AGENTS.md

@@ -376,6 +376,23 @@ const value =
   short object literals, or short callback bodies that already fit the local
   line-length and delimiter rules. Expanding compact local code without a
   readability need is a minor style violation.
+- In TypeScript and TSX, treat short object literals, short returned objects,
+  short typed object shapes, and short function-call object arguments as
+  compact associative syntax by default. If they fit locally, keep the opening
+  `{` on the same line as the first property and keep the closing `}` on the
+  same line as the final property. Do not explode them into vertical
+  Prettier-style blocks without a concrete readability or line-length reason.
+- In TypeScript and TSX, when a compact associative form is broken across two
+  lines, keep the opening `{` with the first property and the closing `}` with
+  the final property. A shape like `{\n    key: value,\n}` is wrong even when
+  line length would permit it.
+- In TypeScript and TSX, when a short call such as `apiGet<...> (...)`,
+  `apiPatch<...> (...)`, `setState (...)`, `updateClientSettings (...)`, or
+  `window.dispatchEvent (...)` already fits within the local style, do not
+  add extra vertical layers around the object argument or callback body.
+- In TypeScript and TSX, after editing a file, inspect the file tail and
+  remove meaningless blank lines before `export default` or the end of file.
+  A stray empty line before `export default` is a minor style offence.
 - Use correct British English spelling for new identifiers, filenames,
   component names, helper names, comments, and developer-facing prose unless
   editing an already established American-English API that must keep its
@@ -470,6 +487,92 @@ setDirtyStates (
 Penalty: minor offence when semantics stay intact. It is not necessarily
 broken, but it ignores the repository's compact associative style.
 
+#### Prettier-style exploded object literals that should stay compact
+
+Bad:
+
+```ts
+const next = {
+    enabled: keyboard?.enabled !== false,
+    bindings: normaliseKeyboardBindings (keyboard?.bindings),
+}
+```
+
+Good:
+
+```ts
+const next = {
+    enabled: keyboard?.enabled !== false,
+    bindings: normaliseKeyboardBindings (keyboard?.bindings) }
+```
+
+Also good when short enough:
+
+```ts
+const next = { enabled: keyboard?.enabled !== false,
+	       bindings: normaliseKeyboardBindings (keyboard?.bindings) }
+```
+
+Rule: for compact associative syntax, keep `{` with the first property and `}`
+with the final property unless line length truly forces a different shape.
+Do not mechanically apply the common Prettier block form.
+Penalty: medium-severity offence. The code still runs, but it violates a core
+repository formatting habit that must be preserved consistently.
+
+#### Exploded object arguments inside short calls
+
+Bad:
+
+```ts
+updateClientSettings (settings => ({
+    ...settings,
+    keyboard: next,
+}))
+```
+
+Good:
+
+```ts
+updateClientSettings (settings => ({
+    ...settings,
+    keyboard: next }))
+```
+
+Rule: a call-expression closing `)` must not drift onto its own line, and a
+short object argument should not be exploded more than necessary. Keep the
+callback's returned object compact when it fits.
+Penalty: medium-severity offence. This usually means the edit was formatted
+mechanically instead of by reading the local style.
+
+#### Stray blank line before `export default`
+
+Bad:
+
+```ts
+const Component: FC = () => {
+  return <div/>
+}
+
+
+export default Component
+```
+
+Good:
+
+```ts
+const Component: FC = () => {
+  return <div/>
+}
+
+export default Component
+```
+
+Rule: do not leave an extra empty line between the last top-level declaration
+and `export default` unless some surrounding file structure genuinely requires
+visual separation.
+Penalty: minor offence. It is small, but it is easy to avoid and should not
+recur.
+
 ### Frontend delimiter decision table
 
 Use this table before accepting any edited TypeScript or TSX hunk. The table is

frontend/src/lib/settings.ts

@@ -152,8 +152,7 @@ export type ClientSettings = {
     keyboard?:      ClientKeyboardSettings
     panes?:         Record<string, ClientPaneSettings>
     lists?:         Partial<Record<ClientListKey, ClientListSettings>>
-    theatre?:       {
+    theatre?:       { layoutMode?: TheatreLayoutMode
-	layoutMode?: TheatreLayoutMode
 		      tagFlow?:    TheatreTagFlow }
     gekanator?:     { backgroundMotion?: GekanatorBackgroundMotionMode }
     reducedMotion?: string
@@ -273,14 +272,12 @@ export const DARK_THEME_TOKENS: ThemeTokens = {
     topNavMenuLink:              '#93c5fd',
     tagColours:                  DEFAULT_DARK_THEME_TAG_COLOURS }
 export const BUILTIN_THEMES: Record<BuiltinThemeId, ClientTheme> = {
-    light: {
+    light: { id:         'light',
-	id:         'light',
 	     name:       'ライト・モード',
 	     builtin:    true,
 	     baseTheme:  'light',
 	     tokens:     LIGHT_THEME_TOKENS },
-    dark: {
+    dark: { id:         'dark',
-	id:         'dark',
 	    name:       'ダーク・モード',
 	    builtin:    true,
 	    baseTheme:  'dark',
@@ -288,8 +285,7 @@ export const BUILTIN_THEMES: Record<BuiltinThemeId, ClientTheme> = {
 
 const LEGACY_THEATRE_LAYOUT_STORAGE_KEY = 'theatre-layout-mode'
 const LEGACY_THEATRE_TAG_FLOW_STORAGE_KEY = 'theatre-tag-flow'
-const LEGACY_GEKANATOR_BACKGROUND_MOTION_STORAGE_KEY =
+const LEGACY_GEKANATOR_BACKGROUND_MOTION_STORAGE_KEY = 'gekanator:background-motion:v1'
-    'gekanator:background-motion:v1'
 const LEGACY_MIGRATED_THEME_ID = 'custom:legacy-migrated'
 
