diff --git a/frontend/src/app/dev/forms/page.tsx b/frontend/src/app/dev/forms/page.tsx
new file mode 100644
index 0000000..f450529
--- /dev/null
+++ b/frontend/src/app/dev/forms/page.tsx
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+/**
+ * Form Patterns Demo
+ * Interactive demonstrations of form patterns with validation
+ * Access: /dev/forms
+ */
+
+'use client';
+
+import { useState } from 'react';
+import Link from 'next/link';
+import { useForm } from 'react-hook-form';
+import { zodResolver } from '@hookform/resolvers/zod';
+import { z } from 'zod';
+import { ArrowLeft, CheckCircle2, Loader2 } from 'lucide-react';
+import { Button } from '@/components/ui/button';
+import {
+  Card,
+  CardContent,
+  CardDescription,
+  CardHeader,
+  CardTitle,
+} from '@/components/ui/card';
+import { Input } from '@/components/ui/input';
+import { Label } from '@/components/ui/label';
+import { Textarea } from '@/components/ui/textarea';
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from '@/components/ui/select';
+import { Checkbox } from '@/components/ui/checkbox';
+import { Badge } from '@/components/ui/badge';
+import { Alert, AlertDescription, AlertTitle } from '@/components/ui/alert';
+import { Example, ExampleSection } from '@/components/dev/Example';
+import { BeforeAfter } from '@/components/dev/BeforeAfter';
+
+// Example schemas
+const loginSchema = z.object({
+  email: z.string().email('Invalid email address'),
+  password: z.string().min(8, 'Password must be at least 8 characters'),
+});
+
+const contactSchema = z.object({
+  name: z.string().min(1, 'Name is required'),
+  email: z.string().email('Invalid email address'),
+  message: z.string().min(10, 'Message must be at least 10 characters'),
+  category: z.string().min(1, 'Please select a category'),
+});
+
+type LoginForm = z.infer<typeof loginSchema>;
+type ContactForm = z.infer<typeof contactSchema>;
+
+export default function FormsPage() {
+  const [isSubmitting, setIsSubmitting] = useState(false);
+  const [submitSuccess, setSubmitSuccess] = useState(false);
+
+  // Login form
+  const {
+    register: registerLogin,
+    handleSubmit: handleSubmitLogin,
+    formState: { errors: errorsLogin },
+  } = useForm<LoginForm>({
+    resolver: zodResolver(loginSchema),
+  });
+
+  // Contact form
+  const {
+    register: registerContact,
+    handleSubmit: handleSubmitContact,
+    formState: { errors: errorsContact },
+    setValue: setValueContact,
+  } = useForm<ContactForm>({
+    resolver: zodResolver(contactSchema),
+  });
+
+  const onSubmitLogin = async (data: LoginForm) => {
+    setIsSubmitting(true);
+    setSubmitSuccess(false);
+    // Simulate API call
+    await new Promise((resolve) => setTimeout(resolve, 1500));
+    console.log('Login form data:', data);
+    setIsSubmitting(false);
+    setSubmitSuccess(true);
+  };
+
+  const onSubmitContact = async (data: ContactForm) => {
+    setIsSubmitting(true);
+    setSubmitSuccess(false);
+    // Simulate API call
+    await new Promise((resolve) => setTimeout(resolve, 1500));
+    console.log('Contact form data:', data);
+    setIsSubmitting(false);
+    setSubmitSuccess(true);
+  };
+
+  return (
+    <div className="min-h-screen bg-background">
+      {/* Header */}
+      <header className="sticky top-0 z-50 w-full border-b bg-background/95 backdrop-blur supports-[backdrop-filter]:bg-background/60">
+        <div className="container mx-auto flex h-16 items-center gap-4 px-4">
+          <Link href="/dev">
+            <Button variant="ghost" size="icon" aria-label="Back to hub">
+              <ArrowLeft className="h-5 w-5" />
+            </Button>
+          </Link>
+          <div>
+            <h1 className="text-xl font-bold">Form Patterns</h1>
+            <p className="text-sm text-muted-foreground">
+              react-hook-form + Zod validation examples
+            </p>
+          </div>
+        </div>
+      </header>
+
+      {/* Content */}
+      <main className="container mx-auto px-4 py-8">
+        <div className="space-y-12">
+          {/* Introduction */}
+          <div className="max-w-3xl space-y-4">
+            <p className="text-muted-foreground">
+              Complete form implementations using react-hook-form for state management
+              and Zod for validation. Includes error handling, loading states, and
+              accessibility features.
+            </p>
+            <div className="flex flex-wrap gap-2">
+              <Badge variant="outline">react-hook-form</Badge>
+              <Badge variant="outline">Zod</Badge>
+              <Badge variant="outline">Validation</Badge>
+              <Badge variant="outline">ARIA</Badge>
+            </div>
+          </div>
+
+          {/* Basic Form */}
+          <ExampleSection
+            id="basic-form"
+            title="Basic Form with Validation"
+            description="Login form with email and password validation"
+          >
+            <Example
+              title="Login Form"
+              description="Validates on submit, shows field-level errors"
+              code={`const schema = z.object({
+  email: z.string().email('Invalid email'),
+  password: z.string().min(8, 'Min 8 chars'),
+});
+
+const { register, handleSubmit, formState: { errors } } = useForm({
+  resolver: zodResolver(schema),
+});
+
+<form onSubmit={handleSubmit(onSubmit)} className="space-y-4">
+  <div className="space-y-2">
+    <Label htmlFor="email">Email</Label>
+    <Input
+      id="email"
+      type="email"
+      {...register('email')}
+      aria-invalid={!!errors.email}
+    />
+    {errors.email && (
+      <p className="text-sm text-destructive">
+        {errors.email.message}
+      </p>
+    )}
+  </div>
+  <Button type="submit" disabled={isSubmitting}>
+    {isSubmitting ? <Loader2 className="animate-spin" /> : 'Submit'}
+  </Button>
+</form>`}
+            >
+              <div className="max-w-md mx-auto">
+                <form onSubmit={handleSubmitLogin(onSubmitLogin)} className="space-y-4">
+                  {/* Email */}
+                  <div className="space-y-2">
+                    <Label htmlFor="login-email">Email</Label>
+                    <Input
+                      id="login-email"
+                      type="email"
+                      placeholder="you@example.com"
+                      {...registerLogin('email')}
+                      aria-invalid={!!errorsLogin.email}
+                      aria-describedby={
+                        errorsLogin.email ? 'login-email-error' : undefined
+                      }
+                    />
+                    {errorsLogin.email && (
+                      <p
+                        id="login-email-error"
+                        className="text-sm text-destructive"
+                        role="alert"
+                      >
+                        {errorsLogin.email.message}
+                      </p>
+                    )}
+                  </div>
+
+                  {/* Password */}
+                  <div className="space-y-2">
+                    <Label htmlFor="login-password">Password</Label>
+                    <Input
+                      id="login-password"
+                      type="password"
+                      placeholder="••••••••"
