diff --git a/src/client/components/modal-page-window.vue b/src/client/components/modal-page-window.vue
index 3ca7c31e0e..cb81a974f5 100644
--- a/src/client/components/modal-page-window.vue
+++ b/src/client/components/modal-page-window.vue
@@ -10,7 +10,7 @@
 			</span>
 			<button class="_button" @click="$refs.modal.close()"><i class="fas fa-times"></i></button>
 		</div>
-		<div class="body _flat_">
+		<div class="body _fitSide_">
 			<keep-alive>
 				<component :is="component" v-bind="props" :ref="changePage"/>
 			</keep-alive>
diff --git a/src/client/components/page-window.vue b/src/client/components/page-window.vue
index 904d13e0e8..7d15c75d62 100644
--- a/src/client/components/page-window.vue
+++ b/src/client/components/page-window.vue
@@ -16,7 +16,7 @@
 	<template #headerLeft>
 		<button v-if="history.length > 0" class="_button" @click="back()" v-tooltip="$ts.goBack"><i class="fas fa-arrow-left"></i></button>
 	</template>
-	<div class="yrolvcoq _flat_">
+	<div class="yrolvcoq _fitSide_">
 		<component :is="component" v-bind="props" :ref="changePage"/>
 	</div>
 </XWindow>
diff --git a/src/client/components/ui/folder.vue b/src/client/components/ui/folder.vue
index cc3da083c5..d0616a57c1 100644
--- a/src/client/components/ui/folder.vue
+++ b/src/client/components/ui/folder.vue
@@ -154,7 +154,7 @@ export default defineComponent({
 	}
 }
 
-._flat_ .ssazuxis {
+._fitSide_ .ssazuxis {
 	> header {
 		padding: 0 16px;
 	}
diff --git a/src/client/components/ui/info.vue b/src/client/components/ui/info.vue
index 4dc6b58373..e16f2736f1 100644
--- a/src/client/components/ui/info.vue
+++ b/src/client/components/ui/info.vue
@@ -43,7 +43,7 @@ export default defineComponent({
 	}
 }
 
-._flat_ .fpezltsf {
+._fitSide_ .fpezltsf {
 	border-radius: 0;
 }
 </style>
diff --git a/src/client/pages/user/index.vue b/src/client/pages/user/index.vue
index f34c42797a..0ddf73d572 100644
--- a/src/client/pages/user/index.vue
+++ b/src/client/pages/user/index.vue
@@ -827,7 +827,7 @@ export default defineComponent({
 	}
 }
 
-._flat_ .ftskorzw.narrow {
+._fitSide_ .ftskorzw.narrow {
 	> .profile {
 		> .warn {
 			margin: 0;
diff --git a/src/client/style.scss b/src/client/style.scss
index 1c8807573b..d6bad5a24d 100644
--- a/src/client/style.scss
+++ b/src/client/style.scss
@@ -380,7 +380,7 @@ hr {
 	}
 }
 
-._flat_ {
+._fitSide_ {
 	--root-margin: 0px;
 	--baseContentWidth: 100%;
 	--panelBorder: none;
diff --git a/src/client/ui/chat/side.vue b/src/client/ui/chat/side.vue
index d920e5b77c..3fd0a0e77b 100644
--- a/src/client/ui/chat/side.vue
+++ b/src/client/ui/chat/side.vue
@@ -3,7 +3,7 @@
 	<header class="header" @contextmenu.prevent.stop="onContextmenu">
 		<MkHeader class="title" :info="pageInfo" :center="false"/>
 	</header>
-	<component :is="component" v-bind="props" :ref="changePage" class="body _flat_"/>
+	<component :is="component" v-bind="props" :ref="changePage" class="body _fitSide_"/>
 </div>
 </template>
 
diff --git a/src/client/ui/deck/main-column.vue b/src/client/ui/deck/main-column.vue
index 2127444769..baf88a9721 100644
--- a/src/client/ui/deck/main-column.vue
+++ b/src/client/ui/deck/main-column.vue
@@ -7,7 +7,7 @@
 		</template>
 	</template>
 
-	<router-view v-slot="{ Component }" class="_flat_">
+	<router-view v-slot="{ Component }" class="_fitSide_">
 		<transition>
 			<keep-alive :include="['timeline']">
 				<component :is="Component" :ref="changePage" @contextmenu.stop="onContextmenu"/>
diff --git a/src/client/ui/default.vue b/src/client/ui/default.vue
index 69668ff96d..3518b1a91a 100644
--- a/src/client/ui/default.vue
+++ b/src/client/ui/default.vue
@@ -13,7 +13,7 @@
 		</template>
 
 		<main class="main" @contextmenu.stop="onContextmenu" :style="{ background: pageInfo?.bg }">
-			<div class="content" :class="{ _flat_: !fullView }">
+			<div class="content" :class="{ _fitSide_: !fullView }">
 				<router-view v-slot="{ Component }">
 					<transition :name="$store.state.animation ? 'page' : ''" mode="out-in" @enter="onTransition">
 						<keep-alive :include="['timeline']">
diff --git a/src/client/widgets/notifications.vue b/src/client/widgets/notifications.vue
index 01c76850d8..b0245eed6a 100644
--- a/src/client/widgets/notifications.vue
+++ b/src/client/widgets/notifications.vue
@@ -3,7 +3,7 @@
 	<template #header><i class="fas fa-bell"></i>{{ $ts.notifications }}</template>
 	<template #func><button @click="configure()" class="_button"><i class="fas fa-cog"></i></button></template>
 
-	<div class="_flat_">
+	<div class="_fitSide_">
 		<XNotifications :include-types="props.includingTypes"/>
 	</div>
 </MkContainer>