Add Theme Settings tool + polish remaining radio detail pages

- New /admin/theme: recolour the whole site from housekeeping. 6 atom-
  faithful presets (Atom/Midnight/Ocean/Forest/Sunset/Candy) + per-colour
  pickers for the 12 settings ThemeVars injects + border radius. Writes to
  website_settings, busts the siteSettings cache, and revalidates the
  layout so the new palette applies live with no rebuild. Constants live
  in src/lib/theme-presets.ts (a "use server" file can't export objects).
  Added to the admin sidebar (System).
- radio/contests/[id] + giveaways/[id] wrapped in ContentCard to match
  the public design system.
- Skipped a separate VPN page: /admin/ip already manages the IP
  white/blacklist, so it would only duplicate it.

Verified live (prod, amx_test): applied the Ocean preset → home renders
--color-primary #0ea5e9 site-wide; reverted the test rows. tsc 0,
vitest 49/49, next build 0.

src/actions/admin-theme.ts

@@ -0,0 +1,65 @@
+"use server";
+
+import { revalidatePath } from "next/cache";
+import { redirect } from "next/navigation";
+import { requireStaff } from "@/lib/admin/guard";
+import { prisma } from "@/lib/prisma";
+import { siteSettings } from "@/lib/services/site-settings";
+import { logStaffActivity } from "@/lib/services/staff-activity";
+import { PRESETS, THEME_COLOR_KEYS } from "@/lib/theme-presets";
+
+// Only hex/keyword colour values are accepted (matches ThemeVars' sanitiser).
+const COLOR_RE = /^[#a-zA-Z0-9(),.\s%-]+$/;
+
+async function writeSetting(key: string, value: string): Promise<void> {
+  await prisma.websiteSetting.upsert({
+    where: { key },
+    update: { value },
+    create: { key, value, comment: "Theme (housekeeping)" },
+  });
+}
+
+export async function saveTheme(formData: FormData): Promise<void> {
+  const staff = await requireStaff();
+
+  try {
+    for (const key of THEME_COLOR_KEYS) {
+      const raw = String(formData.get(key) ?? "").trim();
+      if (raw && COLOR_RE.test(raw)) await writeSetting(key, raw);
+    }
+    const radius = String(formData.get("border_radius") ?? "").trim();
+    if (/^\d{1,3}$/.test(radius)) await writeSetting("border_radius", radius);
+
+    siteSettings.reload();
+    await logStaffActivity({
+      staffId: staff.id,
+      action: "theme_update",
+      description: "Updated theme colours",
+    });
+    revalidatePath("/", "layout");
+  } catch {
+    // ignore — page re-renders current state
+  }
+  redirect("/admin/theme?saved=1");
+}
+
+export async function applyPreset(formData: FormData): Promise<void> {
+  const staff = await requireStaff();
+  const name = String(formData.get("preset") ?? "");
+  const preset = PRESETS[name];
+  if (!preset) redirect("/admin/theme");
+
+  try {
+    for (const [key, value] of Object.entries(preset)) await writeSetting(key, value);
+    siteSettings.reload();
+    await logStaffActivity({
+      staffId: staff.id,
+      action: "theme_preset",
+      description: `Applied theme preset "${name}"`,
+    });
+    revalidatePath("/", "layout");
+  } catch {
+    // ignore
+  }
+  redirect(`/admin/theme?preset=${encodeURIComponent(name)}`);
+}

src/app/admin/layout.tsx

@@ -69,6 +69,7 @@ const NAV_GROUPS: { label: string; items: { href: string; label: string }[] }[]
       { href: "/admin/housekeeping", label: "Housekeeping" },
       { href: "/admin/rooms", label: "Rooms" },
       { href: "/admin/email-templates", label: "Email" },
+      { href: "/admin/theme", label: "Theme" },
       { href: "/admin/settings", label: "Settings" },
     ],
   },