+                      {...registerLogin('password')}
+                      aria-invalid={!!errorsLogin.password}
+                      aria-describedby={
+                        errorsLogin.password ? 'login-password-error' : undefined
+                      }
+                    />
+                    {errorsLogin.password && (
+                      <p
+                        id="login-password-error"
+                        className="text-sm text-destructive"
+                        role="alert"
+                      >
+                        {errorsLogin.password.message}
+                      </p>
+                    )}
+                  </div>
+
+                  {/* Submit */}
+                  <Button type="submit" className="w-full" disabled={isSubmitting}>
+                    {isSubmitting && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
+                    {isSubmitting ? 'Signing In...' : 'Sign In'}
+                  </Button>
+
+                  {/* Success Message */}
+                  {submitSuccess && (
+                    <Alert className="border-green-500 text-green-600 dark:border-green-400 dark:text-green-400">
+                      <CheckCircle2 className="h-4 w-4" />
+                      <AlertTitle>Success!</AlertTitle>
+                      <AlertDescription>Form submitted successfully.</AlertDescription>
+                    </Alert>
+                  )}
+                </form>
+              </div>
+            </Example>
+          </ExampleSection>
+
+          {/* Complete Form */}
+          <ExampleSection
+            id="complete-form"
+            title="Complete Form Example"
+            description="Contact form with multiple field types"
+          >
+            <Example
+              title="Contact Form"
+              description="Text, textarea, select, and validation"
+              code={`const schema = z.object({
+  name: z.string().min(1, 'Name is required'),
+  email: z.string().email('Invalid email'),
+  message: z.string().min(10, 'Min 10 characters'),
+  category: z.string().min(1, 'Select a category'),
+});
+
+<form onSubmit={handleSubmit(onSubmit)} className="space-y-4">
+  {/* Input field */}
+  <div className="space-y-2">
+    <Label htmlFor="name">Name</Label>
+    <Input {...register('name')} />
+    {errors.name && <p className="text-sm text-destructive">{errors.name.message}</p>}
+  </div>
+
+  {/* Textarea field */}
+  <div className="space-y-2">
+    <Label htmlFor="message">Message</Label>
+    <Textarea {...register('message')} rows={4} />
+    {errors.message && <p className="text-sm text-destructive">{errors.message.message}</p>}
+  </div>
+
+  {/* Select field */}
+  <div className="space-y-2">
+    <Label htmlFor="category">Category</Label>
+    <Select onValueChange={(value) => setValue('category', value)}>
+      <SelectTrigger>
+        <SelectValue placeholder="Select..." />
+      </SelectTrigger>
+      <SelectContent>
+        <SelectItem value="support">Support</SelectItem>
+        <SelectItem value="sales">Sales</SelectItem>
+      </SelectContent>
+    </Select>
+  </div>
+
+  <Button type="submit">Submit</Button>
+</form>`}
+            >
+              <div className="max-w-md mx-auto">
+                <form
+                  onSubmit={handleSubmitContact(onSubmitContact)}
+                  className="space-y-4"
+                >
+                  {/* Name */}
+                  <div className="space-y-2">
+                    <Label htmlFor="contact-name">Name</Label>
+                    <Input
+                      id="contact-name"
+                      placeholder="John Doe"
+                      {...registerContact('name')}
+                      aria-invalid={!!errorsContact.name}
+                    />
+                    {errorsContact.name && (
+                      <p className="text-sm text-destructive" role="alert">
+                        {errorsContact.name.message}
+                      </p>
+                    )}
+                  </div>
+
+                  {/* Email */}
+                  <div className="space-y-2">
+                    <Label htmlFor="contact-email">Email</Label>
+                    <Input
+                      id="contact-email"
+                      type="email"
+                      placeholder="you@example.com"
+                      {...registerContact('email')}
+                      aria-invalid={!!errorsContact.email}
+                    />
+                    {errorsContact.email && (
+                      <p className="text-sm text-destructive" role="alert">
+                        {errorsContact.email.message}
+                      </p>
+                    )}
+                  </div>
+
+                  {/* Category */}
+                  <div className="space-y-2">
+                    <Label htmlFor="contact-category">Category</Label>
+                    <Select
+                      onValueChange={(value) => setValueContact('category', value)}
+                    >
+                      <SelectTrigger id="contact-category">
+                        <SelectValue placeholder="Select a category" />
+                      </SelectTrigger>
+                      <SelectContent>
+                        <SelectItem value="support">Support</SelectItem>
+                        <SelectItem value="sales">Sales</SelectItem>
+                        <SelectItem value="feedback">Feedback</SelectItem>
+                      </SelectContent>
+                    </Select>
+                    {errorsContact.category && (
+                      <p className="text-sm text-destructive" role="alert">
+                        {errorsContact.category.message}
+                      </p>
+                    )}
+                  </div>
+
+                  {/* Message */}
+                  <div className="space-y-2">
+                    <Label htmlFor="contact-message">Message</Label>
+                    <Textarea
+                      id="contact-message"
+                      placeholder="Type your message here..."
+                      rows={4}
+                      {...registerContact('message')}
+                      aria-invalid={!!errorsContact.message}
+                    />
+                    {errorsContact.message && (
+                      <p className="text-sm text-destructive" role="alert">
+                        {errorsContact.message.message}
+                      </p>
+                    )}
+                  </div>
+
+                  {/* Submit */}
+                  <Button type="submit" className="w-full" disabled={isSubmitting}>
+                    {isSubmitting && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
+                    {isSubmitting ? 'Sending...' : 'Send Message'}
+                  </Button>
+
+                  {/* Success Message */}
+                  {submitSuccess && (
+                    <Alert className="border-green-500 text-green-600 dark:border-green-400 dark:text-green-400">
+                      <CheckCircle2 className="h-4 w-4" />
+                      <AlertTitle>Success!</AlertTitle>
+                      <AlertDescription>
+                        Your message has been sent successfully.
