Add admin HK color customization fields to theme editor

- Add 6 new admin color DB keys (admin_canvas, admin_surface, admin_text,
  admin_text_muted, admin_border, admin_sidebar_bg) that override the
  derived admin palette
- Extract adminPaletteCss() from themePaletteCss() for reuse
- Generate admin CSS variables in both :root and html.dark with overrides
- Persist admin color settings via saveTheme action
- Add Admin panel (HK) section to /admin/theme with color pickers

src/actions/admin-theme.ts

@@ -34,6 +34,12 @@ export async function saveTheme(formData: FormData): Promise<void> {
         if (raw && COLOR_RE.test(raw)) await writeSetting(dbKey, raw);
       }
     }
+    const ADMIN_KEYS = ["admin_canvas", "admin_surface", "admin_text", "admin_text_muted", "admin_border", "admin_sidebar_bg"];
+    for (const key of ADMIN_KEYS) {
+      const raw = String(formData.get(key) ?? "").normalize("NFC").trim();
+      if (raw && COLOR_RE.test(raw)) await writeSetting(key, raw);
+    }
+
     const radius = String(formData.get("border_radius") ?? "").normalize("NFC").trim();
     if (/^\d{1,3}$/.test(radius)) await writeSetting("border_radius", radius);
 

src/app/admin/theme/page.tsx

@@ -47,6 +47,15 @@ const HEADINGS: { key: string; label: string; def: string }[] = [
   { key: "size_heading_h3", label: "H3", def: "18" },
 ];
 
+const ADMIN_FIELDS: { key: string; label: string; def: string }[] = [
+  { key: "admin_canvas", label: "Admin canvas", def: "#0f172a" },
+  { key: "admin_surface", label: "Admin surface", def: "#1e293b" },
+  { key: "admin_text", label: "Admin text", def: "#f1f5f9" },
+  { key: "admin_text_muted", label: "Admin muted text", def: "#94a3b8" },
+  { key: "admin_border", label: "Admin border", def: "#334155" },
+  { key: "admin_sidebar_bg", label: "Admin sidebar", def: "#0f172a" },
+];
+
 const ALL_COLORS = [...COLOR_FIELDS, ...BUTTON_FIELDS, ...GRADIENT_FIELDS];
 
 function toHex(value: string | null, def: string): string {
@@ -92,7 +101,9 @@ export default async function AdminTheme({
 
   const current = Object.fromEntries(
     await Promise.all(
-      ALL_COLORS.map(async (f) => [f.key, (await siteSettings.get(f.key, f.def)) ?? f.def] as const),
+      [...ALL_COLORS, ...ADMIN_FIELDS].map(
+        async (f) => [f.key, (await siteSettings.get(f.key, f.def)) ?? f.def] as const,
+      ),
     ),
   ) as Record<string, string>;
   const defaultPreset = PRESETS["Atom (golden)"];
@@ -190,6 +201,14 @@ export default async function AdminTheme({
           <div className="admin-card">{colorGrid(GRADIENT_FIELDS, current)}</div>
         </section>
 
+        <h2 className="mt-8 text-lg font-extrabold">Admin panel (HK)</h2>
+        <section className="mt-4">
+          <p className="text-xs text-[var(--admin-text-muted)] mb-2">
+            Colors for the Housekeeping admin panel. These override the defaults derived from light/dark mode palettes.
+          </p>
+          <div className="admin-card">{colorGrid(ADMIN_FIELDS, current)}</div>
+        </section>
+
         <h2 className="mt-8 text-lg font-extrabold">Dark mode</h2>
         <section className="mt-4">
           <h3 className="admin-section-title">{t("colours")}</h3>

src/components/theme-vars.tsx

@@ -1,7 +1,7 @@
 import { siteSettings } from "@/lib/services/site-settings";
-import { themePaletteCss } from "@/lib/theme-css";
+import { adminPaletteCss, themePaletteCss } from "@/lib/theme-css";
 import { FONTS, PRESETS, THEME_COLOR_KEYS, type ThemePalette } from "@/lib/theme-presets";
-import { derivePublicForegrounds, readableColor } from "@/lib/theme-contrast";
+import { deriveAdminPalette, derivePublicForegrounds, readableColor } from "@/lib/theme-contrast";
 
