frontend/src/components/TagSearch.tsx

@@ -105,6 +105,7 @@ const TagSearch: FC = () => {
   return (
       <div className="relative w-full">
 	<input type="text"
+	       data-shortcut-focus-search="true"
 	       placeholder="タグ検索..."
 	       value={search}
 	       onChange={whenChanged}

frontend/src/components/users/KeyboardSettingsSection.tsx

@@ -3,15 +3,18 @@ import { useEffect, useMemo, useState } from 'react'
 import { Button } from '@/components/ui/button'
 import { toast } from '@/components/ui/use-toast'
 import {
+    getConflictingShortcutActionIds,
     formatKeyBinding,
     isSpaceBinding,
     keyBindingFromKeyboardEvent,
     SHORTCUT_DEFINITIONS,
     SHORTCUT_SCOPE_LABELS,
 } from '@/lib/keyboardShortcuts'
+import { getEffectiveKeyBindings } from '@/lib/settings'
 import { useKeyboardShortcutSettings } from '@/lib/useKeyboardShortcuts'
 
 import type { ShortcutActionId } from '@/lib/keyboardShortcuts'
+import type { ClientKeyboardSettings } from '@/lib/settings'
 import type { FC } from 'react'
 
 type Props = {
@@ -21,16 +24,30 @@ type Props = {
 
 const KeyboardSettingsSection: FC<Props> = ({ sectionClassName }) => {
   const {
-    conflictActionIds,
-    effectiveBindings,
       keyboardSettings,
-    resetAllBindings,
+      saveKeyboardSettings,
-    resetBinding,
-    setBinding,
-    setEnabled,
   } = useKeyboardShortcutSettings ()
   const [capturingActionId, setCapturingActionId] =
       useState<ShortcutActionId | null> (null)
+  const [draftKeyboardSettings, setDraftKeyboardSettings] =
+      useState<ClientKeyboardSettings> (keyboardSettings)
+
+  useEffect (() => {
+    setDraftKeyboardSettings (keyboardSettings)
+  }, [keyboardSettings])
+
+  const draftEffectiveBindings = useMemo (
+      () => getEffectiveKeyBindings (draftKeyboardSettings.bindings),
+      [draftKeyboardSettings.bindings],
+  )
+  const draftConflictActionIds = useMemo (
+      () => getConflictingShortcutActionIds (draftEffectiveBindings),
+      [draftEffectiveBindings],
+  )
+  const hasUnsavedChanges = useMemo (
+      () => JSON.stringify (draftKeyboardSettings) !== JSON.stringify (keyboardSettings),
+      [draftKeyboardSettings, keyboardSettings],
+  )
 
   useEffect (() => {
     if (capturingActionId == null)
@@ -51,7 +68,13 @@ const KeyboardSettingsSection: FC<Props> = ({ sectionClassName }) => {
 
       if (event.key === 'Backspace' || event.key === 'Delete')
 	{
-	  setBinding (capturingActionId, null)
+	  setDraftKeyboardSettings (current => ({
+	      ...current,
+	      bindings: {
+		  ...(current.bindings ?? { }),
+		  [capturingActionId]: null,
+	      },
+	  }))
 	  setCapturingActionId (null)
 	  return
 	}
@@ -66,46 +89,92 @@ const KeyboardSettingsSection: FC<Props> = ({ sectionClassName }) => {
 	  return
 	}
 
-      setBinding (capturingActionId, binding)
+      setDraftKeyboardSettings (current => ({
+	  ...current,
+	  bindings: {
+	      ...(current.bindings ?? { }),
+	      [capturingActionId]: binding,
+	  },
+      }))
       setCapturingActionId (null)
     }
 
     document.addEventListener ('keydown', onKeyDown, true)
     return () => document.removeEventListener ('keydown', onKeyDown, true)
-  }, [capturingActionId, setBinding])
+  }, [capturingActionId])
 