+                      </AlertDescription>
+                    </Alert>
+                  )}
+                </form>
+              </div>
+            </Example>
+          </ExampleSection>
+
+          {/* Error States */}
+          <ExampleSection
+            id="error-states"
+            title="Error State Handling"
+            description="Proper ARIA attributes and visual feedback"
+          >
+            <BeforeAfter
+              title="Error State Best Practices"
+              description="Use aria-invalid and aria-describedby for accessibility"
+              before={{
+                caption: "No ARIA attributes, poor accessibility",
+                content: (
+                  <div className="space-y-2 rounded-lg border p-4">
+                    <div className="text-sm font-medium">Email</div>
+                    <div className="h-10 rounded-md border border-destructive bg-background"></div>
+                    <p className="text-sm text-destructive">Invalid email address</p>
+                  </div>
+                ),
+              }}
+              after={{
+                caption: "With ARIA, screen reader accessible",
+                content: (
+                  <div className="space-y-2 rounded-lg border p-4">
+                    <div className="text-sm font-medium">Email</div>
+                    <div
+                      className="h-10 rounded-md border border-destructive bg-background"
+                      role="textbox"
+                      aria-invalid="true"
+                      aria-describedby="email-error"
+                    >
+                      <span className="sr-only">Email input with error</span>
+                    </div>
+                    <p id="email-error" className="text-sm text-destructive" role="alert">
+                      Invalid email address
+                    </p>
+                  </div>
+                ),
+              }}
+            />
+
+            <Card className="mt-6">
+              <CardHeader>
+                <CardTitle className="text-base">Error Handling Checklist</CardTitle>
+              </CardHeader>
+              <CardContent>
+                <ul className="space-y-2 text-sm">
+                  <li className="flex items-start gap-2">
+                    <CheckCircle2 className="h-4 w-4 text-green-600 mt-0.5" />
+                    <span>Add <code className="text-xs">aria-invalid=true</code> to invalid inputs</span>
+                  </li>
+                  <li className="flex items-start gap-2">
+                    <CheckCircle2 className="h-4 w-4 text-green-600 mt-0.5" />
+                    <span>Link errors with <code className="text-xs">aria-describedby</code></span>
+                  </li>
+                  <li className="flex items-start gap-2">
+                    <CheckCircle2 className="h-4 w-4 text-green-600 mt-0.5" />
+                    <span>Add <code className="text-xs">role="alert"</code> to error messages</span>
+                  </li>
+                  <li className="flex items-start gap-2">
+                    <CheckCircle2 className="h-4 w-4 text-green-600 mt-0.5" />
+                    <span>Visual indicator (red border, icon)</span>
+                  </li>
+                  <li className="flex items-start gap-2">
+                    <CheckCircle2 className="h-4 w-4 text-green-600 mt-0.5" />
+                    <span>Clear error message text</span>
+                  </li>
+                </ul>
+              </CardContent>
+            </Card>
+          </ExampleSection>
+
+          {/* Loading States */}
+          <ExampleSection
+            id="loading-states"
+            title="Loading States"
+            description="Proper feedback during async operations"
+          >
+            <div className="grid gap-6 lg:grid-cols-2">
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">Button Loading State</CardTitle>
+                </CardHeader>
+                <CardContent className="space-y-4">
+                  <code className="text-xs block">
+                    {`<Button disabled={isLoading}>
+  {isLoading && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
+  {isLoading ? 'Saving...' : 'Save'}
+</Button>`}
+                  </code>
+                  <div className="flex gap-2">
+                    <Button size="sm">Save</Button>
+                    <Button size="sm" disabled>
+                      <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+                      Saving...
+                    </Button>
+                  </div>
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">Form Disabled State</CardTitle>
+                </CardHeader>
+                <CardContent>
+                  <code className="text-xs block mb-3">
+                    {`<fieldset disabled={isLoading}>
+  <Input />
+  <Button type="submit" />
+</fieldset>`}
+                  </code>
+                  <div className="space-y-2 opacity-60">
+                    <Input placeholder="Disabled input" disabled />
+                    <Button size="sm" disabled className="w-full">
+                      Disabled Button
+                    </Button>
+                  </div>
+                </CardContent>
+              </Card>
+            </div>
+          </ExampleSection>
+
+          {/* Zod Patterns */}
+          <ExampleSection
+            id="zod-patterns"
+            title="Common Zod Validation Patterns"
+            description="Reusable validation schemas"
+          >
+            <Card>
+              <CardHeader>
+                <CardTitle>Validation Pattern Library</CardTitle>
+              </CardHeader>
+              <CardContent className="space-y-4">
+                <div className="space-y-2">
+                  <div className="font-medium text-sm">Required String</div>
+                  <code className="block rounded bg-muted p-2 text-xs">
+                    z.string().min(1, &quot;Required&quot;)
+                  </code>
+                </div>
+
+                <div className="space-y-2">
+                  <div className="font-medium text-sm">Email</div>
+                  <code className="block rounded bg-muted p-2 text-xs">
+                    z.string().email(&quot;Invalid email&quot;)
+                  </code>
+                </div>
+
+                <div className="space-y-2">
+                  <div className="font-medium text-sm">Password (min length)</div>
+                  <code className="block rounded bg-muted p-2 text-xs">
+                    z.string().min(8, &quot;Min 8 characters&quot;)
+                  </code>
+                </div>
+
+                <div className="space-y-2">
+                  <div className="font-medium text-sm">Number Range</div>
+                  <code className="block rounded bg-muted p-2 text-xs">
+                    z.coerce.number().min(0).max(100)
+                  </code>
+                </div>
+
+                <div className="space-y-2">
+                  <div className="font-medium text-sm">Optional Field</div>
+                  <code className="block rounded bg-muted p-2 text-xs">
+                    z.string().optional()
+                  </code>
+                </div>
+
+                <div className="space-y-2">
+                  <div className="font-medium text-sm">Password Confirmation</div>
+                  <code className="block rounded bg-muted p-2 text-xs">
+                    {`z.object({
+  password: z.string().min(8),
+  confirmPassword: z.string()
+}).refine(data => data.password === data.confirmPassword, {
+  message: "Passwords don't match",
+  path: ["confirmPassword"]
+})`}
+                  </code>
+                </div>
+              </CardContent>
+            </Card>
+          </ExampleSection>
+        </div>
+      </main>
+
+      {/* Footer */}
+      <footer className="mt-16 border-t py-6">
+        <div className="container mx-auto px-4 text-center">
+          <p className="text-sm text-muted-foreground">
+            Learn more:{' '}
+            <a
+              href="/docs/design-system/06-forms.md"
+              target="_blank"
+              rel="noopener noreferrer"
+              className="font-medium hover:text-foreground"
+            >
+              Forms Documentation
+            </a>
+          </p>
+        </div>
+      </footer>
+    </div>
+  );
+}
diff --git a/frontend/src/app/dev/layouts/page.tsx b/frontend/src/app/dev/layouts/page.tsx
new file mode 100644
index 0000000..b37b2d0
--- /dev/null
+++ b/frontend/src/app/dev/layouts/page.tsx
@@ -0,0 +1,524 @@
+/**
+ * Layout Patterns Demo
+ * Interactive demonstrations of essential layout patterns
+ * Access: /dev/layouts
+ */
+
+import type { Metadata } from 'next';
+import Link from 'next/link';
+import { ArrowLeft, Grid3x3, LayoutDashboard } from 'lucide-react';
+import { Button } from '@/components/ui/button';
+import {
+  Card,
+  CardContent,
+  CardDescription,
+  CardHeader,
+  CardTitle,
+} from '@/components/ui/card';
+import { Badge } from '@/components/ui/badge';
+import { Example, ExampleSection } from '@/components/dev/Example';
+import { BeforeAfter } from '@/components/dev/BeforeAfter';
+
+export const metadata: Metadata = {
+  title: 'Layout Patterns | Dev',
+  description: 'Essential layout patterns with before/after examples',
+};
+
+export default function LayoutsPage() {
+  return (
+    <div className="min-h-screen bg-background">
+      {/* Header */}
+      <header className="sticky top-0 z-50 w-full border-b bg-background/95 backdrop-blur supports-[backdrop-filter]:bg-background/60">
+        <div className="container mx-auto flex h-16 items-center gap-4 px-4">
+          <Link href="/dev">
+            <Button variant="ghost" size="icon" aria-label="Back to hub">
+              <ArrowLeft className="h-5 w-5" />
+            </Button>
+          </Link>
+          <div>
+            <h1 className="text-xl font-bold">Layout Patterns</h1>
+            <p className="text-sm text-muted-foreground">
+              Essential patterns for pages, dashboards, and forms
+            </p>
+          </div>
+        </div>
+      </header>
+
+      {/* Content */}
+      <main className="container mx-auto px-4 py-8">
+        <div className="space-y-12">
+          {/* Introduction */}
+          <div className="max-w-3xl space-y-4">
+            <p className="text-muted-foreground">
+              These 5 essential layout patterns cover 80% of interface needs. Each
+              pattern includes live examples, before/after comparisons, and copy-paste
+              code.