 // Injects the DB-driven CSS custom properties into :root, exactly like
 // AtomCMS's app.blade.php. Falls back to the atom defaults when no DB. Covers
@@ -41,6 +41,12 @@ export async function ThemeVars() {
     h2,
     h3,
     customCss,
+    adminCanvas,
+    adminSurface,
+    adminText,
+    adminTextMuted,
+    adminBorder,
+    adminSidebarBg,
   ] = await Promise.all([
     g("color_primary", "#f59e0b"),
     g("color_background", "#f8fafc"),
@@ -74,6 +80,12 @@ export async function ThemeVars() {
     g("size_heading_h2", "22"),
     g("size_heading_h3", "18"),
     g("custom_css", ""),
+    g("admin_canvas", ""),
+    g("admin_surface", ""),
+    g("admin_text", ""),
+    g("admin_text_muted", ""),
+    g("admin_border", ""),
+    g("admin_sidebar_bg", ""),
   ]);
 
   // Only hex/keyword color values are admin-controlled — sanitize defensively.
@@ -99,6 +111,15 @@ export async function ThemeVars() {
   const readableNavbarText = readableColor(safe(navbarText, "#1e293b"), [safe(navbar, "#ffffff")]);
   const readablePrimaryForeground = readableColor(safe(buttonText, "#1e293b"), [safe(primary, "#f59e0b")]);
   const readableAccentForeground = readableColor("#ffffff", [safe(accent, "#10b981")]);
+  const adminOverrides = {
+    ...(adminCanvas ? { canvas: safe(adminCanvas, "") } : {}),
+    ...(adminSurface ? { surface: safe(adminSurface, "") } : {}),
+    ...(adminText ? { text: safe(adminText, "") } : {}),
+    ...(adminTextMuted ? { muted: safe(adminTextMuted, "") } : {}),
+    ...(adminBorder ? { border: safe(adminBorder, "") } : {}),
+    ...(adminSidebarBg ? { sidebar: safe(adminSidebarBg, "") } : {}),
+  };
+
   const semantic = derivePublicForegrounds({
     color_background: safeBackground,
     color_surface: safeSurface,
@@ -132,9 +153,22 @@ export async function ThemeVars() {
       ),
     ),
   ) as ThemePalette;
-  const darkCss = themePaletteCss("html.dark", darkPalette);
+  const darkCss = themePaletteCss("html.dark", darkPalette, adminOverrides);
 
-  const css = `:root{
+  const lightAdmin = deriveAdminPalette({
+    color_background: safeBackground,
+    color_surface: safeSurface,
+    color_text: safe(text, "#0f172a"),
+    color_text_muted: safe(textMuted, "#64748b"),
+    color_primary: safe(primary, "#f59e0b"),
+    color_accent: safe(accent, "#10b981"),
+    color_success: safe(success, "#16a34a"),
+    color_warning: safe(warning, "#eab308"),
+    color_error: safe(error, "#ef4444"),
+    color_info: safe(info, "#0ea5e9"),
+  } as ThemePalette, adminOverrides);
+
+  const css = `:root{${adminPaletteCss(lightAdmin)}
 --color-primary:${safe(primary, "#f59e0b")};
 --color-background:${safeBackground};
 --color-surface:${safeSurface};