 
@@ -307,15 +303,13 @@ export const fetchUserSettings = async (): Promise<UserSettings> => {
       theme:                 UserSettings['theme']
       auto_fetch_title:      UserSettings['autoFetchTitle']
       auto_fetch_thumbnail:  UserSettings['autoFetchThumbnail']
-      wiki_editor_mode:      UserSettings['wikiEditorMode']
+      wiki_editor_mode:      UserSettings['wikiEditorMode'] }> ('/users/settings')
-  }> ('/users/settings')
 
   return {
       theme:               raw.theme,
       autoFetchTitle:      raw.auto_fetch_title,
       autoFetchThumbnail:  raw.auto_fetch_thumbnail,
-      wikiEditorMode:      raw.wiki_editor_mode,
+      wikiEditorMode:      raw.wiki_editor_mode }
-  }
 }
 
 
@@ -326,15 +320,13 @@ export const updateUserSettings = async (
       theme:               UserSettings['theme']
       auto_fetch_title:      UserSettings['autoFetchTitle']
       auto_fetch_thumbnail:  UserSettings['autoFetchThumbnail']
-      wiki_editor_mode:      UserSettings['wikiEditorMode']
+      wiki_editor_mode:      UserSettings['wikiEditorMode'] }> ('/users/settings', settings)
-  }> ('/users/settings', settings)
 
   return {
       theme:               raw.theme,
       autoFetchTitle:      raw.auto_fetch_title,
       autoFetchThumbnail:  raw.auto_fetch_thumbnail,
-      wikiEditorMode:      raw.wiki_editor_mode,
+      wikiEditorMode:      raw.wiki_editor_mode }
-  }
 }
 
 
@@ -364,8 +356,7 @@ export const saveClientSettings = (settings: ClientSettings): void => {
   if (typeof window !== 'undefined')
     {
       window.dispatchEvent (new CustomEvent (CLIENT_SETTINGS_EVENT, {
-	  detail: settings,
+	  detail: settings }))
-      }))
     }
 }
 
@@ -428,10 +419,9 @@ const normaliseKeyboardBindings = (
   if (!(bindings) || typeof bindings !== 'object')
     return { }
 
-  return Object.keys (DEFAULT_KEY_BINDINGS).reduce<
+  return (
-      Partial<Record<ShortcutActionId, KeyBinding | null>>
+      Object.keys (DEFAULT_KEY_BINDINGS)
-  > (
+      .reduce<Partial<Record<ShortcutActionId, KeyBinding | null>>> ((normalised, actionId) => {
-      (normalised, actionId) => {
 	const value = (bindings as Record<string, unknown>)[actionId]
 	if (value === null)
 	  {
@@ -444,9 +434,7 @@ const normaliseKeyboardBindings = (
 	  normalised[actionId as ShortcutActionId] = binding
 
 	return normalised
-      },
+      }, { }))
-      { },
-  )
 }
 
 
@@ -455,8 +443,7 @@ export const getClientKeyboardSettings = (): ClientKeyboardSettings => {
 
   return {
       enabled: keyboard?.enabled !== false,
-      bindings: normaliseKeyboardBindings (keyboard?.bindings),
+      bindings: normaliseKeyboardBindings (keyboard?.bindings) }
-  }
 }
 
 
@@ -495,10 +482,7 @@ export const applyClientAnimationMode = (mode: ClientAnimationMode): void => {
 export const setClientAnimationMode = (
     animation: ClientAnimationMode,
 ): ClientBehaviorSettings =>
-    setClientBehaviorSettings ({
+    setClientBehaviorSettings ({ ...getClientBehaviorSettings (), animation })
-	...getClientBehaviorSettings (),
-	animation,
-    })
 
 
 export const getClientLinkPreloadMode = (): ClientLinkPreloadMode =>
@@ -509,10 +493,7 @@ export const getClientLinkPreloadMode = (): ClientLinkPreloadMode =>
 export const setClientLinkPreloadMode = (
     linkPreload: ClientLinkPreloadMode,
 ): ClientBehaviorSettings =>
-    setClientBehaviorSettings ({
+    setClientBehaviorSettings ({ ...getClientBehaviorSettings (), linkPreload })
-	...getClientBehaviorSettings (),
-	linkPreload,
-    })
 
 
 export const getClientTagRelationDisplayMode = (): ClientTagRelationDisplayMode =>
@@ -523,10 +504,7 @@ export const getClientTagRelationDisplayMode = (): ClientTagRelationDisplayMode
 export const setClientTagRelationDisplayMode = (
     tagRelationDisplay: ClientTagRelationDisplayMode,
 ): ClientBehaviorSettings =>
-    setClientBehaviorSettings ({
+    setClientBehaviorSettings ({ ...getClientBehaviorSettings (), tagRelationDisplay })
-	...getClientBehaviorSettings (),
-	tagRelationDisplay,
-    })
 
 
 export const getClientEmbedAutoLoadMode = (): ClientEmbedAutoLoadMode =>
@@ -538,10 +516,7 @@ export const getClientEmbedAutoLoadMode = (): ClientEmbedAutoLoadMode =>
 export const setClientEmbedAutoLoadMode = (
     embedAutoLoad: ClientEmbedAutoLoadMode,
 ): ClientBehaviorSettings =>
-    setClientBehaviorSettings ({
+    setClientBehaviorSettings ({ ...getClientBehaviorSettings (), embedAutoLoad })
-	...getClientBehaviorSettings (),
-	embedAutoLoad,
-    })
 