+            </p>
+            <div className="flex flex-wrap gap-2">
+              <Badge variant="outline">Grid vs Flex</Badge>
+              <Badge variant="outline">Responsive</Badge>
+              <Badge variant="outline">Mobile-first</Badge>
+              <Badge variant="outline">Best practices</Badge>
+            </div>
+          </div>
+
+          {/* 1. Page Container */}
+          <ExampleSection
+            id="page-container"
+            title="1. Page Container"
+            description="Standard page layout with constrained width"
+          >
+            <Example
+              title="Page Container Pattern"
+              description="Responsive container with padding and max-width"
+              code={`<div className="container mx-auto px-4 py-8">
+  <div className="max-w-4xl mx-auto space-y-6">
+    <h1 className="text-3xl font-bold">Page Title</h1>
+    <Card>
+      <CardHeader>
+        <CardTitle>Content Card</CardTitle>
+      </CardHeader>
+      <CardContent>
+        <p>Your main content goes here.</p>
+      </CardContent>
+    </Card>
+  </div>
+</div>`}
+            >
+              <div className="rounded-lg border bg-muted/30 p-2">
+                <div className="container mx-auto px-4 py-8 bg-background rounded">
+                  <div className="max-w-4xl mx-auto space-y-6">
+                    <h2 className="text-2xl font-bold">Page Title</h2>
+                    <Card>
+                      <CardHeader>
+                        <CardTitle>Content Card</CardTitle>
+                        <CardDescription>
+                          Constrained to max-w-4xl for readability
+                        </CardDescription>
+                      </CardHeader>
+                      <CardContent>
+                        <p className="text-sm text-muted-foreground">
+                          Your main content goes here. The max-w-4xl constraint
+                          ensures comfortable reading width.
+                        </p>
+                      </CardContent>
+                    </Card>
+                  </div>
+                </div>
+              </div>
+            </Example>
+
+            <BeforeAfter
+              title="Common Mistake: No Width Constraint"
+              description="Content should not span full viewport width"
+              before={{
+                caption: "No max-width, hard to read on wide screens",
+                content: (
+                  <div className="w-full space-y-4 bg-background p-4 rounded">
+                    <h3 className="font-semibold">Full Width Content</h3>
+                    <p className="text-sm text-muted-foreground">
+                      This text spans the entire width, making it hard to read on
+                      large screens. Lines become too long.
+                    </p>
+                  </div>
+                ),
+              }}
+              after={{
+                caption: "Constrained with max-w for better readability",
+                content: (
+                  <div className="max-w-2xl mx-auto space-y-4 bg-background p-4 rounded">
+                    <h3 className="font-semibold">Constrained Content</h3>
+                    <p className="text-sm text-muted-foreground">
+                      This text has a max-width, creating comfortable line lengths
+                      for reading.
+                    </p>
+                  </div>
+                ),
+              }}
+            />
+          </ExampleSection>
+
+          {/* 2. Dashboard Grid */}
+          <ExampleSection
+            id="dashboard-grid"
+            title="2. Dashboard Grid"
+            description="Responsive card grid for metrics and data"
+          >
+            <Example
+              title="Responsive Grid Pattern"
+              description="1 → 2 → 3 columns progression with grid"
+              code={`<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
+  {items.map(item => (
+    <Card key={item.id}>
+      <CardHeader>
+        <CardTitle>{item.title}</CardTitle>
+      </CardHeader>
+      <CardContent>{item.content}</CardContent>
+    </Card>
+  ))}
+</div>`}
+            >
+              <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
+                {[1, 2, 3, 4, 5, 6].map((i) => (
+                  <Card key={i}>
+                    <CardHeader className="pb-2">
+                      <CardTitle className="text-sm font-medium">
+                        Metric {i}
+                      </CardTitle>
+                    </CardHeader>
+                    <CardContent>
+                      <div className="text-2xl font-bold">
+                        {(Math.random() * 1000).toFixed(0)}
+                      </div>
+                      <p className="text-xs text-muted-foreground mt-1">
+                        +{(Math.random() * 20).toFixed(1)}% from last month
+                      </p>
+                    </CardContent>
+                  </Card>
+                ))}
+              </div>
+            </Example>
+
+            <BeforeAfter
+              title="Grid vs Flex for Equal Columns"
+              description="Use Grid for equal-width columns, not Flex"
+              before={{
+                caption: "flex with flex-1 - uneven wrapping",
+                content: (
+                  <div className="flex flex-wrap gap-4">
+                    <div className="flex-1 min-w-[200px] rounded border bg-background p-4">
+                      <div className="text-xs">flex-1</div>
+                    </div>
+                    <div className="flex-1 min-w-[200px] rounded border bg-background p-4">
+                      <div className="text-xs">flex-1</div>
+                    </div>
+                    <div className="flex-1 min-w-[200px] rounded border bg-background p-4">
+                      <div className="text-xs">flex-1 (odd one out)</div>
+                    </div>
+                  </div>
+                ),
+              }}
+              after={{
+                caption: "grid with grid-cols - consistent sizing",
+                content: (
+                  <div className="grid grid-cols-1 sm:grid-cols-3 gap-4">
