feat: add animation

app/app.css

@@ -123,3 +123,152 @@
     @apply bg-background text-foreground;
   }
 }
+
+/* ── Animation keyframes ── */
+
+@keyframes fade-in {
+  from { opacity: 0; }
+  to { opacity: 1; }
+}
+
+@keyframes fade-in-up {
+  from { opacity: 0; transform: translateY(16px); }
+  to { opacity: 1; transform: translateY(0); }
+}
+
+@keyframes fade-in-down {
+  from { opacity: 0; transform: translateY(-12px); }
+  to { opacity: 1; transform: translateY(0); }
+}
+
+@keyframes slide-in-left {
+  from { opacity: 0; transform: translateX(-20px); }
+  to { opacity: 1; transform: translateX(0); }
+}
+
+@keyframes scale-in {
+  from { opacity: 0; transform: scale(0.95); }
+  to { opacity: 1; transform: scale(1); }
+}
+
+@keyframes scale-bounce {
+  0% { opacity: 0; transform: scale(0.5); }
+  60% { opacity: 1; transform: scale(1.08); }
+  100% { opacity: 1; transform: scale(1); }
+}
+
+@keyframes float-in {
+  0% { opacity: 0; transform: translateY(24px) scale(0.97); }
+  100% { opacity: 1; transform: translateY(0) scale(1); }
+}
+
+@keyframes shimmer {
+  0% { background-position: -200% 0; }
+  100% { background-position: 200% 0; }
+}
+
+@keyframes pulse-soft {
+  0%, 100% { opacity: 1; }
+  50% { opacity: 0.7; }
+}
+
+/* ── Utility classes ── */
+
+.animate-fade-in {
+  animation: fade-in 0.5s ease-out both;
+}
+
+.animate-fade-in-up {
+  animation: fade-in-up 0.5s ease-out both;
+}
+
+.animate-fade-in-down {
+  animation: fade-in-down 0.4s ease-out both;
+}
+
+.animate-slide-in-left {
+  animation: slide-in-left 0.5s ease-out both;
+}
+
+.animate-scale-in {
+  animation: scale-in 0.4s ease-out both;
+}
+
+.animate-scale-bounce {
+  animation: scale-bounce 0.6s cubic-bezier(0.34, 1.56, 0.64, 1) both;
+}
+
+.animate-float-in {
+  animation: float-in 0.6s cubic-bezier(0.22, 1, 0.36, 1) both;
+}
+
+.animate-shimmer {
+  background: linear-gradient(90deg, transparent 25%, var(--primary) 50%, transparent 75%);
+  background-size: 200% 100%;
+  animation: shimmer 2s infinite;
+}
+
+.animate-pulse-soft {
+  animation: pulse-soft 2s ease-in-out infinite;
+}
+
+/* Stagger delays for children */
+.stagger-1 { animation-delay: 0.05s; }
+.stagger-2 { animation-delay: 0.1s; }
+.stagger-3 { animation-delay: 0.15s; }
+.stagger-4 { animation-delay: 0.2s; }
+.stagger-5 { animation-delay: 0.25s; }
+.stagger-6 { animation-delay: 0.3s; }
+.stagger-7 { animation-delay: 0.35s; }
+.stagger-8 { animation-delay: 0.4s; }
+
+/* Button press effect */
+.btn-press {
+  transition: transform 0.15s ease, box-shadow 0.15s ease;
+}
+.btn-press:hover {
+  transform: translateY(-1px);
+  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
+}
+.btn-press:active {
+  transform: translateY(0.5px);
+  box-shadow: none;
+}
+
+/* Card hover lift */
+.card-hover {
+  transition: transform 0.25s ease, box-shadow 0.25s ease;
+}
+.card-hover:hover {
+  transform: translateY(-4px);
+  box-shadow: 0 12px 24px -8px rgba(0, 0, 0, 0.12);
+}
+
+/* Smooth loading skeleton */
+.skeleton {
+  background: linear-gradient(90deg, var(--muted) 25%, var(--accent) 50%, var(--muted) 75%);
+  background-size: 200% 100%;
+  animation: shimmer 1.5s ease-in-out infinite;
+  border-radius: 0.5rem;
+}
+
+/* Reduced motion preference */
+@media (prefers-reduced-motion: reduce) {
+  .animate-fade-in,
+  .animate-fade-in-up,
+  .animate-fade-in-down,
+  .animate-slide-in-left,
+  .animate-scale-in,
+  .animate-scale-bounce,
+  .animate-float-in {
+    animation: none !important;
+    opacity: 1 !important;
+    transform: none !important;
+  }
+  .card-hover:hover {
+    transform: none;
+  }
+  .btn-press:hover {
+    transform: none;
+  }
+}

