100% - 20px);
-    margin: 8px 0 8px 0;
-    border-radius: var(--radius);
-    border: 1px solid var(--border);
-}
-
-.aside-collapsed .x-container {
-    margin-right: 8px;
-}
-
-html.dark .x-container {
-    background: var(--sidebar);
-}
-
-[data-sonner-toast] [data-content] [data-description] {
-    white-space: pre-line;
-}
diff --git a/src/styles/fonts.css b/src/styles/fonts.css
index a24560de..a3d5b71f 100644
--- a/src/styles/fonts.css
+++ b/src/styles/fonts.css
@@ -10,3 +10,39 @@
     src: local('Times New Roman');
     unicode-range: U+2026;
 }
+
+:root {
+    --font-western-primary: 'Inter Variable';
+    --font-western:
+        'ellipsis-font', -apple-system, var(--font-western-primary), 'Segoe UI',
+        'Roboto', 'Ubuntu', 'Cantarell', 'DejaVu Sans', sans-serif;
+    --font-symbol: 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';
+    --font-fallback-cjk: sans-serif;
+    --font-primary-cjk:
+        'Noto Sans JP Variable', 'Noto Sans SC Variable',
+        'Noto Sans KR Variable', 'Noto Sans TC Variable';
+}
+
+:root[lang='zh-CN'] {
+    --font-primary-cjk:
+        'Noto Sans SC Variable', 'Noto Sans JP Variable',
+        'Noto Sans KR Variable', 'Noto Sans TC Variable';
+}
+
+:root[lang='ja'] {
+    --font-primary-cjk:
+        'Noto Sans JP Variable', 'Noto Sans KR Variable',
+        'Noto Sans TC Variable', 'Noto Sans SC Variable';
+}
+
+:root[lang='ko'] {
+    --font-primary-cjk:
+        'Noto Sans KR Variable', 'Noto Sans JP Variable',
+        'Noto Sans TC Variable', 'Noto Sans SC Variable';
+}
+
+:root[lang='zh-TW'] {
+    --font-primary-cjk:
+        'Noto Sans TC Variable', 'Noto Sans JP Variable',
+        'Noto Sans KR Variable', 'Noto Sans SC Variable';
+}
diff --git a/src/styles/globals.css b/src/styles/globals.css
index baa05683..f9299d4b 100644
--- a/src/styles/globals.css
+++ b/src/styles/globals.css
@@ -16,30 +16,6 @@
 
 @custom-variant dark (&:is(.dark *));
 
-:root[lang='zh-CN'] {
-    --font-primary-cjk:
-        'Noto Sans SC Variable', 'Noto Sans JP Variable',
-        'Noto Sans KR Variable', 'Noto Sans TC Variable';
-}
-
-:root[lang='ja'] {
-    --font-primary-cjk:
-        'Noto Sans JP Variable', 'Noto Sans KR Variable',
-        'Noto Sans TC Variable', 'Noto Sans SC Variable';
-}
-
-:root[lang='ko'] {
-    --font-primary-cjk:
-        'Noto Sans KR Variable', 'Noto Sans JP Variable',
-        'Noto Sans TC Variable', 'Noto Sans SC Variable';
-}
-
-:root[lang='zh-TW'] {
-    --font-primary-cjk:
-        'Noto Sans TC Variable', 'Noto Sans JP Variable',
-        'Noto Sans KR Variable', 'Noto Sans SC Variable';
-}
-
 :root {
     --background: oklch(1 0 0);
     --foreground: oklch(0.145 0 0);
@@ -95,16 +71,6 @@
     --visibility-public: #22c55e;
     --visibility-friends: #0ea5e9;
     --visibility-private: #ef4444;
-
-    --font-western-primary: 'Inter Variable';
-    --font-western:
-        'ellipsis-font', -apple-system, var(--font-western-primary), 'Segoe UI',
-        'Roboto', 'Ubuntu', 'Cantarell', 'DejaVu Sans', sans-serif;
-    --font-symbol: 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';
-    --font-fallback-cjk: sans-serif;
-    --font-primary-cjk:
-        'Noto Sans JP Variable', 'Noto Sans SC Variable',
-        'Noto Sans KR Variable', 'Noto Sans TC Variable';
 }
 