   const rows = useMemo (() => SHORTCUT_DEFINITIONS.map (definition => ({
       ...definition,
-      currentBinding:    effectiveBindings[definition.id],
+      currentBinding:    draftEffectiveBindings[definition.id],
-      hasConflict:       conflictActionIds.has (definition.id),
+      hasConflict:       draftConflictActionIds.has (definition.id),
       hasCustomBinding:  Object.prototype.hasOwnProperty.call (
-	  keyboardSettings.bindings ?? { },
+	  draftKeyboardSettings.bindings ?? { },
 	  definition.id,
       ),
-  })), [conflictActionIds, effectiveBindings, keyboardSettings.bindings])
+  })), [
+      draftConflictActionIds,
+      draftEffectiveBindings,
+      draftKeyboardSettings.bindings,
+  ])
+
+  const handleSave = () => {
+    saveKeyboardSettings (draftKeyboardSettings)
+    toast ({ title: 'キーボード設定を保存しました' })
+  }
+
+  const handleDiscard = () => {
+    setDraftKeyboardSettings (keyboardSettings)
+    setCapturingActionId (null)
+  }
 
   return (
       <section className={sectionClassName}>
 	<div className="flex flex-wrap items-start justify-between gap-3">
 	  <div className="space-y-1">
 	    <h2 className="text-xl font-bold">キーボード</h2>
-	    <p className="text-sm text-muted-foreground">
+	    {hasUnsavedChanges && (
-	      この設定は現在のブラウザに自動保存されます．競合した割当は保存されますが，
+		<p className="text-sm text-amber-700 dark:text-amber-300">
-	      dispatcher では発火しません．
+		  未保存の変更があります
-	    </p>
+		</p>)}
 	  </div>
 
-	  <Button type="button" variant="outline" onClick={resetAllBindings}>
+	  <div className="flex flex-wrap gap-2">
+	    <Button
+		type="button"
+		variant="outline"
+		onClick={() => {
+		  setDraftKeyboardSettings (current => ({
+		      ...current,
+		      bindings: { },
+		  }))
+		}}>
 	      すべて既定に戻す
 	    </Button>
+	    <Button
+		type="button"
+		variant="outline"
+		disabled={!(hasUnsavedChanges)}
+		onClick={handleDiscard}>
+	      変更を破棄
+	    </Button>
+	    <Button
+		type="button"
+		disabled={!(hasUnsavedChanges) || draftConflictActionIds.size > 0}
+		onClick={handleSave}>
+	      保存
+	    </Button>
+	  </div>
 	</div>
 
 	<label className="flex items-center gap-2 text-sm">
 	  <input
 	      type="checkbox"
-	      checked={keyboardSettings.enabled !== false}
+	      checked={draftKeyboardSettings.enabled !== false}
 	      onChange={event => {
-		setEnabled (event.target.checked)
+		setDraftKeyboardSettings (current => ({
+		    ...current,
+		    enabled: event.target.checked,
+		}))
 	      }}/>
 	  <span>キーボード・ショートカットを有効にする</span>
 	</label>
@@ -154,7 +223,16 @@ const KeyboardSettingsSection: FC<Props> = ({ sectionClassName }) => {
 			  variant="ghost"
 			  className="h-8"
 			  disabled={!(row.hasCustomBinding)}
-			  onClick={() => resetBinding (row.id)}>
+			  onClick={() => {
+			    setDraftKeyboardSettings (current => {
+				const nextBindings = { ...(current.bindings ?? { }) }
+				delete nextBindings[row.id]
+				return {
+				    ...current,
+				    bindings: nextBindings,
+				}
+			    })
+			  }}>
 			既定に戻す
 		      </Button>
 		    </td>