 
 export const getClientThumbnailMode = (): ClientThumbnailMode =>
@@ -553,10 +528,7 @@ export const getClientThumbnailMode = (): ClientThumbnailMode =>
 export const setClientThumbnailMode = (
     thumbnailMode: ClientThumbnailMode,
 ): ClientBehaviorSettings =>
-    setClientBehaviorSettings ({
+    setClientBehaviorSettings ({ ...getClientBehaviorSettings (), thumbnailMode })
-	...getClientBehaviorSettings (),
-	thumbnailMode,
-    })
 
 
 export const getClientBehaviorSettings = (): ClientBehaviorSettings => ({
@@ -564,8 +536,7 @@ export const getClientBehaviorSettings = (): ClientBehaviorSettings => ({
     linkPreload:      getClientLinkPreloadMode (),
     tagRelationDisplay: getClientTagRelationDisplayMode (),
     embedAutoLoad:    getClientEmbedAutoLoadMode (),
-    thumbnailMode:    getClientThumbnailMode (),
+    thumbnailMode:    getClientThumbnailMode () })
-})
 
 
 export const setClientBehaviorSettings = (
@@ -574,30 +545,21 @@ export const setClientBehaviorSettings = (
   const next: ClientBehaviorSettings = {
       animation: (
 	  normaliseAnimationMode (behavior.animation)
-	  ?? getClientAnimationMode ()
+	  ?? getClientAnimationMode ()),
-      ),
       linkPreload: (
 	  normaliseLinkPreloadMode (behavior.linkPreload)
-	  ?? getClientLinkPreloadMode ()
+	  ?? getClientLinkPreloadMode ()),
-      ),
       tagRelationDisplay: (
 	  normaliseTagRelationDisplayMode (behavior.tagRelationDisplay)
-	  ?? getClientTagRelationDisplayMode ()
+	  ?? getClientTagRelationDisplayMode ()),
-      ),
       embedAutoLoad: (
 	  normaliseEmbedAutoLoadMode (behavior.embedAutoLoad)
-	  ?? getClientEmbedAutoLoadMode ()
+	  ?? getClientEmbedAutoLoadMode ()),
-      ),
       thumbnailMode: (
 	  normaliseThumbnailMode (behavior.thumbnailMode)
-	  ?? getClientThumbnailMode ()
+	  ?? getClientThumbnailMode ()) }
-      ),
-  }
 
-  updateClientSettings (settings => ({
+  updateClientSettings (settings => ({ ...settings, behavior: next }))
-      ...settings,
-      behavior: next,
-  }))
   applyClientAnimationMode (next.animation ?? 'normal')
   return next
 }
@@ -608,13 +570,9 @@ export const setClientKeyboardSettings = (
 ): ClientKeyboardSettings => {
   const next: ClientKeyboardSettings = {
       enabled: keyboard.enabled !== false,
-      bindings: normaliseKeyboardBindings (keyboard.bindings),
+      bindings: normaliseKeyboardBindings (keyboard.bindings) }
-  }
 
-  updateClientSettings (settings => ({
+  updateClientSettings (settings => ({ ...settings, keyboard: next }))
-      ...settings,
-      keyboard: next,
-  }))
 
   return next
 }
@@ -633,8 +591,7 @@ export const getEffectiveKeyBindings = (
 	      : DEFAULT_KEY_BINDINGS[key]
 	  return effectiveBindings
 	},
-	{ ...DEFAULT_KEY_BINDINGS },
+	{ ...DEFAULT_KEY_BINDINGS })
-    )
 
 
 export const setClientKeyBinding = (
@@ -645,11 +602,7 @@ export const setClientKeyBinding = (
 
   return setClientKeyboardSettings ({
       ...current,
-      bindings: {
+      bindings: { ...(current.bindings ?? { }), [actionId]: binding } })
-	  ...(current.bindings ?? { }),
-	  [actionId]: binding,
-      },
-  })
 }
 
 
@@ -660,20 +613,14 @@ export const resetClientKeyBinding = (
   const nextBindings = { ...(current.bindings ?? { }) }
   delete nextBindings[actionId]
 
-  return setClientKeyboardSettings ({
+  return setClientKeyboardSettings ({ ...current, bindings: nextBindings })
-      ...current,
-      bindings: nextBindings,
-  })
 }
 
 
 export const resetAllClientKeyBindings = (): ClientKeyboardSettings => {
   const current = getClientKeyboardSettings ()
 
-  return setClientKeyboardSettings ({
+  return setClientKeyboardSettings ({ ...current, bindings: { } })
-      ...current,
-      bindings: { },
-  })
 }
 
 
@@ -696,21 +643,20 @@ const themeCopyName = (baseTheme: BuiltinThemeId): string =>
 const appearanceFromSettings = (): ClientAppearanceSettings =>
     loadClientSettings ().appearance ?? { }
 
+
 let cachedUserThemeSlots: UserThemeSlotMap = { }
 
 
 export const hasStoredClientThemeSelection = (): boolean => {
   const appearance = appearanceFromSettings ()
-  return (
+  return (appearance.themeMode != null
-      appearance.themeMode != null
 	  || appearance.activeLightThemeSlotNo != null
 	  || appearance.activeDarkThemeSlotNo != null
 	  || appearance.activeThemeSlot != null
 	  || appearance.activeThemeId != null
 	  || appearance.customThemes != null
 	  || appearance.theme != null
-      || appearance.tagColours != null
+	  || appearance.tagColours != null)
-  )
 }
 
 
@@ -725,9 +671,7 @@ const mixHexColour = (
   const channels = [0, 2, 4].map (offset => {
     const srcValue = parseInt (src.slice (offset, offset + 2), 16)
     const dstValue = parseInt (dst.slice (offset, offset + 2), 16)
-      const mixed = Math.round (
+    const mixed = Math.round (srcValue + (dstValue - srcValue) * clampedRatio)
-	  srcValue + (dstValue - srcValue) * clampedRatio,
-      )
     return mixed.toString (16).padStart (2, '0')
   })
 