app/routes/create-form.tsx

@@ -87,7 +87,7 @@ export default function CreateFormPage() {
             Back to forms
           </Link>
 
-          <h1 className="mb-6 text-2xl font-bold text-foreground">
+          <h1 className="mb-6 text-2xl font-bold text-foreground animate-fade-in-up">
             Create New Form
           </h1>
 
@@ -98,7 +98,7 @@ export default function CreateFormPage() {
               </div>
             )}
 
-            <div className="mb-8 rounded-xl border border-border bg-card p-6 shadow-sm">
+            <div className="mb-8 rounded-xl border border-border bg-card p-6 shadow-sm animate-float-in" style={{ animationDelay: '0.1s' }}>
               <div className="h-2 -mx-6 -mt-6 mb-6 rounded-t-xl bg-primary" />
               <div className="flex flex-col gap-4">
                 <FormInput

app/routes/edit-form.tsx

@@ -123,7 +123,7 @@ export default function EditFormPage() {
             Back to form
           </Link>
 
-          <h1 className="mb-6 text-2xl font-bold text-foreground">
+          <h1 className="mb-6 text-2xl font-bold text-foreground animate-fade-in-up">
             Edit Form
           </h1>
 
@@ -134,7 +134,7 @@ export default function EditFormPage() {
               </div>
             )}
 
-            <div className="mb-8 rounded-xl border border-border bg-card p-6 shadow-sm">
+            <div className="mb-8 rounded-xl border border-border bg-card p-6 shadow-sm animate-float-in" style={{ animationDelay: '0.1s' }}>
               <div className="h-2 -mx-6 -mt-6 mb-6 rounded-t-xl bg-primary" />
               <div className="flex flex-col gap-4">
                 <FormInput

app/routes/form-responses.tsx

@@ -130,7 +130,7 @@ export default function FormResponsesPage() {
           </Link>
 
           {/* Header */}
-          <div className="mb-8 rounded-xl border border-border bg-card shadow-sm">
+          <div className="mb-8 rounded-xl border border-border bg-card shadow-sm animate-float-in">
             <div className="h-2 rounded-t-xl bg-primary" />
             <div className="p-6">
               <div className="flex flex-col gap-4 sm:flex-row sm:items-start sm:justify-between">
@@ -183,7 +183,7 @@ export default function FormResponsesPage() {
           </div>
 
           {/* Tabs */}
-          <div className="mb-6 flex gap-1 rounded-lg border border-border bg-card p-1">
+          <div className="mb-6 flex gap-1 rounded-lg border border-border bg-card p-1 animate-fade-in-up" style={{ animationDelay: '0.15s' }}>
             <button
               onClick={() => setActiveTab("summary")}
               className={`flex-1 rounded-md px-4 py-2 text-sm font-medium transition-colors ${

app/routes/form.tsx

@@ -104,7 +104,7 @@ export default function FormPreviewPage() {
             Back to forms
           </Link>
 