frontend/src/components/users/ShortcutHelpDialog.tsx

@@ -0,0 +1,77 @@
+import {
+    Dialog,
+    DialogContent,
+    DialogDescription,
+    DialogHeader,
+    DialogTitle,
+} from '@/components/ui/dialog'
+import {
+    formatKeyBinding,
+    SHORTCUT_DEFINITIONS,
+    SHORTCUT_SCOPE_LABELS,
+} from '@/lib/keyboardShortcuts'
+
+import type {
+    KeyBinding,
+    ShortcutActionId,
+    ShortcutScope,
+} from '@/lib/keyboardShortcuts'
+import type { FC } from 'react'
+
+type Props = {
+    open:               boolean
+    onOpenChange:       (open: boolean) => void
+    activeScope:        ShortcutScope
+    effectiveBindings:  Record<ShortcutActionId, KeyBinding | null>
+    conflictActionIds:  Set<ShortcutActionId>
+}
+
+
+const ShortcutHelpDialog: FC<Props> = (
+    { open, onOpenChange, activeScope, effectiveBindings, conflictActionIds },
+) => {
+  const rows = SHORTCUT_DEFINITIONS.filter (definition =>
+      definition.scope === 'global' || definition.scope === activeScope)
+
+  return (
+      <Dialog open={open} onOpenChange={onOpenChange}>
+	<DialogContent className="max-w-3xl px-6 pb-6 pt-7">
+	  <DialogHeader className="pl-8">
+	    <DialogTitle>キーボード・ショートカット</DialogTitle>
+	    <DialogDescription>
+	      この画面で利用できるショートカットを表示します。
+	    </DialogDescription>
+	  </DialogHeader>
+
+	  <div className="overflow-x-auto">
+	    <table className="w-full min-w-[40rem] table-fixed border-collapse text-sm">
+	      <thead className="border-b border-border">
+		<tr>
+		  <th className="p-2 text-left">操作</th>
+		  <th className="p-2 text-left">適用範囲</th>
+		  <th className="p-2 text-left">キー</th>
+		  <th className="p-2 text-left">競合</th>
+		</tr>
+	      </thead>
+	      <tbody>
+		{rows.map (row => (
+		    <tr key={row.id} className="border-b border-border/60 last:border-b-0">
+		      <td className="p-2">{row.label}</td>
+		      <td className="p-2">{SHORTCUT_SCOPE_LABELS[row.scope]}</td>
+		      <td className="p-2 font-mono">
+			{formatKeyBinding (effectiveBindings[row.id])}
+		      </td>
+		      <td className="p-2">
+			{conflictActionIds.has (row.id)
+			 ? <span className="text-red-600 dark:text-red-400">競合あり</span>
+			 : 'なし'}
+		      </td>
+		    </tr>))}
+	      </tbody>
+	    </table>
+	  </div>
+	</DialogContent>
+      </Dialog>)
+}
+
+export default ShortcutHelpDialog

frontend/src/lib/useKeyboardShortcuts.tsx

@@ -9,10 +9,9 @@ import {
 } from 'react'
 import { useLocation, useNavigate } from 'react-router-dom'
 
-import { toast } from '@/components/ui/use-toast'
+import ShortcutHelpDialog from '@/components/users/ShortcutHelpDialog'
 import {
     DEFAULT_KEY_BINDINGS,
-    formatKeyBinding,
     getConflictingShortcutActionIds,
     isEditableEventTarget,
     keyBindingFromKeyboardEvent,
@@ -46,6 +45,7 @@ type KeyboardShortcutsContextValue = {
     keyboardSettings:   ClientKeyboardSettings
     effectiveBindings:  Record<ShortcutActionId, KeyBinding | null>
     conflictActionIds:  Set<ShortcutActionId>
+    saveKeyboardSettings: (settings: ClientKeyboardSettings) => void
     setEnabled:         (enabled: boolean) => void
     setBinding:         (actionId: ShortcutActionId, binding: KeyBinding | null) => void
     resetBinding:       (actionId: ShortcutActionId) => void
@@ -57,17 +57,47 @@ const KeyboardShortcutsContext =
     createContext<KeyboardShortcutsContextValue | null> (null)
 
 
-const buildShortcutHelpText = (
+const isFocusableShortcutTarget = (element: HTMLElement): boolean => {
-    activeScope:        ShortcutScope,
+  if (element.closest ('[hidden], [aria-hidden="true"]') != null)
-    effectiveBindings:  Record<ShortcutActionId, KeyBinding | null>,
+    return false
-): string =>
+
-    SHORTCUT_DEFINITIONS
+  if (
-	.filter (definition =>
+      (element instanceof HTMLInputElement
-	    definition.scope === 'global' || definition.scope === activeScope)
+       || element instanceof HTMLButtonElement
-	.filter (definition => effectiveBindings[definition.id] != null)
+       || element instanceof HTMLSelectElement
-	.map (definition =>
+       || element instanceof HTMLTextAreaElement)
-	    `${ definition.label }: ${ formatKeyBinding (effectiveBindings[definition.id]) }`)
+      && element.disabled
-	.join (' / ')
+  )
+    return false
+
+  const style = window.getComputedStyle (element)
+  if (
+      style.display === 'none'
+      || style.visibility === 'hidden'
+      || style.pointerEvents === 'none'
+  )
+    return false
+
+  return element.getClientRects ().length > 0
+}
+
+
+const focusSearchTarget = (): void => {
+  const targets = [
+      ...document.querySelectorAll<HTMLElement> (
+	  '[data-shortcut-focus-search="true"]',
+      ),
+  ]
+  const target = targets.find (isFocusableShortcutTarget)
+
+  if (target == null)
+    return
+
+  target.focus ()
+
+  if (target instanceof HTMLInputElement || target instanceof HTMLTextAreaElement)
+    target.select ()
+}
 
