diff --git a/src/client/ui/default.vue b/src/client/ui/default.vue
index 7065b345fd..d896f32307 100644
--- a/src/client/ui/default.vue
+++ b/src/client/ui/default.vue
@@ -1,8 +1,8 @@
 <template>
-<div class="mk-app" v-hotkey.global="keymap">
+<div class="mk-app" v-hotkey.global="keymap" :class="{ wallpaper }">
 	<XSidebar ref="nav" class="sidebar"/>
 
-	<div class="contents" ref="contents" :class="{ wallpaper }">
+	<div class="contents" ref="contents">
 		<header class="header" ref="header" @contextmenu.prevent.stop="onContextmenu" @click="onHeaderClick">
 			<XHeader :info="pageInfo"/>
 		</header>
@@ -269,19 +269,18 @@ export default defineComponent({
 	// ほんとは単に 100vh と書きたいところだが... https://css-tricks.com/the-trick-to-viewport-units-on-mobile/
 	min-height: calc(var(--vh, 1vh) * 100);
 	box-sizing: border-box;
-
 	display: flex;
 
+	&.wallpaper {
+		background: var(--wallpaperOverlay);
+		//backdrop-filter: blur(4px);
+	}
+
 	> .contents {
 		width: 100%;
 		min-width: 0;
 		padding-top: $header-height;
 
-		&.wallpaper {
-			background: var(--wallpaperOverlay);
-			//backdrop-filter: blur(4px);
-		}
-
 		> .header {
 			position: fixed;
 			z-index: 1000;