 .dark {
@@ -202,19 +168,51 @@
     --color-visibility-private: var(--visibility-private);
 }
 
-@layer base {
-    * {
-        @apply border-border outline-ring/50;
-        scrollbar-width: thin;
-        scrollbar-color: var(--border) transparent;
-    }
-    body {
-        @apply bg-background text-foreground;
-        font-family:
-            var(--font-western), var(--font-symbol), var(--font-primary-cjk),
-            var(--font-fallback-cjk);
-        margin: 0;
-    }
+html {
+    overflow: hidden;
+}
+
+.lucide.is-loading {
+    animation: rotating 2s linear infinite;
+}
+
+.x-container {
+    position: relative;
+    padding: 8px;
+    overflow: hidden auto;
+    box-sizing: border-box;
+    min-width: 0;
+    background: var(--background);
+    height: calc(100% - 20px);
+    margin: 8px 0 8px 0;
+    border-radius: var(--radius);
+    border: 1px solid var(--border);
+}
+
+.aside-collapsed .x-container {
+    margin-right: 8px;
+}
+
+html.dark .x-container {
+    background: var(--sidebar);
+}
+
+[data-sonner-toast] [data-content] [data-description] {
+    white-space: pre-line;
+}
+
+* {
+    @apply border-border outline-ring/50;
+    scrollbar-width: thin;
+    scrollbar-color: var(--border) transparent;
+}
+
+body {
+    @apply bg-background text-foreground;
+    font-family:
+        var(--font-western), var(--font-symbol), var(--font-primary-cjk),
+        var(--font-fallback-cjk);
+    margin: 0;
 }
 
 ::-webkit-scrollbar {
@@ -233,17 +231,15 @@
     background-clip: content-box;
 }
 
-@layer utilities {
-    .scrollbar-hidden {
-        scrollbar-width: none;
-        -ms-overflow-style: none;
-    }
+.scrollbar-hidden {
+    scrollbar-width: none;
+    -ms-overflow-style: none;
+}
 
-    .scrollbar-hidden::-webkit-scrollbar {
-        width: 0;
-        height: 0;
-        display: none;
-    }
+.scrollbar-hidden::-webkit-scrollbar {
+    width: 0;
+    height: 0;
+    display: none;
 }
 
