diff --git a/src/client/components/form/base.vue b/src/client/components/form/base.vue
index 249b49c675..b2e429d6bf 100644
--- a/src/client/components/form/base.vue
+++ b/src/client/components/form/base.vue
@@ -20,12 +20,16 @@ export default defineComponent({
 
 <style lang="scss" scoped>
 .rbusrurv {
+	// 他のCSSからも参照されるので消さないように
+	--formXPadding: 32px;
+	--formYPadding: 32px;
+
 	line-height: 1.4em;
 	background: var(--bg);
-	padding: 32px;
+	padding: var(--formYPadding) var(--formXPadding);
 
 	&:not(.wide).max-width_400px {
-		padding: 32px 0;
+		--formXPadding: 0px;
 
 		> ::v-deep(*) {
 			._formPanel {
diff --git a/src/client/components/form/form.scss b/src/client/components/form/form.scss
index c7f4373544..d9486430be 100644
--- a/src/client/components/form/form.scss
+++ b/src/client/components/form/form.scss
@@ -10,9 +10,17 @@
 }
 
 ._formLabel {
+	position: sticky;
+	top: var(--stickyTop, 0px);
+	background: var(--bg);
+	z-index: 2;
 	font-size: 80%;
-	padding: 0 16px 8px 16px;
-	opacity: 0.8;
+	margin: -8px calc(var(--formXPadding) * -1) 0 calc(var(--formXPadding) * -1);
+	padding: 8px calc(16px + var(--formXPadding)) 8px calc(16px + var(--formXPadding));
+	color: var(--fgTransparentWeak);
+	background: var(--X17);
+	-webkit-backdrop-filter: blur(10px);
+	backdrop-filter: blur(10px);
 
 	&:empty {
 		display: none;
diff --git a/src/client/components/global/a.vue b/src/client/components/global/a.vue
index a8a597b2bb..7ad62a7310 100644
--- a/src/client/components/global/a.vue
+++ b/src/client/components/global/a.vue
@@ -93,6 +93,10 @@ export default defineComponent({
 			os.pageWindow(this.to);
 		},
 
+		modalWindow() {
+			os.modalPageWindow(this.to);
+		},
+
 		popout() {
 			popout(this.to);
 		},
@@ -111,6 +115,8 @@ export default defineComponent({
 			if (this.behavior) {
 				if (this.behavior === 'window') {
 					return this.window();
+				} else if (this.behavior === 'modalWindow') {
+					return this.modalWindow();
 				}
 			}
 