 
 export const KeyboardShortcutsProvider = ({ children }: PropsWithChildren) => {
@@ -78,6 +108,7 @@ export const KeyboardShortcutsProvider = ({ children }: PropsWithChildren) => {
       useState<ClientKeyboardSettings> (() => getClientKeyboardSettings ())
   const [registeredHandlers, setRegisteredHandlers] =
       useState<Record<number, ShortcutHandlers>> ({ })
+  const [shortcutHelpOpen, setShortcutHelpOpen] = useState (false)
   const registrationIdRef = useRef (0)
 
   const activeScope = useMemo<ShortcutScope> (
@@ -108,6 +139,11 @@ export const KeyboardShortcutsProvider = ({ children }: PropsWithChildren) => {
     setKeyboardSettingsState (next)
   }, [keyboardSettings])
 
+  const saveKeyboardSettings = useCallback ((settings: ClientKeyboardSettings) => {
+    const next = setClientKeyboardSettings (settings)
+    setKeyboardSettingsState (next)
+  }, [])
+
   const setBinding = useCallback ((
       actionId: ShortcutActionId,
       binding:  KeyBinding | null,
@@ -157,6 +193,9 @@ export const KeyboardShortcutsProvider = ({ children }: PropsWithChildren) => {
       if (isEditableEventTarget (event.target))
 	return
 
+      if (shortcutHelpOpen)
+	return
+
       const binding = keyBindingFromKeyboardEvent (event)
       if (binding == null)
 	return
@@ -183,21 +222,10 @@ export const KeyboardShortcutsProvider = ({ children }: PropsWithChildren) => {
       const builtinHandler = (
 	  {
 	      'global.openShortcutHelp': () => {
-		  const description =
+		  setShortcutHelpOpen (true)
-		      buildShortcutHelpText (activeScope, effectiveBindings)
-		      || 'この画面で使えるショートカットはありません．'
-		  toast ({
-		      title: 'キーボード・ショートカット',
-		      description,
-		  })
 	      },
 	      'global.focusSearch': () => {
-		  const target = document.querySelector<HTMLElement> (
+		  focusSearchTarget ()
-		      '[data-shortcut-focus-search="true"]',
-		  )
-		  target?.focus ()
-		  if (target instanceof HTMLInputElement || target instanceof HTMLTextAreaElement)
-		    target.select ()
 	      },
 	      'navigation.posts': () => navigate ('/posts'),
 	      'navigation.tags': () => navigate ('/tags'),
@@ -226,6 +254,7 @@ export const KeyboardShortcutsProvider = ({ children }: PropsWithChildren) => {
       keyboardSettings.enabled,
       mergedRegisteredHandlers,
       navigate,
+      shortcutHelpOpen,
   ])
 
   const value = useMemo<KeyboardShortcutsContextValue> (() => ({
@@ -234,6 +263,7 @@ export const KeyboardShortcutsProvider = ({ children }: PropsWithChildren) => {
       effectiveBindings,
       conflictActionIds,
       setEnabled,
+      saveKeyboardSettings,
       setBinding,
       resetBinding,
       resetAllBindings,
@@ -246,6 +276,7 @@ export const KeyboardShortcutsProvider = ({ children }: PropsWithChildren) => {
       registerHandlers,
       resetAllBindings,
       resetBinding,
+      saveKeyboardSettings,
       setBinding,
       setEnabled,
   ])
@@ -253,6 +284,12 @@ export const KeyboardShortcutsProvider = ({ children }: PropsWithChildren) => {
   return (
       <KeyboardShortcutsContext.Provider value={value}>
 	{children}
+	<ShortcutHelpDialog
+	    open={shortcutHelpOpen}
+	    onOpenChange={setShortcutHelpOpen}
+	    activeScope={activeScope}
+	    effectiveBindings={effectiveBindings}
+	    conflictActionIds={conflictActionIds}/>
       </KeyboardShortcutsContext.Provider>)
 }
 

frontend/src/pages/users/SettingPage.tsx

@@ -254,28 +254,10 @@ const ThemeSection: FC<SharedSectionProps> = (
 	    </select>)}
       </FormField>
 