 [data-slot='table-header'],
@@ -255,3 +251,31 @@
     width: 1em;
     height: 1em;
 }
+
+/* ==========================================================================
+ * VRCX UI Standards
+ * These are project-wide conventions.
+ * Use them when building new components.
+ * ==========================================================================*/
+
+/* Hover Transitions
+ * Smooth hover state changes to avoid harsh flickering.
+ *   x-hover-card — Cards & panels (0.2s, bg + shadow)
+ *   x-hover-list — List items     (0.15s, bg). Skip for high-density lists (e.g. friend sidebar).
+ *   x-hover-icon — Icon buttons   (0.1s, bg + color)
+ */
+.x-hover-card {
+    transition:
+        background-color 0.2s ease,
+        box-shadow 0.2s ease;
+}
+
+.x-hover-list {
+    transition: background-color 0.15s ease;
+}
+
+.x-hover-icon {
+    transition:
+        background-color 0.1s ease,
+        color 0.1s ease;
+}
diff --git a/src/views/Favorites/FavoritesAvatar.vue b/src/views/Favorites/FavoritesAvatar.vue
index 2a655c69..9a8ae755 100644
--- a/src/views/Favorites/FavoritesAvatar.vue
+++ b/src/views/Favorites/FavoritesAvatar.vue
@@ -51,7 +51,7 @@
                                         v-for="group in favoriteAvatarGroups"
                                         :key="group.key"
                                         :class="[
-                                            'group-item hover:shadow-sm',
+                                            'group-item x-hover-card hover:shadow-sm',
                                             `group-item--${group.visibility}`,
                                             { 'is-active': !hasSearchInput && isGroupActive('remote', group.key) }
                                         ]"
@@ -123,7 +123,7 @@
                                         v-for="group in avatarGroupPlaceholders"
                                         :key="group.key"
                                         :class="[
-                                            'group-item hover:shadow-sm',
+                                            'group-item x-hover-card hover:shadow-sm',
                                             'pointer-events-none opacity-70',
                                             { 'is-active': !hasSearchInput && isGroupActive('remote', group.key) }
                                         ]">
@@ -162,7 +162,7 @@
                                         v-for="group in localAvatarFavoriteGroups"
                                         :key="group"
                                         :class="[
-                                            'group-item hover:shadow-sm',
+                                            'group-item x-hover-card hover:shadow-sm',
                                             { 'is-active': !hasSearchInput && isGroupActive('local', group) }
                                         ]"
                                         @click="handleGroupClick('local', group)">
@@ -211,7 +211,7 @@
                                     :content="t('view.favorite.avatars.local_favorites')">
                                     <div
                                         :class="[
-                                            'group-item hover:shadow-sm',
+                                            'group-item x-hover-card hover:shadow-sm',
                                             'border-dashed flex items-center justify-center gap-2 text-sm',
                                             { 'opacity-50 cursor-not-allowed': !isLocalUserVrcPlusSupporter }
                                         ]"
@@ -253,7 +253,7 @@
                             <div class="flex flex-col gap-2">
                                 <div
                                     :class="[
-                                        'group-item hover:shadow-sm',
+                                        'group-item x-hover-card hover:shadow-sm',
                                         { 'is-active': !hasSearchInput && isGroupActive('history', historyGroupKey) }
                                     ]"
                                     @click="handleGroupClick('history', historyGroupKey)">
@@ -314,7 +314,7 @@
                                         <div
                                             v-for="favorite in avatarFavoriteSearchResults"
                                             :key="favorite.id"
-                                            class="favorites-search-card hover:shadow-sm"
+                                            class="favorites-search-card x-hover-card hover:shadow-sm"
                                             @click="showAvatarDialog(favorite.id)">
                                             <div class="favorites-search-card__content">
                                                 <div
diff --git a/src/views/Favorites/FavoritesFriend.vue b/src/views/Favorites/FavoritesFriend.vue
index d135e006..413e1309 100644
--- a/src/views/Favorites/FavoritesFriend.vue
+++ b/src/views/Favorites/FavoritesFriend.vue
@@ -51,7 +51,7 @@
                                         v-for="group in favoriteFriendGroups"
                                         :key="group.key"
                                         :class="[
-                                            'group-item hover:shadow-sm',
+                                            'group-item x-hover-card hover:shadow-sm',
                                             `group-item--${group.visibility}`,
                                             { 'is-active': !hasSearchInput && isGroupActive('remote', group.key) }
                                         ]"
@@ -140,7 +140,7 @@
                                         v-for="group in localFriendFavoriteGroups"