diff --git a/src/client/components/modal-page-window.vue b/src/client/components/modal-page-window.vue
new file mode 100644
index 0000000000..a9a5c0ce57
--- /dev/null
+++ b/src/client/components/modal-page-window.vue
@@ -0,0 +1,211 @@
+<template>
+<MkModal ref="modal" @click="$emit('click')" @closed="$emit('closed')">
+	<div class="hrmcaedk _popup _narrow_" :style="{ width: `${width}px`, height: (height ? `min(${height}px, 100%)` : '100%') }">
+		<div class="header">
+			<button class="_button" @click="back()" v-if="history.length > 0"><Fa :icon="faChevronLeft"/></button>
+			<button class="_button" style="pointer-events: none;" v-else><!-- マージンのバランスを取るためのダミー --></button>
+			<span class="title">
+				<XHeader :info="pageInfo" :with-back="false"/>
+			</span>
+			<button class="_button" @click="$refs.modal.close()"><Fa :icon="faTimes"/></button>
+		</div>
+		<div class="body _flat_">
+			<component :is="component" v-bind="props" :ref="changePage"/>
+		</div>
+	</div>
+</MkModal>
+</template>
+
+<script lang="ts">
+import { defineComponent } from 'vue';
+import { faExternalLinkAlt, faExpandAlt, faLink, faChevronLeft, faColumns, faTimes } from '@fortawesome/free-solid-svg-icons';
+import MkModal from '@client/components/ui/modal.vue';
+import XHeader from '@client/ui/_common_/header.vue';
+import { popout } from '@client/scripts/popout';
+import copyToClipboard from '@client/scripts/copy-to-clipboard';
+import { resolve } from '@client/router';
+import { url } from '@client/config';
+import * as symbols from '@client/symbols';
+
+export default defineComponent({
+	components: {
+		MkModal,
+		XHeader,
+	},
+
+	inject: {
+		sideViewHook: {
+			default: null
+		}
+	},
+
+	provide() {
+		return {
+			navHook: (path) => {
+				this.navigate(path);
+			}
+		};
+	},
+
+	props: {
+		initialPath: {
+			type: String,
+			required: true,
+		},
+		initialComponent: {
+			type: Object,
+			required: true,
+		},
+		initialProps: {
+			type: Object,
+			required: false,
+			default: () => {},
+		},
+	},
+
+	emits: ['closed'],
+
+	data() {
+		return {
+			width: 850,
+			height: 650,
+			pageInfo: null,
+			path: this.initialPath,
+			component: this.initialComponent,
+			props: this.initialProps,
+			history: [],
+			faChevronLeft, faTimes,
+		};
+	},
+
+	computed: {
+		url(): string {
+			return url + this.path;
+		},
+
+		contextmenu() {
+			return [{
+				type: 'label',
+				text: this.path,
+			}, {
+				icon: faExpandAlt,
+				text: this.$ts.showInPage,
+				action: this.expand
+			}, this.sideViewHook ? {
+				icon: faColumns,
+				text: this.$ts.openInSideView,
+				action: () => {
+					this.sideViewHook(this.path);
+					this.$refs.window.close();
+				}
+			} : undefined, {
+				icon: faExternalLinkAlt,
+				text: this.$ts.popout,
+				action: this.popout
+			}, null, {
+				icon: faExternalLinkAlt,
+				text: this.$ts.openInNewTab,
+				action: () => {
+					window.open(this.url, '_blank');
+					this.$refs.window.close();
+				}
+			}, {
+				icon: faLink,
+				text: this.$ts.copyLink,
+				action: () => {
+					copyToClipboard(this.url);
+				}
+			}];
+		},
+	},
+
+	methods: {
+		changePage(page) {
+			if (page == null) return;
+			if (page[symbols.PAGE_INFO]) {
+				this.pageInfo = page[symbols.PAGE_INFO];
+			}
+		},
+
+		navigate(path, record = true) {
+			if (record) this.history.push(this.path);
+			this.path = path;
+			const { component, props } = resolve(path);
+			this.component = component;
+			this.props = props;
+		},
+
+		back() {
+			this.navigate(this.history.pop(), false);
+		},
+
+		expand() {
+			this.$router.push(this.path);
+			this.$refs.window.close();
+		},
+
+		popout() {
+			popout(this.path, this.$el);
+			this.$refs.window.close();
+		},
+	},
+});
+</script>
+
+<style lang="scss" scoped>
+.hrmcaedk {
+	overflow: hidden;
+	display: flex;
+	flex-direction: column;
+	contain: content;
+
+	--root-margin: 24px;
+
+	@media (max-width: 500px) {
+		--root-margin: 16px;
+	}
+
+	> .header {
+		$height: 54px;
+		$height-narrow: 42px;
+		display: flex;
+		flex-shrink: 0;
+		box-shadow: 0px 1px var(--divider);
+
+		> button {
+			height: $height;
+			width: $height;
+
+			@media (max-width: 500px) {
+				height: $height-narrow;
+				width: $height-narrow;
+			}
+		}
+
+		> .title {
+			flex: 1;
+			line-height: $height;
+			padding-left: 32px;
+			font-weight: bold;
+			white-space: nowrap;
+			overflow: hidden;
+			text-overflow: ellipsis;
+			pointer-events: none;
+
+			@media (max-width: 500px) {
+				line-height: $height-narrow;
+				padding-left: 16px;
+			}
+		}
+
+		> button + .title {
+			padding-left: 0;
+		}
+	}
+
+	> .body {
+		overflow: auto;
+		background: var(--bg);
+	}
+}
+</style>
diff --git a/src/client/components/ui/modal-window.vue b/src/client/components/ui/modal-window.vue
index ca17ae6093..90b803801d 100644
--- a/src/client/components/ui/modal-window.vue
+++ b/src/client/components/ui/modal-window.vue
@@ -1,6 +1,6 @@
 <template>
 <MkModal ref="modal" @click="$emit('click')" @closed="$emit('closed')">
-	<div class="ebkgoccj _popup _narrow_" @keydown="onKeydown" :style="{ width: `${width}px`, height: height ? `${height}px` : null }">
+	<div class="ebkgoccj _popup _narrow_" @keydown="onKeydown" :style="{ width: `${width}px`, height: scroll ? (height ? `${height}px` : null) :  (height ? `min(${height}px, 100%)` : '100%') }">
 		<div class="header">
 			<button class="_button" v-if="withOkButton" @click="$emit('close')"><Fa :icon="faTimes"/></button>
 			<span class="title">
@@ -61,6 +61,11 @@ export default defineComponent({
 			required: false,
 			default: true,
 		},
+		scroll: {
+			type: Boolean,
+			required: false,
+			default: true,
+		},
 	},
 