+                    <div className="rounded border bg-background p-4">
+                      <div className="text-xs">grid-cols</div>
+                    </div>
+                    <div className="rounded border bg-background p-4">
+                      <div className="text-xs">grid-cols</div>
+                    </div>
+                    <div className="rounded border bg-background p-4">
+                      <div className="text-xs">grid-cols (perfect)</div>
+                    </div>
+                  </div>
+                ),
+              }}
+            />
+          </ExampleSection>
+
+          {/* 3. Form Layout */}
+          <ExampleSection
+            id="form-layout"
+            title="3. Form Layout"
+            description="Centered form with appropriate max-width"
+          >
+            <Example
+              title="Centered Form Pattern"
+              description="Form constrained to max-w-md"
+              code={`<div className="container mx-auto px-4 py-8">
+  <Card className="max-w-md mx-auto">
+    <CardHeader>
+      <CardTitle>Login</CardTitle>
+      <CardDescription>Enter your credentials</CardDescription>
+    </CardHeader>
+    <CardContent>
+      <form className="space-y-4">
+        {/* Form fields */}
+      </form>
+    </CardContent>
+  </Card>
+</div>`}
+            >
+              <div className="container mx-auto px-4 py-8">
+                <Card className="max-w-md mx-auto">
+                  <CardHeader>
+                    <CardTitle>Login</CardTitle>
+                    <CardDescription>
+                      Enter your credentials to continue
+                    </CardDescription>
+                  </CardHeader>
+                  <CardContent>
+                    <form className="space-y-4">
+                      <div className="space-y-2">
+                        <div className="text-sm font-medium">Email</div>
+                        <div className="h-10 rounded-md border bg-background"></div>
+                      </div>
+                      <div className="space-y-2">
+                        <div className="text-sm font-medium">Password</div>
+                        <div className="h-10 rounded-md border bg-background"></div>
+                      </div>
+                      <Button className="w-full">Sign In</Button>
+                    </form>
+                  </CardContent>
+                </Card>
+              </div>
+            </Example>
+          </ExampleSection>
+
+          {/* 4. Sidebar Layout */}
+          <ExampleSection
+            id="sidebar-layout"
+            title="4. Sidebar Layout"
+            description="Two-column layout with fixed sidebar"
+          >
+            <Example
+              title="Sidebar + Main Content"
+              description="Grid with fixed sidebar width"
+              code={`<div className="grid lg:grid-cols-[240px_1fr] gap-6">
+  {/* Sidebar */}
+  <aside className="space-y-4">
+    <Card>
+      <CardHeader>
+        <CardTitle>Navigation</CardTitle>
+      </CardHeader>
+      <CardContent>{/* Nav items */}</CardContent>
+    </Card>
+  </aside>
+
+  {/* Main Content */}
+  <main className="space-y-4">
+    <Card>{/* Content */}</Card>
+  </main>
+</div>`}
+            >
+              <div className="grid lg:grid-cols-[240px_1fr] gap-6">
+                {/* Sidebar */}
+                <aside className="space-y-4">
+                  <Card>
+                    <CardHeader>
+                      <CardTitle className="text-base">Navigation</CardTitle>
+                    </CardHeader>
+                    <CardContent className="space-y-2">
+                      {['Dashboard', 'Settings', 'Profile'].map((item) => (
+                        <div
+                          key={item}
+                          className="rounded-md bg-muted px-3 py-2 text-sm"
+                        >
+                          {item}
+                        </div>
+                      ))}
+                    </CardContent>
+                  </Card>
+                </aside>
+
+                {/* Main Content */}
+                <main className="space-y-4">
+                  <Card>
+                    <CardHeader>
+                      <CardTitle>Main Content</CardTitle>
+                      <CardDescription>
+                        Fixed 240px sidebar, fluid main area
+                      </CardDescription>
+                    </CardHeader>
+                    <CardContent>
+                      <p className="text-sm text-muted-foreground">
+                        The sidebar remains 240px wide while the main content area
+                        flexes to fill remaining space.
+                      </p>
+                    </CardContent>
+                  </Card>
+                </main>
+              </div>
+            </Example>
+          </ExampleSection>
+
+          {/* 5. Centered Content */}
+          <ExampleSection
+            id="centered-content"
+            title="5. Centered Content"
+            description="Vertically and horizontally centered layouts"
+          >
+            <Example
+              title="Center with Flexbox"
+              description="Full-height centered content"
+              code={`<div className="flex min-h-screen items-center justify-center">
+  <Card className="max-w-md w-full">
+    <CardHeader>
+      <CardTitle>Centered Card</CardTitle>
+    </CardHeader>
+    <CardContent>
+      <p>Content perfectly centered on screen.</p>
+    </CardContent>
+  </Card>
+</div>`}
+            >
+              <div className="flex min-h-[400px] items-center justify-center rounded-lg border bg-muted/30 p-4">
+                <Card className="max-w-sm w-full">
+                  <CardHeader>
+                    <CardTitle>Centered Card</CardTitle>
+                    <CardDescription>
+                      Centered vertically and horizontally
+                    </CardDescription>
+                  </CardHeader>
+                  <CardContent>
+                    <p className="text-sm text-muted-foreground">
+                      Perfect for login screens, error pages, and loading states.