-      <div className="space-y-2 rounded-lg border border-dashed border-border/70 p-3 text-sm">
-	<p>
-	  テーマの選択状態は現在のブラウザに保存し，背景・文字色はそのテーマの base に従います．
-	</p>
-	<p className="text-muted-foreground">
-	  backend には system / light / dark の mode だけ保存します．
-	  カスタムテーマ本体は今は browser-local です．
-	</p>
-	<p className="text-muted-foreground">
-	  将来は themes テーブルなどへ移して，端末間同期できる構造に拡張できます．
-	</p>
-      </div>
-
       <div className="space-y-3">
 	<div className="flex flex-wrap items-center justify-between gap-2">
 	  <div>
 	  <h3 className="font-medium">タグカテゴリ色</h3>
-	  <p className="text-sm text-muted-foreground">
-	    {selectedTheme.builtin || draftActiveThemeId === 'system'
-	     ? '組み込みテーマは直接変更されません．色を変更するとカスタムテーマを作成します．'
-	     : `現在の編輯対象: ${ selectedTheme.name }`}
-	  </p>
 	  </div>
 	  <Button
 	      type="button"
@@ -344,14 +326,6 @@ const ThemeSection: FC<SharedSectionProps> = (
 	</div>
       </div>
 
-      <div className="space-y-2 rounded-lg border border-dashed border-border/70 p-3 text-sm">
-	<p className="font-medium">既存 backend 設定について</p>
-	<p>
-	  auto_fetch_title、auto_fetch_thumbnail、wiki_editor_mode は backend 側に
-	  保持したままです．この共通設定画面にはまだ接続していません．
-	</p>
-      </div>
-
       <Button type="button" onClick={onThemeSubmit}>
 	テーマを保存
       </Button>
@@ -682,15 +656,40 @@ const SettingPage: FC<Props> = ({ user, setUser }) => {
 	<div className="mx-auto max-w-xl space-y-4 p-4 md:hidden">
 	  <PageTitle>設定</PageTitle>
 	  <FieldError messages={settingsError ? [settingsError] : []}/>
+	  <div
+	      role="tablist"
+	      aria-label="設定区分"
+	      aria-orientation="horizontal"
+	      className="-mx-4 flex gap-2 overflow-x-auto px-4 pb-1">
+	    {tabs.map (tab => (
+		<button
+		    key={tab.id}
+		    id={tabButtonId (tab.id)}
+		    type="button"
+		    role="tab"
+		    aria-selected={activeTab === tab.id}
+		    aria-controls={tabPanelId (tab.id)}
+		    className={cn (
+			'shrink-0 rounded-full border px-3 py-2 text-sm font-medium',
+			(activeTab === tab.id
+			 ? ['border-slate-900 bg-slate-900 text-white',
+			    'dark:border-slate-100 dark:bg-slate-100 dark:text-slate-900']
+			 : ['border-border bg-background text-foreground']))}
+		    onClick={() => setActiveTab (tab.id)}>
+		  {tab.label}
+		  {settingsTabErrors[tab.id] ? ' !' : ''}
+		</button>))}
+	  </div>
 	  {loading ? 'Loading...' : (
-	      <>
+	      <div
-		{sectionProps && (
+		  id={tabPanelId (activeTab)}
-		    <>
+		  role="tabpanel"
-		      <AccountSection {...sectionProps}/>
+		  aria-labelledby={tabButtonId (activeTab)}>
-		      <ThemeSection {...sectionProps}/>
+		{sectionProps && activeTab === 'account' && <AccountSection {...sectionProps}/>}
-		      <KeyboardSettingsSection sectionClassName={sectionClassName}/>
+		{sectionProps && activeTab === 'theme' && <ThemeSection {...sectionProps}/>}
-		    </>)}
+		{activeTab === 'keyboard' && (
-	      </>)}
+		    <KeyboardSettingsSection sectionClassName={sectionClassName}/>)}
+	      </div>)}
 	</div>
 
 	<div className="hidden md:flex md:justify-center md:px-4">