                                         :key="group"
                                         :class="[
-                                            'group-item hover:shadow-sm',
+                                            'group-item x-hover-card hover:shadow-sm',
                                             { 'is-active': !hasSearchInput && isGroupActive('local', group) }
                                         ]"
                                         @click="handleGroupClick('local', group)">
@@ -184,7 +184,7 @@
                                 </div>
                                 <div
                                     v-if="!isCreatingLocalGroup"
-                                    class="group-item hover:shadow-sm border-dashed flex items-center justify-center gap-2 text-sm"
+                                    class="group-item x-hover-card hover:shadow-sm border-dashed flex items-center justify-center gap-2 text-sm"
                                     @click="startLocalGroupCreation">
                                     <Plus />
                                     <span>{{ t('view.favorite.worlds.new_group') }}</span>
@@ -289,7 +289,7 @@
                                         <div
                                             v-for="favorite in friendFavoriteSearchResults"
                                             :key="favorite.id"
-                                            class="favorites-search-card hover:shadow-sm"
+                                            class="favorites-search-card x-hover-card hover:shadow-sm"
                                             @click="showUserDialog(favorite.id)">
                                             <div class="favorites-search-card__content">
                                                 <div class="favorites-search-card__avatar">
diff --git a/src/views/Favorites/FavoritesWorld.vue b/src/views/Favorites/FavoritesWorld.vue
index 4c6c2e47..34c9c38e 100644
--- a/src/views/Favorites/FavoritesWorld.vue
+++ b/src/views/Favorites/FavoritesWorld.vue
@@ -51,7 +51,7 @@
                                         v-for="group in favoriteWorldGroups"
                                         :key="group.key"
                                         :class="[
-                                            'group-item hover:shadow-sm',
+                                            'group-item x-hover-card hover:shadow-sm',
                                             `group-item--${group.visibility}`,
                                             { 'is-active': !hasSearchInput && isGroupActive('remote', group.key) }
                                         ]"
@@ -123,7 +123,7 @@
                                         v-for="group in worldGroupPlaceholders"
                                         :key="group.key"
                                         :class="[
-                                            'group-item hover:shadow-sm',
+                                            'group-item x-hover-card hover:shadow-sm',
                                             'pointer-events-none opacity-70',
                                             { 'is-active': !hasSearchInput && isGroupActive('remote', group.key) }
                                         ]">
@@ -160,7 +160,7 @@
                                         v-for="group in localWorldFavoriteGroups"
                                         :key="group"
                                         :class="[
-                                            'group-item hover:shadow-sm',
+                                            'group-item x-hover-card hover:shadow-sm',
                                             { 'is-active': !hasSearchInput && isGroupActive('local', group) }
                                         ]"
                                         @click="handleGroupClick('local', group)">
@@ -204,7 +204,7 @@
                                 </div>
                                 <div
                                     v-if="!isCreatingLocalGroup"
-                                    class="group-item hover:shadow-sm border-dashed flex items-center justify-center gap-2 text-sm"
+                                    class="group-item x-hover-card hover:shadow-sm border-dashed flex items-center justify-center gap-2 text-sm"
                                     @click="startLocalGroupCreation">
                                     <Plus />
                                     <span>{{ t('view.favorite.worlds.new_group') }}</span>
@@ -262,7 +262,7 @@
                                         <div
                                             v-for="favorite in worldFavoriteSearchResults"
                                             :key="favorite.id"
-                                            class="favorites-search-card hover:shadow-sm"
+                                            class="favorites-search-card x-hover-card hover:shadow-sm"
                                             @click="showWorldDialog(favorite.id)">
                                             <div class="favorites-search-card__content">
                                                 <div
diff --git a/src/views/Favorites/components/favorites-card.css b/src/views/Favorites/components/favorites-card.css
index 69939122..7b0b327d 100644
--- a/src/views/Favorites/components/favorites-card.css
+++ b/src/views/Favorites/components/favorites-card.css
@@ -12,7 +12,6 @@
     padding: var(--favorites-card-padding-y, 8px)
         var(--favorites-card-padding-x, 8px);
     cursor: pointer;
-    transition: background-color 0.15s ease;
     width: 100%;
     min-width: var(--favorites-card-min-width, 240px);
     max-width: var(--favorites-card-target-width, 320px);
@@ -20,6 +19,7 @@
 