 	emits: ['click', 'close', 'closed', 'ok'],
diff --git a/src/client/os.ts b/src/client/os.ts
index e1707531de..b159cf509d 100644
--- a/src/client/os.ts
+++ b/src/client/os.ts
@@ -203,6 +203,15 @@ export function pageWindow(path: string) {
 	}, {}, 'closed');
 }
 
+export function modalPageWindow(path: string) {
+	const { component, props } = resolve(path);
+	popup(import('@client/components/modal-page-window.vue'), {
+		initialPath: path,
+		initialComponent: markRaw(component),
+		initialProps: props,
+	}, {}, 'closed');
+}
+
 export function dialog(props: Record<string, any>) {
 	return new Promise((resolve, reject) => {
 		popup(import('@client/components/dialog.vue'), props, {
diff --git a/src/client/pages/settings/index.vue b/src/client/pages/settings/index.vue
index a7ec086bb5..0387d66ae8 100644
--- a/src/client/pages/settings/index.vue
+++ b/src/client/pages/settings/index.vue
@@ -1,40 +1,42 @@
 <template>
 <div class="vvcocwet" :class="{ wide: !narrow }" ref="el">
-	<FormBase class="nav" v-if="!narrow || page == null" :force-wide="!narrow">
-		<FormGroup>
-			<template #label>{{ $ts.basicSettings }}</template>
-			<FormLink :active="page === 'profile'" replace to="/settings/profile"><template #icon><Fa :icon="faUser"/></template>{{ $ts.profile }}</FormLink>
-			<FormLink :active="page === 'privacy'" replace to="/settings/privacy"><template #icon><Fa :icon="faLockOpen"/></template>{{ $ts.privacy }}</FormLink>
-			<FormLink :active="page === 'reaction'" replace to="/settings/reaction"><template #icon><Fa :icon="faLaugh"/></template>{{ $ts.reaction }}</FormLink>
-			<FormLink :active="page === 'drive'" replace to="/settings/drive"><template #icon><Fa :icon="faCloud"/></template>{{ $ts.drive }}</FormLink>
-			<FormLink :active="page === 'notifications'" replace to="/settings/notifications"><template #icon><Fa :icon="faBell"/></template>{{ $ts.notifications }}</FormLink>
-			<FormLink :active="page === 'email'" replace to="/settings/email"><template #icon><Fa :icon="faEnvelope"/></template>{{ $ts.email }}</FormLink>
-			<FormLink :active="page === 'integration'" replace to="/settings/integration"><template #icon><Fa :icon="faShareAlt"/></template>{{ $ts.integration }}</FormLink>
-			<FormLink :active="page === 'security'" replace to="/settings/security"><template #icon><Fa :icon="faLock"/></template>{{ $ts.security }}</FormLink>
-		</FormGroup>
-		<FormGroup>
-			<template #label>{{ $ts.clientSettings }}</template>
-			<FormLink :active="page === 'general'" replace to="/settings/general"><template #icon><Fa :icon="faCogs"/></template>{{ $ts.general }}</FormLink>
-			<FormLink :active="page === 'theme'" replace to="/settings/theme"><template #icon><Fa :icon="faPalette"/></template>{{ $ts.theme }}</FormLink>
-			<FormLink :active="page === 'sidebar'" replace to="/settings/sidebar"><template #icon><Fa :icon="faListUl"/></template>{{ $ts.sidebar }}</FormLink>
-			<FormLink :active="page === 'sounds'" replace to="/settings/sounds"><template #icon><Fa :icon="faMusic"/></template>{{ $ts.sounds }}</FormLink>
-			<FormLink :active="page === 'plugin'" replace to="/settings/plugin"><template #icon><Fa :icon="faPlug"/></template>{{ $ts.plugins }}</FormLink>
-		</FormGroup>
-		<FormGroup>
-			<template #label>{{ $ts.otherSettings }}</template>
-			<FormLink :active="page === 'import-export'" replace to="/settings/import-export"><template #icon><Fa :icon="faBoxes"/></template>{{ $ts.importAndExport }}</FormLink>
-			<FormLink :active="page === 'mute-block'" replace to="/settings/mute-block"><template #icon><Fa :icon="faBan"/></template>{{ $ts.muteAndBlock }}</FormLink>
-			<FormLink :active="page === 'word-mute'" replace to="/settings/word-mute"><template #icon><Fa :icon="faCommentSlash"/></template>{{ $ts.wordMute }}</FormLink>
-			<FormLink :active="page === 'api'" replace to="/settings/api"><template #icon><Fa :icon="faKey"/></template>API</FormLink>