-          <div className="mb-8 rounded-xl border border-border bg-card shadow-sm">
+          <div className="mb-8 rounded-xl border border-border bg-card shadow-sm animate-float-in">
             <div className="h-2 rounded-t-xl bg-primary" />
             <div className="p-6">
               <div className="mb-4 flex flex-wrap items-center gap-3">
@@ -172,15 +172,16 @@ export default function FormPreviewPage() {
 
           <div className="flex flex-col gap-4">
             {form.questions.map((question, index) => (
-              <QuestionPreview
-                key={question.id}
-                question={question}
-                index={index}
-              />
+              <div key={question.id} className="animate-fade-in-up" style={{ animationDelay: `${0.15 + index * 0.08}s` }}>
+                <QuestionPreview
+                  question={question}
+                  index={index}
+                />
+              </div>
             ))}
           </div>
 
-          <div className="mt-8 flex flex-col items-center gap-3 rounded-xl border border-dashed border-border bg-card/50 p-6">
+          <div className="mt-8 flex flex-col items-center gap-3 rounded-xl border border-dashed border-border bg-card/50 p-6 animate-fade-in" style={{ animationDelay: '0.4s' }}>
             <p className="text-sm text-muted-foreground">
               This is a read-only preview. Click below to fill out this form.
             </p>

app/routes/forms.tsx

@@ -207,8 +207,10 @@ export default function FormsPage() {
             </div>
           ) : forms.length > 0 ? (
             <div className="grid gap-5 sm:grid-cols-2">
-              {forms.map((form) => (
-                <FormCard key={form.id} form={form} />
+              {forms.map((form, index) => (
+                <div key={form.id} className="animate-float-in" style={{ animationDelay: `${index * 0.08}s` }}>
+                  <FormCard form={form} />
+                </div>
               ))}
             </div>
           ) : (

app/routes/login.tsx

@@ -58,7 +58,7 @@ export default function LoginPage() {
     <div className="flex min-h-screen flex-col bg-background">
       <div className="flex flex-1 items-center justify-center px-4 py-12">
         <div className="w-full max-w-md">
-          <div className="mb-8 flex flex-col items-center gap-3">
+          <div className="mb-8 flex flex-col items-center gap-3 animate-fade-in-down">
             <h1 className="text-2xl font-bold text-foreground">
               Welcome back
             </h1>
@@ -67,7 +67,7 @@ export default function LoginPage() {
             </p>
           </div>
 
-          <div className="rounded-xl border border-border bg-card p-6 shadow-sm">
+          <div className="rounded-xl border border-border bg-card p-6 shadow-sm animate-float-in" style={{ animationDelay: '0.15s' }}>
             <form onSubmit={handleSubmit} className="flex flex-col gap-4">
               {errors.general && (
                 <p className="rounded-lg bg-destructive/10 px-3 py-2 text-sm text-destructive">
@@ -127,7 +127,7 @@ export default function LoginPage() {
             </form>
           </div>
 
-          <p className="mt-6 text-center text-sm text-muted-foreground">
+          <p className="mt-6 text-center text-sm text-muted-foreground animate-fade-in" style={{ animationDelay: '0.3s' }}>
             {"Don't have an account? "}
             <Link
               to="/register"

app/routes/not-found.tsx

@@ -4,10 +4,10 @@ export function meta() {
 
 export default function NotFound() {
   return (
-    <div style={{ textAlign: "center", padding: "4rem" }}>
-      <h1>404</h1>
-      <p>Page not found.</p>
-      <a href="/">Go home</a>
+    <div className="flex min-h-screen flex-col items-center justify-center bg-background px-4" style={{ textAlign: "center" }}>
+      <h1 className="text-6xl font-bold text-foreground animate-scale-bounce">404</h1>
+      <p className="mt-4 text-lg text-muted-foreground animate-fade-in-up" style={{ animationDelay: '0.2s' }}>Page not found.</p>
+      <a href="/" className="mt-6 inline-flex items-center gap-2 rounded-lg bg-primary px-6 py-3 text-sm font-medium text-primary-foreground btn-press animate-fade-in-up" style={{ animationDelay: '0.35s' }}>Go home</a>
     </div>
   );
 }