 .favorites-search-card:hover {
     background-color: var(--accent);
+    box-shadow: var(--shadow-sm);
 }
 
 .favorites-search-card__content {
diff --git a/src/views/Favorites/favorites-layout.css b/src/views/Favorites/favorites-layout.css
index 74bd2b18..42697a1c 100644
--- a/src/views/Favorites/favorites-layout.css
+++ b/src/views/Favorites/favorites-layout.css
@@ -22,11 +22,11 @@
     border: 1px solid var(--border);
     padding: 8px;
     cursor: pointer;
-    transition: background-color 0.15s ease;
 }
 
 .group-item:hover {
     background-color: var(--accent);
+    box-shadow: var(--shadow-sm);
 }
 
 .group-item--public {
diff --git a/src/views/FriendsLocations/components/FriendsLocationsCard.vue b/src/views/FriendsLocations/components/FriendsLocationsCard.vue
index 0c57a14e..c9744878 100644
--- a/src/views/FriendsLocations/components/FriendsLocationsCard.vue
+++ b/src/views/FriendsLocations/components/FriendsLocationsCard.vue
@@ -1,7 +1,10 @@
 <template>
     <ContextMenu>
         <ContextMenuTrigger as-child>
-            <Card class="friend-card p-0 gap-0" :style="cardStyle" @click="showUserDialog(friend.id)">
+            <Card
+                class="friend-card x-hover-card p-0 gap-0 hover:bg-accent hover:shadow-sm"
+                :style="cardStyle"
+                @click="showUserDialog(friend.id)">
                 <div class="friend-card__header">
                     <div>
                         <Avatar
@@ -241,16 +244,10 @@
         display: grid;
         gap: calc(14px * var(--card-scale) * var(--card-spacing));
         border-radius: var(--radius-lg);
-        transition: background-color 0.15s ease;
         width: 100%;
         max-width: var(--friend-card-target-width, 220px);
         min-width: var(--friend-card-min-width, 220px);
         box-sizing: border-box;
-
-        &:hover {
-            background-color: var(--accent);
-            box-shadow: var(--shadow-sm);
-        }
     }
 
     .friend-card__header {
diff --git a/src/views/MyAvatars/components/MyAvatarCard.vue b/src/views/MyAvatars/components/MyAvatarCard.vue
index 4bb77991..0c81b9f1 100644
--- a/src/views/MyAvatars/components/MyAvatarCard.vue
+++ b/src/views/MyAvatars/components/MyAvatarCard.vue
@@ -5,7 +5,7 @@
                 <ContextMenuTrigger as="div">
                     <div class="avatar-card-wrapper rounded-lg" @click="$emit('click')">
                         <Card
-                            class="avatar-card flex flex-col gap-0 p-0 cursor-pointer overflow-hidden rounded-lg relative transition-colors hover:bg-accent hover:shadow-md"
+                            class="avatar-card x-hover-card flex flex-col gap-0 p-0 cursor-pointer overflow-hidden rounded-lg relative hover:bg-accent hover:shadow-sm"
                             :class="isActive ? 'border-2 border-primary' : 'border border-border/50'">
                             <div class="w-full aspect-5/2 overflow-hidden bg-muted relative">
                                 <img
diff --git a/src/views/Tools/Tools.vue b/src/views/Tools/Tools.vue
index 36a660a0..223a52b7 100644
--- a/src/views/Tools/Tools.vue
+++ b/src/views/Tools/Tools.vue
@@ -12,7 +12,7 @@
                         <span class="category-title">{{ t('view.tools.pictures.header') }}</span>
                     </div>
                     <div class="tools-grid" v-show="!categoryCollapsed['image']">
-                        <Card class="tool-card p-0 gap-0">
+                        <Card class="tool-card x-hover-card p-0 gap-0 hover:bg-accent hover:shadow-sm">
                             <div class="tool-content text-2xl" @click="showScreenshotMetadataPage">
                                 <div class="tool-icon">
                                     <Camera />
@@ -554,18 +554,12 @@
     }
 
     .tool-card {
-        transition: background-color 0.15s ease;
         position: relative;
         overflow: visible;
         border-radius: var(--radius-lg);
         cursor: pointer;
         width: 100%;
 
-        &:hover {
-            background-color: var(--accent);
-            box-shadow: var(--shadow-sm);
-        }
-
         .tool-content {
             display: flex;
             align-items: center;
diff --git a/src/views/Tools/components/GroupCalendarEventCard.vue b/src/views/Tools/components/GroupCalendarEventCard.vue
index cb21b521..491ce594 100644
--- a/src/views/Tools/components/GroupCalendarEventCard.vue
+++ b/src/views/Tools/components/GroupCalendarEventCard.vue
@@ -2,7 +2,7 @@
     <Popover :open="eventPopoverOpen">
         <PopoverTrigger as-child>
             <Card
-                class="event-card p-0 gap-0"
+                class="event-card x-hover-card p-0 gap-0 hover:bg-accent hover:shadow-sm"
                 :class="cardClass"
                 @mouseenter="openEventPopover"
                 @mouseleave="scheduleCloseEventPopover">
@@ -275,18 +275,12 @@
 
 <style scoped>
     .event-card {
-        transition: background-color 0.15s ease;
         position: relative;
         overflow: visible;
         border-radius: var(--radius-lg);
         width: 100%;
     }
 
-    .event-card:hover {
-        background-color: var(--accent);
-        box-shadow: var(--shadow-sm);
-    }
-
     .event-card.grouped-card {
         margin-bottom: 0;
     }