-			<FormLink :active="page === 'other'" replace to="/settings/other"><template #icon><Fa :icon="faEllipsisH"/></template>{{ $ts.other }}</FormLink>
-		</FormGroup>
-		<FormGroup>
-			<FormButton @click="clear">{{ $ts.clearCache }}</FormButton>
-		</FormGroup>
-		<FormGroup>
-			<FormButton @click="logout" danger>{{ $ts.logout }}</FormButton>
-		</FormGroup>
-	</FormBase>
+	<div class="nav" v-if="!narrow || page == null">
+		<FormBase>
+			<FormGroup>
+				<template #label>{{ $ts.basicSettings }}</template>
+				<FormLink :active="page === 'profile'" replace to="/settings/profile"><template #icon><Fa :icon="faUser"/></template>{{ $ts.profile }}</FormLink>
+				<FormLink :active="page === 'privacy'" replace to="/settings/privacy"><template #icon><Fa :icon="faLockOpen"/></template>{{ $ts.privacy }}</FormLink>
+				<FormLink :active="page === 'reaction'" replace to="/settings/reaction"><template #icon><Fa :icon="faLaugh"/></template>{{ $ts.reaction }}</FormLink>
+				<FormLink :active="page === 'drive'" replace to="/settings/drive"><template #icon><Fa :icon="faCloud"/></template>{{ $ts.drive }}</FormLink>
+				<FormLink :active="page === 'notifications'" replace to="/settings/notifications"><template #icon><Fa :icon="faBell"/></template>{{ $ts.notifications }}</FormLink>
+				<FormLink :active="page === 'email'" replace to="/settings/email"><template #icon><Fa :icon="faEnvelope"/></template>{{ $ts.email }}</FormLink>
+				<FormLink :active="page === 'integration'" replace to="/settings/integration"><template #icon><Fa :icon="faShareAlt"/></template>{{ $ts.integration }}</FormLink>
+				<FormLink :active="page === 'security'" replace to="/settings/security"><template #icon><Fa :icon="faLock"/></template>{{ $ts.security }}</FormLink>
+			</FormGroup>
+			<FormGroup>
+				<template #label>{{ $ts.clientSettings }}</template>
+				<FormLink :active="page === 'general'" replace to="/settings/general"><template #icon><Fa :icon="faCogs"/></template>{{ $ts.general }}</FormLink>
+				<FormLink :active="page === 'theme'" replace to="/settings/theme"><template #icon><Fa :icon="faPalette"/></template>{{ $ts.theme }}</FormLink>
+				<FormLink :active="page === 'sidebar'" replace to="/settings/sidebar"><template #icon><Fa :icon="faListUl"/></template>{{ $ts.sidebar }}</FormLink>
+				<FormLink :active="page === 'sounds'" replace to="/settings/sounds"><template #icon><Fa :icon="faMusic"/></template>{{ $ts.sounds }}</FormLink>
+				<FormLink :active="page === 'plugin'" replace to="/settings/plugin"><template #icon><Fa :icon="faPlug"/></template>{{ $ts.plugins }}</FormLink>
+			</FormGroup>
+			<FormGroup>
+				<template #label>{{ $ts.otherSettings }}</template>
+				<FormLink :active="page === 'import-export'" replace to="/settings/import-export"><template #icon><Fa :icon="faBoxes"/></template>{{ $ts.importAndExport }}</FormLink>
+				<FormLink :active="page === 'mute-block'" replace to="/settings/mute-block"><template #icon><Fa :icon="faBan"/></template>{{ $ts.muteAndBlock }}</FormLink>
+				<FormLink :active="page === 'word-mute'" replace to="/settings/word-mute"><template #icon><Fa :icon="faCommentSlash"/></template>{{ $ts.wordMute }}</FormLink>
+				<FormLink :active="page === 'api'" replace to="/settings/api"><template #icon><Fa :icon="faKey"/></template>API</FormLink>
+				<FormLink :active="page === 'other'" replace to="/settings/other"><template #icon><Fa :icon="faEllipsisH"/></template>{{ $ts.other }}</FormLink>
+			</FormGroup>
+			<FormGroup>
+				<FormButton @click="clear">{{ $ts.clearCache }}</FormButton>
+			</FormGroup>
+			<FormGroup>
+				<FormButton @click="logout" danger>{{ $ts.logout }}</FormButton>
+			</FormGroup>
+		</FormBase>
+	</div>
 	<div class="main">
 		<component :is="component" :key="page" @info="onInfo" v-bind="pageProps"/>
 	</div>
@@ -64,7 +66,7 @@ export default defineComponent({
 	},
 