@@ -749,10 +693,8 @@ const legacyThemeSlotSelection = (): ThemeSlotSelection => {
     return 'builtin:light'
   if (appearance.activeThemeId === 'dark')
     return 'builtin:dark'
-  if (
+  if (typeof appearance.activeThemeId === 'string'
-      typeof appearance.activeThemeId === 'string'
+      && customThemes[appearance.activeThemeId] != null)
-      && customThemes[appearance.activeThemeId] != null
-  )
     return `builtin:${ customThemes[appearance.activeThemeId].baseTheme }`
   if (appearance.theme === 'light')
     return 'builtin:light'
@@ -764,11 +706,9 @@ const legacyThemeSlotSelection = (): ThemeSlotSelection => {
 
 const legacyThemeMode = (): ClientThemeMode =>
     normaliseThemeMode (appearanceFromSettings ().theme)
-    ?? (
+    ?? (legacyThemeSlotSelection () === 'system'
-	legacyThemeSlotSelection () === 'system'
 	? 'system'
-	: (baseThemeOfSelection (legacyThemeSlotSelection ()) ?? 'system')
+	: (baseThemeOfSelection (legacyThemeSlotSelection ()) ?? 'system'))
-    )
 
 
 const legacyThemeSlotNoFor = (
@@ -778,7 +718,7 @@ const legacyThemeSlotNoFor = (
 
   if (isUserThemeSlotSelection (legacySelection))
     {
-      const [_, selectionBaseTheme, slotNo] = legacySelection.split (':')
+      const [, selectionBaseTheme, slotNo] = legacySelection.split (':')
       if (selectionBaseTheme === baseTheme)
 	return Number (slotNo) as UserThemeSlotNo
     }
@@ -798,20 +738,12 @@ export const setClientActiveThemeSlot = (
 ): void => {
   updateClientSettings (settings => ({
       ...settings,
-      appearance: {
+      appearance: { ...(settings.appearance ?? { }), activeThemeSlot } }))
-	  ...(settings.appearance ?? { }),
-	  activeThemeSlot,
-      },
-  }))
 }
 
 
-export const getClientThemeMode = (): UserSettings['theme'] => {
+export const getClientThemeMode = (): UserSettings['theme'] =>
-  return (
+    normaliseThemeMode (appearanceFromSettings ().themeMode) ?? legacyThemeMode ()
-      normaliseThemeMode (appearanceFromSettings ().themeMode)
-      ?? legacyThemeMode ()
-  )
-}
 
 
 export const getClientActiveLightThemeSlotNo = (): UserThemeSlotNo =>
@@ -827,8 +759,7 @@ export const getClientActiveDarkThemeSlotNo = (): UserThemeSlotNo =>
 export const setClientThemeAppearance = (
     { themeMode,
       activeLightThemeSlotNo,
-      activeDarkThemeSlotNo }: {
+      activeDarkThemeSlotNo }: { themeMode:              ClientThemeMode
-	  themeMode:              ClientThemeMode
 				 activeLightThemeSlotNo: UserThemeSlotNo
 				 activeDarkThemeSlotNo:  UserThemeSlotNo },
 ): void => {
@@ -838,9 +769,7 @@ export const setClientThemeAppearance = (
 	  ...(settings.appearance ?? { }),
 	  themeMode,
 	  activeLightThemeSlotNo,
-	  activeDarkThemeSlotNo,
+	  activeDarkThemeSlotNo } }))
-      },
-  }))
 }
 
 
@@ -848,8 +777,7 @@ export const setClientThemeMode = (theme: UserSettings['theme']): void => {
   setClientThemeAppearance ({
       themeMode: theme,
       activeLightThemeSlotNo: getClientActiveLightThemeSlotNo (),
-      activeDarkThemeSlotNo: getClientActiveDarkThemeSlotNo (),
+      activeDarkThemeSlotNo: getClientActiveDarkThemeSlotNo () })
-  })
 }
 
 
@@ -894,8 +822,7 @@ const normaliseThemeTagColours = (
 	      : fallback[category]
 	  return colours
 	},
-	{ ...fallback },
+	{ ...fallback })
-    )
 
 
 const normaliseThemeTokenValue = (
@@ -916,9 +843,9 @@ const cssColourFromThemeToken = (
   if (normalisedHex != null)
     return normalisedHex
 
-  return /^-?\d+(?:\.\d+)?\s+\d+(?:\.\d+)?%\s+\d+(?:\.\d+)?%$/.test (value)
+  return (/^-?\d+(?:\.\d+)?\s+\d+(?:\.\d+)?%\s+\d+(?:\.\d+)?%$/.test (value)
 	  ? `hsl(${ value })`
-      : fallback
+	  : fallback)
 }
 
 
@@ -928,16 +855,12 @@ const clamp = (value: number, min: number, max: number): number =>
 
 const parseHslComponents = (
     value: string,
-): { h: number
+): { h: number; s: number; l: number } | null => {
-      s: number
+  const raw = (value.startsWith ('hsl(') && value.endsWith (')')
-      l: number } | null => {
-  const raw = value.startsWith ('hsl(') && value.endsWith (')')
 	       ? value.slice (4, -1)
-      : value
+	       : value)
   const match =
-      raw.match (
+      raw.match (/^(-?\d+(?:\.\d+)?)\s+(\d+(?:\.\d+)?)%\s+(\d+(?:\.\d+)?)%$/)
-	  /^(-?\d+(?:\.\d+)?)\s+(\d+(?:\.\d+)?)%\s+(\d+(?:\.\d+)?)%$/,
-      )
 
   if (match == null)
     return null
@@ -945,8 +868,7 @@ const parseHslComponents = (
   return {
       h: Number (match[1]),
       s: Number (match[2]),
-      l: Number (match[3]),
+      l: Number (match[3]) }
-  }
 }
 