app/routes/register.tsx

@@ -64,7 +64,7 @@ export default function RegisterPage() {
         <div className="flex min-h-screen flex-col bg-background">
             <div className="flex flex-1 items-center justify-center px-4 py-12">
                 <div className="w-full max-w-md">
-                    <div className="mb-8 flex flex-col items-center gap-3">
+                    <div className="mb-8 flex flex-col items-center gap-3 animate-fade-in-down">
                         <h1 className="text-2xl font-bold text-foreground">
                             Create your account
                         </h1>
@@ -73,7 +73,7 @@ export default function RegisterPage() {
                         </p>
                     </div>
 
-                    <div className="rounded-xl border border-border bg-card p-6 shadow-sm">
+                    <div className="rounded-xl border border-border bg-card p-6 shadow-sm animate-float-in" style={{ animationDelay: '0.15s' }}>
                         <form onSubmit={handleSubmit} className="flex flex-col gap-4">
                             <div className="flex gap-3">
                                 <FormInput
@@ -142,7 +142,7 @@ export default function RegisterPage() {
                         </form>
                     </div>
 
-                    <p className="mt-6 text-center text-sm text-muted-foreground">
+                    <p className="mt-6 text-center text-sm text-muted-foreground animate-fade-in" style={{ animationDelay: '0.3s' }}>
                         Already have an account?{" "}
                         <Link
                             to="/login"

app/routes/submit-form.tsx

@@ -140,8 +140,8 @@ export default function SubmitFormPage() {
       <div className="flex min-h-screen flex-col bg-background">
         <Navbar />
         <main className="flex flex-1 items-center justify-center">
-          <div className="mx-4 flex max-w-md flex-col items-center rounded-xl border border-border bg-card p-8 text-center shadow-sm">
-            <div className="mb-4 flex h-16 w-16 items-center justify-center rounded-full bg-green-100 dark:bg-green-900/30">
+          <div className="mx-4 flex max-w-md flex-col items-center rounded-xl border border-border bg-card p-8 text-center shadow-sm animate-scale-in">
+            <div className="mb-4 flex h-16 w-16 items-center justify-center rounded-full bg-green-100 dark:bg-green-900/30 animate-scale-bounce">
               <CheckCircle2 className="h-8 w-8 text-green-600 dark:text-green-400" />
             </div>
             <h2 className="text-xl font-bold text-foreground">
@@ -198,7 +198,7 @@ export default function SubmitFormPage() {
             Back to form preview
           </Link>
 
-          <div className="mb-8 rounded-xl border border-border bg-card shadow-sm">
+          <div className="mb-8 rounded-xl border border-border bg-card shadow-sm animate-float-in">
             <div className="h-2 rounded-t-xl bg-primary" />
             <div className="p-6">
               <h1 className="text-xl font-bold text-foreground text-balance sm:text-2xl">
@@ -223,14 +223,15 @@ export default function SubmitFormPage() {
 
           <form onSubmit={handleSubmit} className="flex flex-col gap-4">
             {form.questions.map((question, index) => (
-              <QuestionField
-                key={question.id}
-                question={question}
-                index={index}
-                value={answers[question.id] ?? ""}
-                onChange={(val) => updateAnswer(question.id, val)}
-                error={validationErrors[question.id]}
-              />
+              <div key={question.id} className="animate-fade-in-up" style={{ animationDelay: `${0.1 + index * 0.08}s` }}>
+                <QuestionField
+                  question={question}
+                  index={index}
+                  value={answers[question.id] ?? ""}
+                  onChange={(val) => updateAnswer(question.id, val)}
+                  error={validationErrors[question.id]}
+                />
+              </div>
             ))}
 
             <div className="mt-4 flex items-center justify-between">