 	props: {
-		page: {
+		initialPage: {
 			type: String,
 			required: false
 		}
@@ -75,6 +77,7 @@ export default defineComponent({
 			title: i18n.locale.settings,
 			icon: faCog
 		});
+		const page = ref(props.initialPage);
 		const narrow = ref(false);
 		const view = ref(null);
 		const el = ref(null);
@@ -83,8 +86,8 @@ export default defineComponent({
 		};
 		const pageProps = ref({});
 		const component = computed(() => {
-			if (props.page == null) return null;
-			switch (props.page) {
+			if (page.value == null) return null;
+			switch (page.value) {
 				case 'profile': return defineAsyncComponent(() => import('./profile.vue'));
 				case 'privacy': return defineAsyncComponent(() => import('./privacy.vue'));
 				case 'reaction': return defineAsyncComponent(() => import('./reaction.vue'));
@@ -117,10 +120,10 @@ export default defineComponent({
 				case 'registry': return defineAsyncComponent(() => import('./registry.vue'));
 				case 'experimental-features': return defineAsyncComponent(() => import('./experimental-features.vue'));
 			}
-			if (props.page.startsWith('registry/keys/system/')) {
+			if (page.value.startsWith('registry/keys/system/')) {
 				return defineAsyncComponent(() => import('./registry.keys.vue'));
 			}
-			if (props.page.startsWith('registry/value/system/')) {
+			if (page.value.startsWith('registry/value/system/')) {
 				return defineAsyncComponent(() => import('./registry.value.vue'));
 			}
 		});
@@ -128,12 +131,12 @@ export default defineComponent({
 		watch(component, () => {
 			pageProps.value = {};
 
-			if (props.page) {
-				if (props.page.startsWith('registry/keys/system/')) {
-					pageProps.value.scope = props.page.replace('registry/keys/system/', '').split('/');
+			if (page.value) {
+				if (page.value.startsWith('registry/keys/system/')) {
+					pageProps.value.scope = page.value.replace('registry/keys/system/', '').split('/');
 				}
-				if (props.page.startsWith('registry/value/system/')) {
-					const path = props.page.replace('registry/value/system/', '').split('/');
+				if (page.value.startsWith('registry/value/system/')) {
+					const path = page.value.replace('registry/value/system/', '').split('/');
 					pageProps.value.xKey = path.pop();
 					pageProps.value.scope = path;
 				}
@@ -144,12 +147,20 @@ export default defineComponent({
 			});
 		}, { immediate: true });
 