 
@@ -987,9 +909,7 @@ const deriveMutedForeground = (
       l: clamp (
 	  foregroundHsl.l + (backgroundHsl.l - foregroundHsl.l) * .35,
 	  0,
-	  100,
+	  100) })
-      ),
-  })
 }
 
 
@@ -1006,11 +926,9 @@ const deriveTopNavTokens = (
     mobileActiveBackground: (
 	baseTheme === 'dark'
 	? editable.activeBackground
-	: editable.rootBackgroundDesktop
+	: editable.rootBackgroundDesktop),
-    ),
     brandLink:              editable.brandLink,
-    menuLink:               link,
+    menuLink:               link })
-})
 
 
 export const buildThemeTokens = (
@@ -1047,41 +965,33 @@ export const buildThemeTokens = (
       tokens.topNavRootBackgroundMobile
       ?? legacyTopNavTokens.topNavRootBackgroundMobile
       ?? legacyTopNavTokens.topNavBackground,
-      fallback.topNavRootBackgroundMobile,
+      fallback.topNavRootBackgroundMobile)
-  )
   const topNavRootBackgroundDesktop = normaliseTopNavColourValue (
       tokens.topNavRootBackgroundDesktop
       ?? legacyTopNavTokens.topNavRootBackgroundDesktop
       ?? legacyTopNavTokens.topNavBackground,
-      fallback.topNavRootBackgroundDesktop,
+      fallback.topNavRootBackgroundDesktop)
-  )
   const topNavActiveBackground = normaliseTopNavColourValue (
       tokens.topNavActiveBackground
       ?? legacyTopNavTokens.topNavActiveBackground
       ?? legacyTopNavTokens.topNavHighlightBackground
       ?? legacyTopNavTokens.topNavHighlightBackground,
-      fallback.topNavActiveBackground,
+      fallback.topNavActiveBackground)
-  )
   const topNavBrandLink = normaliseTopNavColourValue (
       tokens.topNavBrandLink
       ?? legacyTopNavTokens.topNavBrandLink
       ?? legacyTopNavTokens.topNavLink,
-      fallback.topNavBrandLink,
+      fallback.topNavBrandLink)
-  )
   const topNavMenuLink = cssColourFromThemeToken (
       link,
-      fallback.topNavMenuLink,
+      fallback.topNavMenuLink)
-  )
   const resolvedTopNav = deriveTopNavTokens (
       baseTheme,
-      {
+      { rootBackgroundMobile: topNavRootBackgroundMobile,
-	  rootBackgroundMobile: topNavRootBackgroundMobile,
 	rootBackgroundDesktop: topNavRootBackgroundDesktop,
 	activeBackground: topNavActiveBackground,
-	  brandLink: topNavBrandLink,
+	brandLink: topNavBrandLink },
-      },
+      topNavMenuLink)
-      topNavMenuLink,
-  )
 
   return {
       background,
@@ -1098,8 +1008,7 @@ export const buildThemeTokens = (
       mutedForeground: deriveMutedForeground (
 	  foreground,
 	  background,
-	  fallback.mutedForeground,
+	  fallback.mutedForeground),
-      ),
       accent,
       accentForeground: readableForegroundFor (accent),
       destructive: fallback.destructive,
@@ -1115,17 +1024,14 @@ export const buildThemeTokens = (
       topNavMobileActiveBackground: resolvedTopNav.mobileActiveBackground,
       topNavBrandLink: resolvedTopNav.brandLink,
       topNavMenuLink: resolvedTopNav.menuLink,
-      tagColours: normaliseThemeTagColours (tokens.tagColours, fallback.tagColours),
+      tagColours: normaliseThemeTagColours (tokens.tagColours, fallback.tagColours) }
-  }
 }
 
 
 const normaliseTopNavColourValue = (
     value:     unknown,
     fallback:  string,
-): string => {
+): string => cssColourFromThemeToken (value, fallback)
-  return cssColourFromThemeToken (value, fallback)
-}
 
 
 const normaliseThemeTokens = (
@@ -1161,8 +1067,7 @@ const normaliseThemeTokens = (
 
   return buildThemeTokens (
       baseTheme,
-      {
+      { ...tokens,
-	  ...tokens,
 	background,
 	foreground,
 	card,
@@ -1191,9 +1096,7 @@ const normaliseThemeTokens = (
 	    tokens.topNavMenuLink
 	    ?? legacyTopNavTokens.topNavMenuLink
 	    ?? link,
-	  tagColours: normaliseThemeTagColours (tokens.tagColours, fallback.tagColours),
+	tagColours: normaliseThemeTagColours (tokens.tagColours, fallback.tagColours) })
-      },
-  )
 }
 
 
@@ -1252,8 +1155,7 @@ export const getDefaultUserThemeSlot = (
 ): UserThemeSlot => ({
     baseTheme,
     slotNo,
-    tokens: normaliseThemeTokens ({ }, baseTheme),
+    tokens: normaliseThemeTokens ({ }, baseTheme) })
-})
 
 
 const normaliseUserThemeSlot = (
@@ -1266,12 +1168,10 @@ const normaliseUserThemeSlot = (
   const baseTheme = slot.baseTheme
   const slotNo = slot.slotNo
 
