feat: comprehensive UI polish with responsive design, animations, and modern styling

- Rewrite globals.css with professional utility classes (btn-primary/secondary/danger/ghost, input-field, card/card-hover, badge system, stat-card, skeleton, page-header, animations)
- Responsive dashboard layout with mobile hamburger menu, slide-out sidebar, backdrop overlay
- Polish login/register pages with gradient backgrounds, slide-up animations, loading spinners
- Dashboard home with stat cards grid (2-col mobile, 4-col desktop), skeleton loading, empty states
- Apps list with desktop table + mobile card views, proper badges
- Deploy wizard with responsive step indicator (checkmarks, progress line), mobile-friendly forms
- App detail page with responsive header/action buttons, improved logs tabs, resource scaling
- Admin users page with desktop table + mobile cards, skeleton loading
- Admin clusters page with responsive layout, animated resource panel
- Admin pools page with responsive form grids, improved pool cards
- Consistent rounded-2xl cards, rounded-xl buttons/inputs, active:scale feedback throughout

frontend/src/app/register/page.tsx

@@ -27,37 +27,38 @@ export default function RegisterPage() {
   };
 
   return (
-    <div className="min-h-screen flex items-center justify-center bg-gray-50 py-12 px-4">
-      <div className="max-w-md w-full space-y-8">
+    <div className="min-h-screen flex items-center justify-center bg-gradient-to-br from-gray-50 via-white to-primary-50 py-12 px-4">
+      <div className="max-w-md w-full space-y-8 animate-slide-up">
         <div className="text-center">
-          <h1 className="text-3xl font-bold text-primary-600">☁️ CloudHost</h1>
-          <h2 className="mt-4 text-2xl font-semibold text-gray-900">Create your account</h2>
-          <p className="mt-2 text-gray-600">
-            Already have an account?{' '}
-            <Link href="/login" className="text-primary-600 hover:text-primary-500 font-medium">
-              Sign in
-            </Link>
+          <div className="inline-flex items-center justify-center w-16 h-16 rounded-2xl bg-primary-100 mb-4">
+            <span className="text-3xl">☁️</span>
+          </div>
+          <h1 className="text-3xl font-bold text-gray-900 tracking-tight">Create your account</h1>
+          <p className="mt-2 text-gray-500">
+            Start deploying apps in minutes
           </p>
         </div>
 
-        <form className="card space-y-6" onSubmit={handleSubmit}>
-          <div className="grid grid-cols-2 gap-4">
+        <form className="card space-y-5" onSubmit={handleSubmit}>
+          <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
             <div>
-              <label className="block text-sm font-medium text-gray-700 mb-1">First name</label>
+              <label className="block text-sm font-medium text-gray-700 mb-1.5">First name</label>
               <input
                 type="text"
                 required
                 className="input-field"
+                placeholder="John"
                 value={form.firstName}
                 onChange={(e) => setForm({ ...form, firstName: e.target.value })}
               />
             </div>
             <div>
-              <label className="block text-sm font-medium text-gray-700 mb-1">Last name</label>
+              <label className="block text-sm font-medium text-gray-700 mb-1.5">Last name</label>
               <input
                 type="text"
                 required
                 className="input-field"
+                placeholder="Doe"
                 value={form.lastName}
                 onChange={(e) => setForm({ ...form, lastName: e.target.value })}
               />
@@ -65,7 +66,7 @@ export default function RegisterPage() {
           </div>
 
           <div>
-            <label className="block text-sm font-medium text-gray-700 mb-1">Email address</label>
+            <label className="block text-sm font-medium text-gray-700 mb-1.5">Email address</label>
             <input
               type="email"
               required
@@ -77,7 +78,7 @@ export default function RegisterPage() {
           </div>
 
           <div>
-            <label className="block text-sm font-medium text-gray-700 mb-1">Password</label>
+            <label className="block text-sm font-medium text-gray-700 mb-1.5">Password</label>
             <input
               type="password"
               required
@@ -90,8 +91,22 @@ export default function RegisterPage() {
           </div>
 
           <button type="submit" disabled={isLoading} className="btn-primary w-full">
-            {isLoading ? 'Creating account...' : 'Create account'}
+            {isLoading ? (
+              <>
+                <div className="animate-spin rounded-full h-4 w-4 border-2 border-white border-t-transparent" />
+                Creating account...
+              </>
+            ) : (
+              'Create account'
+            )}
           </button>
+
+          <p className="text-center text-sm text-gray-500">
+            Already have an account?{' '}
+            <Link href="/login" className="text-primary-600 hover:text-primary-500 font-semibold">
+              Sign in
+            </Link>
+          </p>
         </form>
       </div>
     </div>