+                    </p>
+                  </CardContent>
+                </Card>
+              </div>
+            </Example>
+          </ExampleSection>
+
+          {/* Decision Tree */}
+          <ExampleSection
+            id="decision-tree"
+            title="Decision Tree: Grid vs Flex"
+            description="When to use each layout method"
+          >
+            <Card>
+              <CardHeader>
+                <div className="flex items-center gap-2">
+                  <Grid3x3 className="h-5 w-5 text-primary" />
+                  <CardTitle>Grid vs Flex Quick Guide</CardTitle>
+                </div>
+              </CardHeader>
+              <CardContent className="space-y-6">
+                <div className="space-y-4">
+                  <div className="space-y-2">
+                    <div className="flex items-center gap-2">
+                      <Badge variant="default">Use Grid</Badge>
+                      <span className="text-sm font-medium">When you need...</span>
+                    </div>
+                    <ul className="ml-6 space-y-1 text-sm text-muted-foreground list-disc">
+                      <li>Equal-width columns (dashboard cards)</li>
+                      <li>2D layout (rows AND columns)</li>
+                      <li>Consistent grid structure</li>
+                      <li>Auto-fill/auto-fit responsive grids</li>
+                    </ul>
+                    <div className="rounded-lg border bg-muted/30 p-3 font-mono text-xs">
+                      grid grid-cols-3 gap-6
+                    </div>
+                  </div>
+
+                  <div className="space-y-2">
+                    <div className="flex items-center gap-2">
+                      <Badge variant="secondary">Use Flex</Badge>
+                      <span className="text-sm font-medium">When you need...</span>
+                    </div>
+                    <ul className="ml-6 space-y-1 text-sm text-muted-foreground list-disc">
+                      <li>Variable-width items (buttons, tags)</li>
+                      <li>1D layout (row OR column)</li>
+                      <li>Center alignment</li>
+                      <li>Space-between/around distribution</li>
+                    </ul>
+                    <div className="rounded-lg border bg-muted/30 p-3 font-mono text-xs">
+                      flex gap-4 items-center
+                    </div>
+                  </div>
+                </div>
+              </CardContent>
+            </Card>
+          </ExampleSection>
+
+          {/* Responsive Patterns */}
+          <ExampleSection
+            id="responsive"
+            title="Responsive Patterns"
+            description="Mobile-first breakpoint strategies"
+          >
+            <div className="grid gap-6 lg:grid-cols-2">
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">1 → 2 → 3 Progression</CardTitle>
+                  <CardDescription>Most common pattern</CardDescription>
+                </CardHeader>
+                <CardContent>
+                  <code className="text-xs">
+                    grid-cols-1 md:grid-cols-2 lg:grid-cols-3
+                  </code>
+                  <p className="mt-2 text-sm text-muted-foreground">
+                    Mobile: 1 column
+                    <br />
+                    Tablet: 2 columns
+                    <br />
+                    Desktop: 3 columns
+                  </p>
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">1 → 2 → 4 Progression</CardTitle>
+                  <CardDescription>For smaller cards</CardDescription>
+                </CardHeader>
+                <CardContent>
+                  <code className="text-xs">
+                    grid-cols-1 md:grid-cols-2 lg:grid-cols-4
+                  </code>
+                  <p className="mt-2 text-sm text-muted-foreground">
+                    Mobile: 1 column
+                    <br />
+                    Tablet: 2 columns
+                    <br />
+                    Desktop: 4 columns
+                  </p>
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">Stack → Row</CardTitle>
+                  <CardDescription>Form buttons, toolbars</CardDescription>
+                </CardHeader>
+                <CardContent>
+                  <code className="text-xs">flex flex-col sm:flex-row</code>
+                  <p className="mt-2 text-sm text-muted-foreground">
+                    Mobile: Stacked vertically
+                    <br />
+                    Tablet+: Horizontal row
+                  </p>
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">Hide Sidebar</CardTitle>
+                  <CardDescription>Mobile navigation</CardDescription>
+                </CardHeader>
+                <CardContent>
+                  <code className="text-xs">
+                    hidden lg:block
+                  </code>
+                  <p className="mt-2 text-sm text-muted-foreground">
+                    Mobile: Hidden (use menu)
+                    <br />
+                    Desktop: Visible sidebar
+                  </p>
+                </CardContent>
+              </Card>
+            </div>
+          </ExampleSection>
+        </div>
+      </main>
+
+      {/* Footer */}
+      <footer className="mt-16 border-t py-6">
+        <div className="container mx-auto px-4 text-center">
+          <p className="text-sm text-muted-foreground">
+            Learn more:{' '}
+            <a
+              href="/docs/design-system/03-layouts.md"
+              target="_blank"
+              rel="noopener noreferrer"
+              className="font-medium hover:text-foreground"
+            >
+              Layout Documentation
+            </a>
+          </p>
+        </div>
+      </footer>
+    </div>
+  );
+}
diff --git a/frontend/src/app/dev/page.tsx b/frontend/src/app/dev/page.tsx
new file mode 100644
index 0000000..0480d5a
--- /dev/null
+++ b/frontend/src/app/dev/page.tsx
@@ -0,0 +1,309 @@
+/**
+ * Design System Hub
+ * Central landing page for all interactive design system demonstrations
+ * Access: /dev
+ */
+
+import type { Metadata } from 'next';
+import Link from 'next/link';
+import {
+  Palette,
+  Layout,
+  Ruler,
+  FileText,
+  BookOpen,
+  ArrowRight,
+  Sparkles,
+} from 'lucide-react';
+import { Button } from '@/components/ui/button';
+import {
+  Card,
+  CardContent,
+  CardDescription,
+  CardHeader,
+  CardTitle,
+} from '@/components/ui/card';
+import { Badge } from '@/components/ui/badge';
+import { Separator } from '@/components/ui/separator';
+
+export const metadata: Metadata = {
+  title: 'Design System Hub | Dev',
+  description: 'Interactive demonstrations and documentation for the FastNext design system',
+};
+
+const demoPages = [
+  {
+    title: 'Components',
+    description: 'Explore all shadcn/ui components with live examples and copy-paste code',
+    href: '/dev/components',
+    icon: Palette,
+    status: 'enhanced' as const,
+    highlights: ['All variants', 'Interactive demos', 'Copy-paste code'],
+  },
+  {
+    title: 'Layouts',
+    description: 'Essential layout patterns for pages, dashboards, forms, and content',
+    href: '/dev/layouts',
+    icon: Layout,
+    status: 'new' as const,
+    highlights: ['Grid vs Flex', 'Responsive patterns', 'Before/after examples'],
+  },
+  {
+    title: 'Spacing',
+    description: 'Visual demonstrations of spacing philosophy and best practices',
+    href: '/dev/spacing',
+    icon: Ruler,
+    status: 'new' as const,
+    highlights: ['Parent-controlled', 'Gap vs Space-y', 'Anti-patterns'],
+  },
+  {
+    title: 'Forms',
+    description: 'Complete form implementations with validation and error handling',
+    href: '/dev/forms',
+    icon: FileText,
+    status: 'new' as const,
+    highlights: ['react-hook-form', 'Zod validation', 'Loading states'],
+  },
+];
+
+const documentationLinks = [
+  {
+    title: 'Quick Start',
+    description: '5-minute crash course',
+    href: '/docs/design-system/00-quick-start.md',
+  },
+  {
+    title: 'Complete Documentation',
+    description: 'Full design system guide',
+    href: '/docs/design-system/README.md',
+  },
+  {
+    title: 'AI Guidelines',
+    description: 'Rules for AI code generation',
+    href: '/docs/design-system/08-ai-guidelines.md',
+  },
+  {
+    title: 'Quick Reference',
+    description: 'Cheat sheet for lookups',
+    href: '/docs/design-system/99-reference.md',
+  },
+];
+
+export default function DesignSystemHub() {
+  return (
+    <div className="min-h-screen bg-background">
+      {/* Header */}
+      <header className="border-b bg-background/95 backdrop-blur supports-[backdrop-filter]:bg-background/60">
+        <div className="container mx-auto px-4 py-8">
+          <div className="space-y-4">
+            <div className="flex items-center gap-2">
+              <Sparkles className="h-8 w-8 text-primary" />
+              <h1 className="text-4xl font-bold tracking-tight">
+                Design System Hub
+              </h1>
+            </div>
+            <p className="text-lg text-muted-foreground max-w-2xl">
+              Interactive demonstrations, live examples, and copy-paste code for
+              the FastNext design system. Built with shadcn/ui + Tailwind CSS 4.