src/app/admin/theme/page.tsx

@@ -0,0 +1,138 @@
+import { applyPreset, saveTheme } from "@/actions/admin-theme";
+import { siteSettings } from "@/lib/services/site-settings";
+import { PRESETS } from "@/lib/theme-presets";
+
+export const dynamic = "force-dynamic";
+export const metadata = { title: "Theme" };
+
+const FIELDS: { key: string; label: string; def: string }[] = [
+  { key: "color_primary", label: "Primary", def: "#f59e0b" },
+  { key: "color_accent", label: "Accent", def: "#10b981" },
+  { key: "border_color", label: "Border (golden)", def: "#eeb425" },
+  { key: "color_background", label: "Background", def: "#f8fafc" },
+  { key: "color_surface", label: "Surface / cards", def: "#ffffff" },
+  { key: "color_dropdown", label: "Dropdown", def: "#ffffff" },
+  { key: "color_navbar", label: "Navbar", def: "#ffffff" },
+  { key: "color_navbar_text", label: "Navbar text", def: "#1e293b" },
+  { key: "color_text", label: "Text", def: "#0f172a" },
+  { key: "color_text_muted", label: "Muted text", def: "#64748b" },
+  { key: "button_primary_color", label: "Button", def: "#f59e0b" },
+  { key: "button_text_color", label: "Button text", def: "#1e293b" },
+];
+
+/** A <input type=color> needs #rrggbb — fall back to the default otherwise. */
+function toHex(value: string | null, def: string): string {
+  return value && /^#[0-9a-fA-F]{6}$/.test(value) ? value : def;
+}
+
+export default async function AdminTheme({
+  searchParams,
+}: {
+  searchParams: Promise<{ saved?: string; preset?: string }>;
+}) {
+  const sp = await searchParams;
+
+  const current = Object.fromEntries(
+    await Promise.all(
+      FIELDS.map(async (f) => [f.key, (await siteSettings.get(f.key, f.def)) ?? f.def] as const),
+    ),
+  ) as Record<string, string>;
+  const radius = (await siteSettings.get("border_radius", "12")) ?? "12";
+
+  return (
+    <main>
+      <h1>Theme</h1>
+      <p className="muted" style={{ marginTop: "-0.4rem" }}>
+        Recolour the whole site. Values are written to <code>website_settings</code> and applied
+        live (no rebuild).
+      </p>
+
+      {sp.saved ? (
+        <p className="admin-badge ok" style={{ display: "inline-block" }}>
+          Theme saved
+        </p>
+      ) : null}
+      {sp.preset ? (
+        <p className="admin-badge ok" style={{ display: "inline-block" }}>
+          Applied preset “{sp.preset}”
+        </p>
+      ) : null}
+
+      <section className="admin-section">
+        <h2>Presets</h2>
+        <div style={{ display: "flex", flexWrap: "wrap", gap: "0.5rem" }}>
+          {Object.entries(PRESETS).map(([name, palette]) => (
+            <form key={name} action={applyPreset}>
+              <input type="hidden" name="preset" value={name} />
+              <button
+                type="submit"
+                className="btn btn-outline"
+                style={{ display: "inline-flex", alignItems: "center", gap: "0.5rem" }}
+              >
+                <span style={{ display: "inline-flex" }}>
+                  {["color_primary", "color_accent", "color_surface", "color_text"].map((k) => (
+                    <span
+                      key={k}
+                      style={{
+                        width: 14,
+                        height: 14,
+                        borderRadius: 3,
+                        background: palette[k],
+                        boxShadow: "inset 0 0 0 1px rgba(0,0,0,0.15)",
+                        marginLeft: -3,
+                      }}
+                    />
+                  ))}
+                </span>
+                {name}
+              </button>
+            </form>
+          ))}
+        </div>
+      </section>
+
+      <section className="admin-section">
+        <h2>Custom colours</h2>
+        <form action={saveTheme} className="card">
+          <div
+            style={{
+              display: "grid",
+              gridTemplateColumns: "repeat(auto-fit, minmax(190px, 1fr))",
+              gap: "0.75rem 1.25rem",
+            }}
+          >
+            {FIELDS.map((f) => (
+              <label
+                key={f.key}
+                style={{ display: "flex", alignItems: "center", gap: "0.6rem" }}
+              >
+                <input
+                  type="color"
+                  name={f.key}
+                  defaultValue={toHex(current[f.key], f.def)}
+                  style={{ width: 40, height: 30, padding: 0, border: "none", background: "none" }}
+                />
+                <span style={{ fontSize: "0.88rem" }}>{f.label}</span>
+              </label>
+            ))}
+          </div>
+
+          <div style={{ marginTop: "1rem", display: "flex", alignItems: "center", gap: "0.6rem" }}>
+            <label style={{ fontSize: "0.88rem" }}>Border radius (px)</label>
+            <input
+              name="border_radius"
+              type="number"
+              min={0}
+              max={40}
+              defaultValue={/^\d{1,3}$/.test(radius) ? radius : "12"}
+              style={{ width: 90 }}
+            />
+            <button type="submit" className="btn btn-primary" style={{ marginLeft: "auto" }}>
+              Save theme
+            </button>
+          </div>
+        </form>
+      </section>
+    </main>
+  );
+}