-  if (
+  if (baseTheme == null
-      baseTheme == null
       || !(isBuiltinThemeId (baseTheme))
       || slotNo == null
-      || !(USER_THEME_SLOT_NOS.includes (slotNo as UserThemeSlotNo))
+      || !(USER_THEME_SLOT_NOS.includes (slotNo as UserThemeSlotNo)))
-  )
     return null
 
   return {
@@ -1279,8 +1179,7 @@ const normaliseUserThemeSlot = (
       slotNo: slotNo as UserThemeSlotNo,
       tokens: normaliseThemeTokens (slot.tokens, baseTheme),
       createdAt: typeof slot.createdAt === 'string' ? slot.createdAt : undefined,
-      updatedAt: typeof slot.updatedAt === 'string' ? slot.updatedAt : undefined,
+      updatedAt: typeof slot.updatedAt === 'string' ? slot.updatedAt : undefined }
-  }
 }
 
 
@@ -1292,8 +1191,7 @@ export const normaliseUserThemeSlots = (
 	  map[getUserThemeSlotSelection (slot.baseTheme, slot.slotNo)] = slot
 	  return map
 	},
-	{ },
+	{ })
-    )
 
 
 const normaliseCustomTheme = (
@@ -1306,13 +1204,11 @@ const normaliseCustomTheme = (
   const id = typeof theme.id === 'string' ? theme.id : null
   const name = typeof theme.name === 'string' ? theme.name : null
   const baseTheme = typeof theme.baseTheme === 'string' ? theme.baseTheme : null
-  if (
+  if (id == null
-      id == null
       || !(isCustomThemeId (id))
       || name == null
       || baseTheme == null
-      || !(isBuiltinThemeId (baseTheme))
+      || !(isBuiltinThemeId (baseTheme)))
-  )
     return null
 
   return {
@@ -1321,21 +1217,16 @@ const normaliseCustomTheme = (
       builtin: false,
       baseTheme,
       tokens: normaliseThemeTokens (
-	  {
+	  { ...(theme.tokens && typeof theme.tokens === 'object'
-	      ...(theme.tokens && typeof theme.tokens === 'object'
 		? theme.tokens as Partial<ThemeTokens>
 		: { }),
 	    tagColours: (
-		  theme.tokens
+		(theme.tokens
 		 && typeof theme.tokens === 'object'
-		  && 'tagColours' in theme.tokens
+		 && 'tagColours' in theme.tokens)
-	      )
 		? (theme.tokens as { tagColours?: Partial<ThemeTagColours> }).tagColours
-		  : theme.tagColours as Partial<ThemeTagColours> | undefined,
+		: theme.tagColours as Partial<ThemeTagColours> | undefined) },
-	  },
+	  baseTheme) }
-	  baseTheme,
-      ),
-  }
 }
 
 
@@ -1352,8 +1243,7 @@ export const getClientCustomThemes = (): Record<string, CustomClientTheme> => {
 	      themes[key] = theme
 	    return themes
 	  },
-	  { },
+	  { })
-      )
     }
 
   const legacyTagColours = appearance.tagColours
@@ -1371,11 +1261,7 @@ export const getClientCustomThemes = (): Record<string, CustomClientTheme> => {
 	      ...(baseTheme === 'dark' ? DARK_THEME_TOKENS : LIGHT_THEME_TOKENS),
 	      tagColours: normaliseThemeTagColours (
 		  legacyTagColours,
-		  defaultThemeTagColoursFor (baseTheme),
+		  defaultThemeTagColoursFor (baseTheme)) } } }
-	      ),
-	  },
-      },
-  }
 }
 
 
@@ -1385,12 +1271,11 @@ export const fetchUserThemeSlots = async (): Promise<UserThemeSlot[]> => {
       slotNo: UserThemeSlotNo
       tokens: ThemeTokens
       createdAt: string
-      updatedAt: string
+      updatedAt: string }>> ('/users/theme_slots')
-  }>> ('/users/theme_slots')
 
-  return raw
+  return (raw
 	  .map (slot => normaliseUserThemeSlot (slot))
-      .filter ((slot): slot is UserThemeSlot => slot != null)
+	  .filter ((slot): slot is UserThemeSlot => slot != null))
 }
 
 
@@ -1404,8 +1289,7 @@ export const upsertUserThemeSlot = async (
       slotNo: UserThemeSlotNo
       tokens: ThemeTokens
       createdAt: string
-      updatedAt: string
+      updatedAt: string }> (`/users/theme_slots/${ baseTheme }/${ slotNo }`, { tokens })
-  }> (`/users/theme_slots/${ baseTheme }/${ slotNo }`, { tokens })
   const slot = normaliseUserThemeSlot (raw)
 
   if (slot == null)
@@ -1427,8 +1311,7 @@ export const getCachedUserThemeSlots = (): UserThemeSlotMap =>
 export const resolveDisplayedTheme = (
     { themeMode,
       activeLightThemeSlotNo,
-      activeDarkThemeSlotNo }: {
+      activeDarkThemeSlotNo }: { themeMode:              ClientThemeMode
-	  themeMode:              ClientThemeMode
 				 activeLightThemeSlotNo: UserThemeSlotNo
 				 activeDarkThemeSlotNo:  UserThemeSlotNo },
     themeSlots: UserThemeSlotMap = getCachedUserThemeSlots (),
@@ -1445,9 +1328,8 @@ export const resolveDisplayedTheme = (
       baseTheme,
       selection,
       slotNo,
-      tokens: themeSlots[selection]?.tokens
+      tokens: (themeSlots[selection]?.tokens
-	  ?? getDefaultUserThemeSlot (baseTheme, slotNo).tokens,
+	       ?? getDefaultUserThemeSlot (baseTheme, slotNo).tokens) }
-  }
 }
 
