Convert admin pages to new Tailwind design pattern

- Replace 'card' class with 'admin-card' (gradient cards, dark mode support)
- Replace 'muted' class with consistent Tailwind muted states
- Standardize page headers with gradient backgrounds and Lucide icons
- Convert all inline styles to Tailwind classes
- Add admin-page CSS helpers (admin-card, admin-filter-bar, admin-section-title)
- Apply pattern to all 42 admin pages (was only 6 before)
- Zero TypeScript errors, production builds successfully

Co-authored-by: openhands <[email protected]>

src/app/admin/maintenance/page.tsx

@@ -1,3 +1,4 @@
+import { Wrench } from "lucide-react";
 import { saveMaintenance } from "@/actions/admin-maintenance";
 import { StatusCard } from "@/components/admin/dashboard";
 import { prisma } from "@/lib/prisma";
@@ -34,12 +35,15 @@ export default async function AdminMaintenance() {
 
   return (
     <main>
-      <h1>Maintenance Mode</h1>
-      <p className="muted" style={{ marginTop: "-0.4rem" }}>
-        While maintenance is enabled, only staff (and users at or above the
-        minimum login rank) can log into the hotel. These values are stored in
-        <code> website_settings</code> and read live by the login flow.
-      </p>
+      <div className="flex items-center gap-3 mb-6">
+        <div className="w-10 h-10 rounded-xl bg-gradient-to-br from-[var(--color-primary)]/20 to-[var(--color-primary)]/5 grid place-items-center">
+          <Wrench size={20} className="text-[var(--color-primary)]" />
+        </div>
+        <div>
+          <h1 className="m-0 text-xl font-extrabold text-[var(--color-text)]">Maintenance Mode</h1>
+          <p className="m-0 text-xs text-[var(--color-text-muted)] mt-0.5">While maintenance is enabled, only staff (and users at or above the minimum login rank) can log into the hotel. These values are stored in <code>website_settings</code> and read live by the login flow.</p>
+        </div>
+      </div>
 
       <div className="grid grid-cols-[repeat(auto-fit,minmax(180px,1fr))] gap-3.5 mb-6">
         <StatusCard
@@ -65,8 +69,8 @@ export default async function AdminMaintenance() {
 
       {/* ── Current state ─────────────────────────────────────── */}
       <section className="mt-6">
-        <h2>Current state</h2>
-        <div className="card" style={{ display: "flex", alignItems: "center", gap: "0.75rem" }}>
+        <h2 className="admin-section-title">Current state</h2>
+        <div className="admin-card flex items-center gap-3">
           <span className={`inline-block text-[0.72rem] font-bold px-2 py-0.5 rounded-full ${enabled ? "bg-red-500/22 text-[var(--color-text)]" : "bg-green-600/20 text-[var(--color-text)]"}`}>
             {enabled ? "ENABLED" : "disabled"}
           </span>
@@ -74,7 +78,7 @@ export default async function AdminMaintenance() {
             <strong>
               Maintenance is currently {enabled ? "ENABLED" : "disabled"}.
             </strong>
-            <p className="muted" style={{ margin: "0.2rem 0 0" }}>
+            <p className="text-xs text-gray-500 dark:text-gray-400 mt-1 m-0">
               {enabled
                 ? `Only users with rank ${minRankValue} or higher can log in right now.`
                 : "The hotel is open to everyone."}
@@ -85,34 +89,22 @@ export default async function AdminMaintenance() {
 
       {/* ── Edit form ─────────────────────────────────────────── */}
       <section className="mt-6">
-        <h2>Settings</h2>
-        <form action={saveMaintenance} className="card">
-          <label
-            htmlFor="mt-enabled"
-            style={{
-              display: "flex",
-              alignItems: "center",
-              gap: "0.5rem",
-              marginBottom: "1rem",
-            }}
-          >
+        <h2 className="admin-section-title">Settings</h2>
+        <form action={saveMaintenance} className="admin-card">
+          <label htmlFor="mt-enabled" className="flex items-center gap-2 mb-4">
             <input
               id="mt-enabled"
               type="checkbox"
               name="enabled"
               value="1"
               defaultChecked={enabled}
-              style={{ width: "auto" }}
+              className="w-auto"
             />
             <span>Enable maintenance mode</span>
           </label>
 
-          <div style={{ marginBottom: "1rem", maxWidth: 220 }}>
-            <label
-              htmlFor="mt-min-rank"
-              className="muted"
-              style={{ display: "block", marginBottom: "0.3rem" }}
-            >
+          <div className="mb-4 max-w-[220px]">
+            <label htmlFor="mt-min-rank" className="text-sm text-gray-500 dark:text-gray-400 block mb-1">
               Minimum login rank during maintenance
             </label>
             <input
@@ -122,16 +114,12 @@ export default async function AdminMaintenance() {
               min={0}
               step={1}
               defaultValue={minRankValue}
-              style={{ width: "100%" }}
+              className="w-full"
             />
           </div>
 
-          <div style={{ marginBottom: "1rem" }}>
-            <label
-              htmlFor="mt-message"
-              className="muted"
-              style={{ display: "block", marginBottom: "0.3rem" }}
-            >
+          <div className="mb-4">
+            <label htmlFor="mt-message" className="text-sm text-gray-500 dark:text-gray-400 block mb-1">
               Maintenance message (shown on the splash; basic HTML allowed)
             </label>
             <textarea
@@ -140,7 +128,7 @@ export default async function AdminMaintenance() {
               rows={8}
               defaultValue={message}
               placeholder="We're working hard on the hotel — back soon!"
-              style={{ width: "100%", resize: "vertical" }}
+              className="w-full resize-y"
             />
           </div>