src/app/radio/contests/[id]/page.tsx

@@ -1,5 +1,6 @@
 import Link from "next/link";
 import { notFound } from "next/navigation";
+import { ContentCard } from "@/components/public/ui";
 import { prisma } from "@/lib/prisma";
 
 export const dynamic = "force-dynamic";
@@ -33,13 +34,12 @@ export default async function RadioContestDetailPage({
   const contestIdStr = contest.id.toString();
 
   return (
-    <main>
+    <main style={{ display: "grid", gap: "1.5rem" }}>
-      <p className="muted" style={{ margin: "0 0 0.5rem" }}>
+      <p className="muted" style={{ margin: 0 }}>
         <Link href="/radio/contests">← Back to contests</Link>
       </p>
 
-      <div className="card">
+      <ContentCard icon="🎉" title={`Contest #${contestIdStr}`} subtitle="Radio contest details">
-        <h1 style={{ margin: "0 0 0.5rem" }}>Contest #{contestIdStr}</h1>
         <table>
           <tbody>
             <tr>
@@ -52,7 +52,7 @@ export default async function RadioContestDetailPage({
             </tr>
           </tbody>
         </table>
-      </div>
+      </ContentCard>
     </main>
   );
 }

src/app/radio/giveaways/[id]/page.tsx

@@ -1,5 +1,6 @@
 import Link from "next/link";
 import { notFound } from "next/navigation";
+import { ContentCard } from "@/components/public/ui";
 import { prisma } from "@/lib/prisma";
 
 export const dynamic = "force-dynamic";
@@ -33,13 +34,12 @@ export default async function RadioGiveawayDetailPage({
   const giveawayIdStr = giveaway.id.toString();
 
   return (
-    <main>
+    <main style={{ display: "grid", gap: "1.5rem" }}>
-      <p className="muted" style={{ margin: "0 0 0.5rem" }}>
+      <p className="muted" style={{ margin: 0 }}>
         <Link href="/radio/giveaways">← Back to giveaways</Link>
       </p>
 