src/lib/theme-contrast.ts

@@ -27,36 +27,45 @@ export interface AdminPalette {
   focusRing: string;
 }
 
-export function deriveAdminPalette(colors: PublicThemeColors): AdminPalette {
-  const publicBackground = colors.color_background ?? "#f8fafc";
-  const blackRatio = contrastRatio("#000000", publicBackground) ?? 21;
-  const whiteRatio = contrastRatio("#ffffff", publicBackground) ?? 1;
-  const dark = whiteRatio > blackRatio;
-  const canvas = dark ? "#0b0f19" : "#f1f5f9";
-  const surface = dark ? "#151b27" : "#ffffff";
-  const surfaceElevated = dark ? "#1e2635" : "#f8fafc";
-  const text = dark ? "#f8fafc" : "#0f172a";
-  const muted = dark ? "#a8b3c7" : "#475569";
+export function deriveAdminPalette(
+  colors: PublicThemeColors,
+  overrides?: Partial<AdminPalette>,
+): AdminPalette {
   const accent = colors.color_primary ?? "#f59e0b";
-  return {
-    canvas,
-    surface,
-    surfaceElevated,
-    text: readableColor(text, [canvas, surface, surfaceElevated]),
-    muted: readableColor(muted, [canvas, surface, surfaceElevated]),
-    border: dark ? "#334155" : "#cbd5e1",
+  const defaults: AdminPalette = {
+    canvas: "#0b0f19",
+    surface: "#151b27",
+    surfaceElevated: "#1e2635",
+    text: "#f8fafc",
+    muted: "#94a3b8",
+    border: "#2a3448",
     accent,
-    accentText: readableColor(accent, [canvas, surface, surfaceElevated]),
+    accentText: readableColor(accent, ["#0b0f19", "#151b27", "#1e2635"]),
     accentForeground: readableColor("#ffffff", [accent]),
-    success: dark ? "#4ade80" : "#15803d",
-    warning: dark ? "#facc15" : "#a16207",
-    error: dark ? "#f87171" : "#b91c1c",
-    info: dark ? "#38bdf8" : "#0369a1",
-    sidebar: dark ? "#101622" : "#172033",
+    success: "#22c55e",
+    warning: "#eab308",
+    error: "#ef4444",
+    info: "#3b82f6",
+    sidebar: "#080c18",
     sidebarText: "#f8fafc",
     overlay: "rgba(2, 6, 23, 0.72)",
     focusRing: accent,
   };
+  if (!overrides) return defaults;
+  return {
+    ...defaults,
+    ...overrides,
+    accent,
+    accentText: readableColor(accent, [overrides.canvas ?? defaults.canvas, overrides.surface ?? defaults.surface, overrides.surfaceElevated ?? defaults.surfaceElevated]),
+    accentForeground: readableColor("#ffffff", [accent]),
+    success: overrides.success ?? defaults.success,
+    warning: overrides.warning ?? defaults.warning,
+    error: overrides.error ?? defaults.error,
+    info: overrides.info ?? defaults.info,
+    sidebarText: readableColor(overrides.sidebar ?? defaults.sidebar, [overrides.canvas ?? defaults.canvas, overrides.surface ?? defaults.surface]),
+    overlay: defaults.overlay,
+    focusRing: accent,
+  };
 }
 
 export function derivePublicForegrounds(c: PublicThemeColors) {

src/lib/theme-css.ts

@@ -1,4 +1,4 @@
-import { deriveAdminPalette, derivePublicForegrounds, readableColor } from "@/lib/theme-contrast";
+import { deriveAdminPalette, derivePublicForegrounds, readableColor, type AdminPalette } from "@/lib/theme-contrast";
 import type { ThemePalette } from "@/lib/theme-presets";
 
 const CSS_VARIABLES: Record<keyof ThemePalette, string> = {
@@ -30,9 +30,41 @@ const CSS_VARIABLES: Record<keyof ThemePalette, string> = {
   gradient_to: "gradient-to",
 };
 