+            </p>
+          </div>
+        </div>
+      </header>
+
+      {/* Main Content */}
+      <main className="container mx-auto px-4 py-12">
+        <div className="space-y-12">
+          {/* Demo Pages Grid */}
+          <section className="space-y-6">
+            <div>
+              <h2 className="text-2xl font-semibold tracking-tight">
+                Interactive Demonstrations
+              </h2>
+              <p className="text-sm text-muted-foreground mt-2">
+                Explore live examples with copy-paste code snippets
+              </p>
+            </div>
+
+            <div className="grid gap-6 md:grid-cols-2">
+              {demoPages.map((page) => {
+                const Icon = page.icon;
+                return (
+                  <Card
+                    key={page.href}
+                    className="group relative overflow-hidden transition-all hover:border-primary/50"
+                  >
+                    <CardHeader>
+                      <div className="flex items-start justify-between">
+                        <div className="rounded-lg bg-primary/10 p-2">
+                          <Icon className="h-6 w-6 text-primary" />
+                        </div>
+                        {page.status === 'new' && (
+                          <Badge variant="default" className="gap-1">
+                            <Sparkles className="h-3 w-3" />
+                            New
+                          </Badge>
+                        )}
+                        {page.status === 'enhanced' && (
+                          <Badge variant="secondary">Enhanced</Badge>
+                        )}
+                      </div>
+                      <CardTitle className="mt-4">{page.title}</CardTitle>
+                      <CardDescription>{page.description}</CardDescription>
+                    </CardHeader>
+                    <CardContent className="space-y-4">
+                      {/* Highlights */}
+                      <div className="flex flex-wrap gap-2">
+                        {page.highlights.map((highlight) => (
+                          <Badge key={highlight} variant="outline" className="text-xs">
+                            {highlight}
+                          </Badge>
+                        ))}
+                      </div>
+
+                      {/* CTA */}
+                      <Link href={page.href} className="block">
+                        <Button className="w-full gap-2 group-hover:bg-primary/90">
+                          Explore {page.title}
+                          <ArrowRight className="h-4 w-4 transition-transform group-hover:translate-x-1" />
+                        </Button>
+                      </Link>
+                    </CardContent>
+                  </Card>
+                );
+              })}
+            </div>
+          </section>
+
+          <Separator />
+
+          {/* Documentation Links */}
+          <section className="space-y-6">
+            <div>
+              <h2 className="text-2xl font-semibold tracking-tight flex items-center gap-2">
+                <BookOpen className="h-6 w-6" />
+                Documentation
+              </h2>
+              <p className="text-sm text-muted-foreground mt-2">
+                Comprehensive guides and reference materials
+              </p>
+            </div>
+
+            <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-4">
+              {documentationLinks.map((link) => (
+                <a
+                  key={link.href}
+                  href={link.href}
+                  target="_blank"
+                  rel="noopener noreferrer"
+                  className="group"
+                >
+                  <Card className="h-full transition-all hover:border-primary/50 hover:bg-accent/50">
+                    <CardHeader className="space-y-1">
+                      <CardTitle className="text-base group-hover:text-primary transition-colors">
+                        {link.title}
+                      </CardTitle>
+                      <CardDescription className="text-xs">
+                        {link.description}
+                      </CardDescription>
+                    </CardHeader>
+                  </Card>
+                </a>
+              ))}
+            </div>
+          </section>
+
+          <Separator />
+
+          {/* Key Features */}
+          <section className="space-y-6">
+            <h2 className="text-2xl font-semibold tracking-tight">
+              Key Features
+            </h2>
+
+            <div className="grid gap-6 sm:grid-cols-2 lg:grid-cols-3">
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">🎨 OKLCH Color System</CardTitle>
+                </CardHeader>
+                <CardContent className="text-sm text-muted-foreground">
+                  Perceptually uniform colors with semantic tokens for consistent theming
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">📏 Parent-Controlled Spacing</CardTitle>
+                </CardHeader>
+                <CardContent className="text-sm text-muted-foreground">
+                  Consistent spacing philosophy using gap and space-y utilities
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">♿ WCAG AA Compliant</CardTitle>
+                </CardHeader>
+                <CardContent className="text-sm text-muted-foreground">
+                  Full accessibility support with keyboard navigation and screen readers
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">📱 Mobile-First Responsive</CardTitle>
+                </CardHeader>
+                <CardContent className="text-sm text-muted-foreground">
+                  Tailwind breakpoints with progressive enhancement
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">🤖 AI-Optimized</CardTitle>
+                </CardHeader>
+                <CardContent className="text-sm text-muted-foreground">
+                  Dedicated guidelines for Claude Code, Cursor, and GitHub Copilot
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">🚀 Production-Ready</CardTitle>
+                </CardHeader>
+                <CardContent className="text-sm text-muted-foreground">
+                  Battle-tested patterns with real-world examples
+                </CardContent>
+              </Card>
+            </div>
+          </section>
+        </div>
+      </main>
+
+      {/* Footer */}
+      <footer className="mt-16 border-t py-8">
+        <div className="container mx-auto px-4 text-center text-sm text-muted-foreground">
+          <p>
+            FastNext Design System • Built with{' '}
+            <a
+              href="https://ui.shadcn.com"
+              target="_blank"
+              rel="noopener noreferrer"
+              className="font-medium hover:text-foreground"
+            >
+              shadcn/ui
+            </a>
+            {' + '}
+            <a
+              href="https://tailwindcss.com"
+              target="_blank"
+              rel="noopener noreferrer"
+              className="font-medium hover:text-foreground"
+            >
+              Tailwind CSS 4
+            </a>
+          </p>
+        </div>
+      </footer>
+    </div>
+  );
+}
diff --git a/frontend/src/app/dev/spacing/page.tsx b/frontend/src/app/dev/spacing/page.tsx
new file mode 100644
index 0000000..7f808fa
--- /dev/null
+++ b/frontend/src/app/dev/spacing/page.tsx
@@ -0,0 +1,522 @@
+/**
+ * Spacing Patterns Demo
+ * Interactive demonstrations of spacing philosophy and best practices
+ * Access: /dev/spacing
+ */
+
+import type { Metadata } from 'next';
+import Link from 'next/link';
+import { ArrowLeft, Ruler } from 'lucide-react';
+import { Button } from '@/components/ui/button';
+import {
+  Card,
+  CardContent,
+  CardDescription,
+  CardHeader,
+  CardTitle,
+} from '@/components/ui/card';
+import { Badge } from '@/components/ui/badge';
+import { Example, ExampleSection } from '@/components/dev/Example';
+import { BeforeAfter } from '@/components/dev/BeforeAfter';
+
+export const metadata: Metadata = {
+  title: 'Spacing Patterns | Dev',
+  description: 'Parent-controlled spacing philosophy and visual demonstrations',
+};
+
+export default function SpacingPage() {
+  return (
+    <div className="min-h-screen bg-background">
+      {/* Header */}
+      <header className="sticky top-0 z-50 w-full border-b bg-background/95 backdrop-blur supports-[backdrop-filter]:bg-background/60">
+        <div className="container mx-auto flex h-16 items-center gap-4 px-4">
+          <Link href="/dev">
+            <Button variant="ghost" size="icon" aria-label="Back to hub">
+              <ArrowLeft className="h-5 w-5" />
+            </Button>
+          </Link>
+          <div>
+            <h1 className="text-xl font-bold">Spacing Patterns</h1>
+            <p className="text-sm text-muted-foreground">
+              Parent-controlled spacing philosophy
+            </p>
+          </div>
+        </div>
+      </header>
+
+      {/* Content */}
+      <main className="container mx-auto px-4 py-8">
+        <div className="space-y-12">
+          {/* Introduction */}
+          <div className="max-w-3xl space-y-4">
+            <p className="text-muted-foreground">
+              The Golden Rule: <strong>Parents control spacing, not children.</strong>{' '}
+              Use gap, space-y, and space-x utilities on the parent container. Avoid
+              margins on children except for exceptions.