-      <div className="card">
+      <ContentCard icon="🎁" title={`Giveaway #${giveawayIdStr}`} subtitle="Radio giveaway details">
-        <h1 style={{ margin: "0 0 0.5rem" }}>Giveaway #{giveawayIdStr}</h1>
         <table>
           <tbody>
             <tr>
@@ -52,7 +52,7 @@ export default async function RadioGiveawayDetailPage({
             </tr>
           </tbody>
         </table>
-      </div>
+      </ContentCard>
     </main>
   );
 }

src/lib/theme-presets.ts

@@ -0,0 +1,108 @@
+// Theme constants shared by the admin Theme page and its server action. Kept in
+// a plain module because a "use server" file may only export async functions.
+
+// The colour settings ThemeVars injects into :root. Editing these recolours the
+// whole site live (ThemeVars reads them on every request).
+export const THEME_COLOR_KEYS = [
+  "color_primary",
+  "color_background",
+  "color_surface",
+  "color_dropdown",
+  "color_navbar",
+  "color_navbar_text",
+  "color_text",
+  "color_text_muted",
+  "color_accent",
+  "button_primary_color",
+  "button_text_color",
+  "border_color",
+] as const;
+
+// Curated palettes (faithful to the atom theme presets). Each is a full set of
+// the colour keys above so applying one fully reskins the site.
+export const PRESETS: Record<string, Record<string, string>> = {
+  "Atom (golden)": {
+    color_primary: "#f59e0b",
+    color_background: "#f8fafc",
+    color_surface: "#ffffff",
+    color_dropdown: "#ffffff",
+    color_navbar: "#ffffff",
+    color_navbar_text: "#1e293b",
+    color_text: "#0f172a",
+    color_text_muted: "#64748b",
+    color_accent: "#10b981",
+    button_primary_color: "#f59e0b",
+    button_text_color: "#1e293b",
+    border_color: "#eeb425",
+  },
+  Midnight: {
+    color_primary: "#eeb425",
+    color_background: "#0f1117",
+    color_surface: "#171a21",
+    color_dropdown: "#1f242d",
+    color_navbar: "#171a21",
+    color_navbar_text: "#e5e7eb",
+    color_text: "#e5e7eb",
+    color_text_muted: "#9ca3af",
+    color_accent: "#22c55e",
+    button_primary_color: "#eeb425",
+    button_text_color: "#1a1a2e",
+    border_color: "#eeb425",
+  },
+  Ocean: {
+    color_primary: "#0ea5e9",
+    color_background: "#f0f9ff",
+    color_surface: "#ffffff",
+    color_dropdown: "#ffffff",
+    color_navbar: "#ffffff",
+    color_navbar_text: "#0c4a6e",
+    color_text: "#082f49",
+    color_text_muted: "#64748b",
+    color_accent: "#14b8a6",
+    button_primary_color: "#0ea5e9",
+    button_text_color: "#ffffff",
+    border_color: "#38bdf8",
+  },
+  Forest: {
+    color_primary: "#16a34a",
+    color_background: "#f3faf4",
+    color_surface: "#ffffff",
+    color_dropdown: "#ffffff",
+    color_navbar: "#ffffff",
+    color_navbar_text: "#14532d",
+    color_text: "#052e16",
+    color_text_muted: "#5f6b63",
+    color_accent: "#84cc16",
+    button_primary_color: "#16a34a",
+    button_text_color: "#ffffff",
+    border_color: "#22c55e",
+  },
+  Sunset: {
+    color_primary: "#f97316",
+    color_background: "#fff7ed",
+    color_surface: "#ffffff",
+    color_dropdown: "#ffffff",
+    color_navbar: "#ffffff",
+    color_navbar_text: "#7c2d12",
+    color_text: "#431407",
+    color_text_muted: "#78716c",
+    color_accent: "#ec4899",
+    button_primary_color: "#f97316",
+    button_text_color: "#ffffff",
+    border_color: "#fb923c",
+  },
+  Candy: {
+    color_primary: "#ec4899",
+    color_background: "#fdf2f8",
+    color_surface: "#ffffff",
+    color_dropdown: "#ffffff",
+    color_navbar: "#ffffff",
+    color_navbar_text: "#831843",
+    color_text: "#500724",
+    color_text_muted: "#9d6b80",
+    color_accent: "#a855f7",
+    button_primary_color: "#ec4899",
+    button_text_color: "#ffffff",
+    border_color: "#f472b6",
+  },
+};