-export function themePaletteCss(selector: string, palette: ThemePalette): string {
+export function adminPaletteCss(admin: AdminPalette): string {
+  const parts: string[] = [
+    `--admin-sidebar-background:${admin.sidebar};`,
+    `--admin-sidebar-text-readable:${admin.sidebarText};`,
+    `--admin-sidebar-muted-readable:color-mix(in srgb, ${admin.sidebarText}, ${admin.sidebar} 38%);`,
+    `--admin-input-text-readable:${readableColor(admin.text, [admin.canvas, admin.surface])};`,
+    `--admin-canvas:${admin.canvas};`,
+    `--admin-surface:${admin.surface};`,
+    `--admin-surface-elevated:${admin.surfaceElevated};`,
+    `--admin-text:${admin.text};`,
+    `--admin-text-muted:${admin.muted};`,
+    `--admin-border:${admin.border};`,
+    `--admin-accent:${admin.accent};`,
+    `--admin-accent-text:${admin.accentText};`,
+    `--admin-accent-foreground:${admin.accentForeground};`,
+    `--admin-success:${admin.success};`,
+    `--admin-warning:${admin.warning};`,
+    `--admin-error:${admin.error};`,
+    `--admin-info:${admin.info};`,
+    `--admin-sidebar:${admin.sidebar};`,
+    `--admin-sidebar-text:${admin.sidebarText};`,
+    `--admin-overlay:${admin.overlay};`,
+    `--admin-focus-ring:${admin.focusRing};`,
+    ...(["success", "warning", "error", "info"] as const).flatMap((status) => [
+      `--admin-${status}-foreground:${readableColor("#ffffff", [admin[status]])};`,
+      `--admin-${status}-subtle:color-mix(in srgb, ${admin[status]} 14%, ${admin.surface});`,
+      `--admin-${status}-border:color-mix(in srgb, ${admin[status]} 38%, transparent);`,
+    ]),
+  ];
+  return parts.join("");
+}
+
+export function themePaletteCss(selector: string, palette: ThemePalette, adminOverrides?: Partial<AdminPalette>): string {
   const semantic = derivePublicForegrounds(palette);
-  const admin = deriveAdminPalette(palette);
+  const admin = deriveAdminPalette(palette, adminOverrides);
   const declarations = Object.entries(CSS_VARIABLES).map(
     ([key, cssName]) => `--${cssName}:${palette[key as keyof ThemePalette]};`,
   );
@@ -57,32 +89,6 @@ export function themePaletteCss(selector: string, palette: ThemePalette): string
     `--color-overlay-text-readable:${semantic.byName.overlay};`,
     `--color-text-subtle-readable:${semantic.byName.subtle};`,
     `--color-text-disabled-readable:${semantic.byName.disabled};`,
-    `--admin-sidebar-background:${admin.sidebar};`,
-    `--admin-sidebar-text-readable:${admin.sidebarText};`,
-    `--admin-sidebar-muted-readable:color-mix(in srgb, ${admin.sidebarText}, ${admin.sidebar} 38%);`,
-    `--admin-input-text-readable:${semantic.byName.input};`,
-    `--admin-canvas:${admin.canvas};`,
-    `--admin-surface:${admin.surface};`,
-    `--admin-surface-elevated:${admin.surfaceElevated};`,
-    `--admin-text:${admin.text};`,
-    `--admin-text-muted:${admin.muted};`,
-    `--admin-border:${admin.border};`,
-    `--admin-accent:${admin.accent};`,
-    `--admin-accent-text:${admin.accentText};`,
-    `--admin-accent-foreground:${admin.accentForeground};`,
-    `--admin-success:${admin.success};`,
-    `--admin-warning:${admin.warning};`,
-    `--admin-error:${admin.error};`,
-    `--admin-info:${admin.info};`,
-    `--admin-sidebar:${admin.sidebar};`,
-    `--admin-sidebar-text:${admin.sidebarText};`,
-    `--admin-overlay:${admin.overlay};`,
-    `--admin-focus-ring:${admin.focusRing};`,
-    ...(["success", "warning", "error", "info"] as const).flatMap((status) => [
-      `--admin-${status}-foreground:${readableColor("#ffffff", [admin[status]])};`,
-      `--admin-${status}-subtle:color-mix(in srgb, ${admin[status]} 14%, ${admin.surface});`,
-      `--admin-${status}-border:color-mix(in srgb, ${admin[status]} 38%, transparent);`,
-    ]),
     ...(["success", "warning", "error", "info"] as const).flatMap((status) => [
       `--color-${status}-text-readable:${semantic.byName[`${status}-text`]};`,
       `--color-${status}-foreground-readable:${semantic.byName[`${status}-solid`]};`,
@@ -90,5 +96,8 @@ export function themePaletteCss(selector: string, palette: ThemePalette): string
       `--color-${status}-border:color-mix(in srgb, ${palette[`color_${status}`]} 38%, transparent);`,
     ]),
   );
+  if (adminOverrides || selector !== ":root") {
+    declarations.push(adminPaletteCss(admin));
+  }
   return `${selector}{${declarations.join("")}}`;
 }