 
@@ -1464,28 +1346,21 @@ export const getClientActiveThemeId = (): ActiveThemeId => {
   const appearance = appearanceFromSettings ()
   const customThemes = getClientCustomThemes ()
 
-  if (
+  if (typeof appearance.activeThemeId === 'string'
-      typeof appearance.activeThemeId === 'string'
+      && (appearance.activeThemeId === 'system'
-      && (
-	  appearance.activeThemeId === 'system'
 	  || isBuiltinThemeId (appearance.activeThemeId)
-	  || customThemes[appearance.activeThemeId] != null
+	  || customThemes[appearance.activeThemeId] != null))
-      )
-  )
     return appearance.activeThemeId
 
-  if (
+  if (Object.keys (customThemes).length > 0
-      Object.keys (customThemes).length > 0
       && appearance.tagColours != null
-      && Object.keys (appearance.tagColours).length > 0
+      && Object.keys (appearance.tagColours).length > 0)
-  )
     return LEGACY_MIGRATED_THEME_ID
 
-  if (typeof appearance.theme === 'string' && (
+  if (typeof appearance.theme === 'string'
-      appearance.theme === 'system'
+      && (appearance.theme === 'system'
 	  || appearance.theme === 'light'
-      || appearance.theme === 'dark'
+	  || appearance.theme === 'dark'))
-  ))
     return appearance.theme
 
   return DEFAULT_USER_SETTINGS.theme
@@ -1532,8 +1407,7 @@ export const resolveThemeFromSlotSelection = (
 	  selection,
 	  baseTheme,
 	  builtin: true,
-	  tokens: BUILTIN_THEMES[baseTheme].tokens,
+	  tokens: BUILTIN_THEMES[baseTheme].tokens }
-      }
     }
 
   if (isBuiltinThemeSlotSelection (selection))
@@ -1543,8 +1417,7 @@ export const resolveThemeFromSlotSelection = (
 	  selection,
 	  baseTheme,
 	  builtin: true,
-	  tokens: BUILTIN_THEMES[baseTheme].tokens,
+	  tokens: BUILTIN_THEMES[baseTheme].tokens }
-      }
     }
 
   const baseTheme = baseThemeOfSelection (selection) ?? 'light'
@@ -1552,9 +1425,8 @@ export const resolveThemeFromSlotSelection = (
       selection,
       baseTheme,
       builtin: false,
-      tokens: themeSlots[selection]?.tokens
+      tokens: (themeSlots[selection]?.tokens
-	  ?? getDefaultUserThemeSlot (baseTheme, slotNoOfSelection (selection)).tokens,
+	       ?? getDefaultUserThemeSlot (baseTheme, slotNoOfSelection (selection)).tokens) }
-  }
 }
 
 
@@ -1576,21 +1448,15 @@ export const createCustomThemeFromBase = (
       name: themeCopyName (baseTheme),
       builtin: false,
       baseTheme,
-      tokens: tokens ?? {
+      tokens: tokens ?? { ...(baseTheme === 'dark' ? DARK_THEME_TOKENS : LIGHT_THEME_TOKENS) } }
-	  ...(baseTheme === 'dark' ? DARK_THEME_TOKENS : LIGHT_THEME_TOKENS),
-      },
-  }
 }
 
 
 export const getClientThemeTagColours = (
     activeThemeId: ActiveThemeId = getClientActiveThemeId (),
     customThemes:  Record<string, CustomClientTheme> = getClientCustomThemes (),
-): ThemeTagColours => {
+): ThemeTagColours =>
-  return {
+    ({ ...getResolvedThemeFromSelection (activeThemeId, customThemes).tokens.tagColours })
-      ...getResolvedThemeFromSelection (activeThemeId, customThemes).tokens.tagColours,
-  }
-}
 
 
 export const setClientAppearanceThemes = (
@@ -1604,9 +1470,7 @@ export const setClientAppearanceThemes = (
 	  activeThemeId,
 	  customThemes,
 	  theme: undefined,
-	  tagColours: undefined,
+	  tagColours: undefined } }))
-      },
-  }))
 }
 
 
@@ -1620,17 +1484,10 @@ export const setClientThemeTagColours = (
 
   setClientAppearanceThemes (
       activeThemeId,
-      {
+      { ...customThemes,
-	  ...customThemes,
 	[activeThemeId]: {
 	    ...customThemes[activeThemeId],
-	      tokens: {
+	    tokens: { ...customThemes[activeThemeId].tokens, tagColours } } })
-		  ...customThemes[activeThemeId].tokens,
-		  tagColours,
-	      },
-	  },
-      },
-  )
 }
 
 
@@ -1651,8 +1508,7 @@ export const applyThemeTagColours = (tagColours: ThemeTagColours): void => {
     root.style.setProperty (`--tag-colour-${ category }`, colour)
     root.style.setProperty (
 	`--tag-colour-${ category }-hover`,
-	  mixHexColour (colour, '#ffffff', .18),
+	mixHexColour (colour, '#ffffff', .18))
-      )
   })
 }
 