+		watch(() => props.initialPage, () => {
+			page.value = props.initialPage;
+		});
+
 		onMounted(() => {
-			narrow.value = el.value.offsetWidth < 1025;
+			narrow.value = el.value.offsetWidth < 800;
+			if (!narrow.value) {
+				page.value = 'profile';
+			}
 		});
 
 		return {
 			[symbols.PAGE_INFO]: INFO,
+			page,
 			narrow,
 			view,
 			el,
@@ -176,25 +187,20 @@ export default defineComponent({
 		display: flex;
 		max-width: 1100px;
 		margin: 0 auto;
+		height: 100%;
 
 		> .nav {
 			width: 32%;
 			box-sizing: border-box;
 			border-right: solid 0.5px var(--divider);
+			overflow: auto;
 		}
 
 		> .main {
 			flex: 1;
 			min-width: 0;
+			overflow: auto;
 			--baseContentWidth: 100%;
-
-			::v-deep(._section) {
-				padding: 0 0 32px 0;
-
-				& + ._section {
-					padding-top: 32px;
-				}
-			}
 		}
 	}
 }
diff --git a/src/client/router.ts b/src/client/router.ts
index 53516db97b..3effb2edbe 100644
--- a/src/client/router.ts
+++ b/src/client/router.ts
@@ -22,7 +22,7 @@ export const router = createRouter({
 		{ path: '/@:user/pages/:page', component: page('page'), props: route => ({ pageName: route.params.page, username: route.params.user }) },
 		{ path: '/@:user/pages/:pageName/view-source', component: page('page-editor/page-editor'), props: route => ({ initUser: route.params.user, initPageName: route.params.pageName }) },
 		{ path: '/@:acct/room', props: true, component: page('room/room') },
-		{ path: '/settings/:page(.*)?', name: 'settings', component: page('settings/index'), props: route => ({ page: route.params.page || null }) },
+		{ path: '/settings/:page(.*)?', name: 'settings', component: page('settings/index'), props: route => ({ initialPage: route.params.page || null }) },
 		{ path: '/announcements', component: page('announcements') },
 		{ path: '/about', component: page('about') },
 		{ path: '/about-misskey', component: page('about-misskey') },
diff --git a/src/client/ui/default.sidebar.vue b/src/client/ui/default.sidebar.vue
index 710a9b1f85..6323393f22 100644
--- a/src/client/ui/default.sidebar.vue
+++ b/src/client/ui/default.sidebar.vue
@@ -27,7 +27,7 @@
 		<Fa :icon="faEllipsisH" fixed-width/><span class="text">{{ $ts.more }}</span>
 		<i v-if="otherNavItemIndicated"><Fa :icon="faCircle"/></i>
 	</button>
-	<MkA class="item" active-class="active" to="/settings">
+	<MkA class="item" active-class="active" to="/settings" :behavior="settingsWindowed ? 'modalWindow' : null">
 		<Fa :icon="faCog" fixed-width/><span class="text">{{ $ts.settings }}</span>
 	</MkA>
 </div>
@@ -57,6 +57,7 @@ export default defineComponent({
 			connection: null,
 			menuDef: sidebarDef,
 			iconOnly: false,
+			settingsWindowed: false,
 			faGripVertical, faChevronLeft, faComments, faHashtag, faBroadcastTower, faFireAlt, faEllipsisH, faPencilAlt, faBars, faTimes, faBell, faSearch, faUserCog, faCog, faUser, faHome, faStar, faCircle, faAt, faEnvelope, faListUl, faPlus, faUserClock, faLaugh, faUsers, faTachometerAlt, faExchangeAlt, faGlobe, faChartBar, faCloud, faServer, faProjectDiagram
 		};
 	},
@@ -102,6 +103,7 @@ export default defineComponent({
 	methods: {
 		calcViewState() {
 			this.iconOnly = (window.innerWidth <= 1400) || (this.$store.state.sidebarDisplay === 'icon');
+			this.settingsWindowed = (window.innerWidth > 1400);
 		},
 
 		post() {