@@ -1680,38 +1536,14 @@ export const applyThemeTokens = (tokens: ThemeTokens): void => {
   root.style.setProperty ('--input', tokens.input)
   root.style.setProperty ('--ring', tokens.ring)
   root.style.setProperty ('--theme-link', tokens.link)
-  root.style.setProperty (
+  root.style.setProperty ('--top-nav-root-bg-mobile', tokens.topNavRootBackgroundMobile)
-      '--top-nav-root-bg-mobile',
+  root.style.setProperty ('--top-nav-root-bg-desktop', tokens.topNavRootBackgroundDesktop)
-      tokens.topNavRootBackgroundMobile,
+  root.style.setProperty ('--top-nav-active-bg', tokens.topNavActiveBackground)
-  )
+  root.style.setProperty ('--top-nav-submenu-bg', tokens.topNavSubmenuBackground)
-  root.style.setProperty (
+  root.style.setProperty ('--top-nav-mobile-menu-bg', tokens.topNavRootBackgroundMobile)
-      '--top-nav-root-bg-desktop',
+  root.style.setProperty ('--top-nav-mobile-active-bg', tokens.topNavMobileActiveBackground)
-      tokens.topNavRootBackgroundDesktop,
+  root.style.setProperty ('--top-nav-brand-link', tokens.topNavBrandLink)
-  )
+  root.style.setProperty ('--top-nav-menu-link', tokens.topNavMenuLink)
-  root.style.setProperty (
-      '--top-nav-active-bg',
-      tokens.topNavActiveBackground,
-  )
-  root.style.setProperty (
-      '--top-nav-submenu-bg',
-      tokens.topNavSubmenuBackground,
-  )
-  root.style.setProperty (
-      '--top-nav-mobile-menu-bg',
-      tokens.topNavRootBackgroundMobile,
-  )
-  root.style.setProperty (
-      '--top-nav-mobile-active-bg',
-      tokens.topNavMobileActiveBackground,
-  )
-  root.style.setProperty (
-      '--top-nav-brand-link',
-      tokens.topNavBrandLink,
-  )
-  root.style.setProperty (
-      '--top-nav-menu-link',
-      tokens.topNavMenuLink,
-  )
 
   applyThemeTagColours (tokens.tagColours)
 }
@@ -1730,17 +1562,14 @@ export const applyThemeSelection = (
 export const applyThemeAppearanceState = (
     { themeMode,
       activeLightThemeSlotNo,
-      activeDarkThemeSlotNo }: {
+      activeDarkThemeSlotNo }: { themeMode:              ClientThemeMode
-	  themeMode:              ClientThemeMode
 				 activeLightThemeSlotNo: UserThemeSlotNo
 				 activeDarkThemeSlotNo:  UserThemeSlotNo },
     themeSlots: UserThemeSlotMap = getCachedUserThemeSlots (),
 ): void => {
-  const theme = resolveDisplayedTheme ({
+  const theme = resolveDisplayedTheme ({ themeMode,
-      themeMode,
 					 activeLightThemeSlotNo,
-      activeDarkThemeSlotNo,
+					 activeDarkThemeSlotNo }, themeSlots)
-  }, themeSlots)
 
   applyThemeMode (theme.baseTheme)
   applyThemeTokens (theme.tokens)
@@ -1753,8 +1582,7 @@ export const applyClientAppearance = (
   applyThemeAppearanceState ({
       themeMode: getClientThemeMode (),
       activeLightThemeSlotNo: getClientActiveLightThemeSlotNo (),
-      activeDarkThemeSlotNo: getClientActiveDarkThemeSlotNo (),
+      activeDarkThemeSlotNo: getClientActiveDarkThemeSlotNo () }, themeSlots)
-  }, themeSlots)
 }
 
 
@@ -1786,20 +1614,17 @@ export const setClientListSettings = (
 	  [listKey]: {
 	      ...(settings.lists?.[listKey] ?? { }),
 	      ...(limit == null ? { } : { limit }),
-	      ...(order == null ? { } : { order }),
+	      ...(order == null ? { } : { order }) } } }))
-	  },
-      },
-  }))
 }
 
 
 const legacyTheatreLayoutMode = (): TheatreLayoutMode | null => {
   const value = localStorage.getItem (LEGACY_THEATRE_LAYOUT_STORAGE_KEY)
-  return (
+  return ((value === 'threeColumns'
-      value === 'threeColumns'
 	   || value === 'tagsBottom'
-      || value === 'commentsBottom'
+	   || value === 'commentsBottom')
-  ) ? value : null
+	  ? value
+	  : null)
 }
 
 
@@ -1841,8 +1666,7 @@ export const setClientTheatreTagFlow = (tagFlow: TheatreTagFlow): void => {
 }
 
 
-export const getClientGekanatorBackgroundMotion =
+export const getClientGekanatorBackgroundMotion = (): GekanatorBackgroundMotionMode =>
-    (): GekanatorBackgroundMotionMode =>
     loadClientSettings ().gekanator?.backgroundMotion
     ?? legacyGekanatorBackgroundMotion ()
     ?? 'on'
@@ -1853,8 +1677,7 @@ export const setClientGekanatorBackgroundMotion = (
 ): void => {
   updateClientSettings (settings => ({
       ...settings,
-      gekanator: { ...(settings.gekanator ?? { }), backgroundMotion },
+      gekanator: { ...(settings.gekanator ?? { }), backgroundMotion } }))
-  }))
 }
 
 
@@ -1880,11 +1703,7 @@ export const setClientPaneWidthPx = (
 	      ...(settings.panes?.[paneKey] ?? { }),
 	      widthPxByBreakpoint: {
 		  ...(settings.panes?.[paneKey]?.widthPxByBreakpoint ?? { }),
-		  [breakpoint]: widthPx,
+		  [breakpoint]: widthPx } } } }))
-	      },
-	  },
-      },
-  }))
 }
 
 
@@ -1898,8 +1717,5 @@ export const setClientPaneCollapsed = (
 	  ...(settings.panes ?? { }),
 	  [paneKey]: {
 	      ...(settings.panes?.[paneKey] ?? { }),
-	      collapsed,
+	      collapsed } } }))
-	  },
-      },
-  }))
 }

frontend/src/pages/users/SettingPage.tsx

@@ -1445,4 +1445,5 @@ const SettingPage: FC<Props> = ({ user, setUser }) => {
       </MainArea>)
 }
 
+
 export default SettingPage