+            </p>
+            <div className="flex flex-wrap gap-2">
+              <Badge variant="outline">gap</Badge>
+              <Badge variant="outline">space-y</Badge>
+              <Badge variant="outline">space-x</Badge>
+              <Badge variant="destructive">avoid margin</Badge>
+            </div>
+          </div>
+
+          {/* Spacing Scale */}
+          <ExampleSection
+            id="spacing-scale"
+            title="Spacing Scale"
+            description="Multiples of 4px (Tailwind's base unit)"
+          >
+            <Card>
+              <CardHeader>
+                <CardTitle>Common Spacing Values</CardTitle>
+                <CardDescription>
+                  Use consistent spacing values from the scale
+                </CardDescription>
+              </CardHeader>
+              <CardContent>
+                <div className="space-y-4">
+                  {[
+                    { class: '2', px: '8px', rem: '0.5rem', use: 'Tight (label → input)' },
+                    { class: '4', px: '16px', rem: '1rem', use: 'Standard (form fields)' },
+                    { class: '6', px: '24px', rem: '1.5rem', use: 'Section spacing' },
+                    { class: '8', px: '32px', rem: '2rem', use: 'Large gaps' },
+                    { class: '12', px: '48px', rem: '3rem', use: 'Section dividers' },
+                  ].map((item) => (
+                    <div
+                      key={item.class}
+                      className="grid grid-cols-[80px_80px_100px_1fr] items-center gap-4"
+                    >
+                      <code className="text-sm font-mono">gap-{item.class}</code>
+                      <span className="text-sm text-muted-foreground">{item.px}</span>
+                      <span className="text-sm text-muted-foreground">{item.rem}</span>
+                      <span className="text-sm">{item.use}</span>
+                      <div className="col-span-4">
+                        <div
+                          className="h-2 rounded bg-primary"
+                          style={{ width: item.px }}
+                        ></div>
+                      </div>
+                    </div>
+                  ))}
+                </div>
+              </CardContent>
+            </Card>
+          </ExampleSection>
+
+          {/* Gap for Flex/Grid */}
+          <ExampleSection
+            id="gap"
+            title="Gap: For Flex and Grid"
+            description="Preferred method for spacing flex and grid children"
+          >
+            <Example
+              title="Gap with Flex"
+              description="Horizontal and vertical spacing"
+              code={`{/* Horizontal */}
+<div className="flex gap-4">
+  <Button>Cancel</Button>
+  <Button>Save</Button>
+</div>
+
+{/* Vertical */}
+<div className="flex flex-col gap-4">
+  <div>Item 1</div>
+  <div>Item 2</div>
+</div>
+
+{/* Grid */}
+<div className="grid grid-cols-3 gap-6">
+  {/* Cards */}
+</div>`}
+            >
+              <div className="space-y-6">
+                {/* Horizontal */}
+                <div>
+                  <p className="text-sm font-medium mb-2">Horizontal (gap-4)</p>
+                  <div className="flex gap-4">
+                    <Button variant="outline">Cancel</Button>
+                    <Button>Save</Button>
+                  </div>
+                </div>
+
+                {/* Vertical */}
+                <div>
+                  <p className="text-sm font-medium mb-2">Vertical (gap-4)</p>
+                  <div className="flex flex-col gap-4">
+                    <div className="rounded-lg border bg-muted p-3 text-sm">Item 1</div>
+                    <div className="rounded-lg border bg-muted p-3 text-sm">Item 2</div>
+                    <div className="rounded-lg border bg-muted p-3 text-sm">Item 3</div>
+                  </div>
+                </div>
+
+                {/* Grid */}
+                <div>
+                  <p className="text-sm font-medium mb-2">Grid (gap-6)</p>
+                  <div className="grid grid-cols-3 gap-6">
+                    {[1, 2, 3].map((i) => (
+                      <div
+                        key={i}
+                        className="rounded-lg border bg-muted p-3 text-center text-sm"
+                      >
+                        Card {i}
+                      </div>
+                    ))}
+                  </div>
+                </div>
+              </div>
+            </Example>
+          </ExampleSection>
+
+          {/* Space-y for Stacks */}
+          <ExampleSection
+            id="space-y"
+            title="Space-y: For Vertical Stacks"
+            description="Simple vertical spacing without flex/grid"
+          >
+            <Example
+              title="Space-y Pattern"
+              description="Adds margin-top to all children except first"
+              code={`<div className="space-y-4">
+  <div>First item (no margin)</div>
+  <div>Second item (mt-4)</div>
+  <div>Third item (mt-4)</div>
+</div>
+
+{/* Form example */}
+<form className="space-y-4">
+  <div className="space-y-2">
+    <Label>Email</Label>
+    <Input />
+  </div>
+  <div className="space-y-2">
+    <Label>Password</Label>
+    <Input />
+  </div>
+  <Button>Submit</Button>
+</form>`}
+            >
+              <div className="max-w-md space-y-6">
+                {/* Visual demo */}
+                <div>
+                  <p className="text-sm font-medium mb-4">Visual Demo (space-y-4)</p>
+                  <div className="space-y-4">
+                    <div className="rounded-lg border bg-muted p-3 text-sm">
+                      First item (no margin)
+                    </div>
+                    <div className="rounded-lg border bg-muted p-3 text-sm">
+                      Second item (mt-4)
+                    </div>
+                    <div className="rounded-lg border bg-muted p-3 text-sm">
+                      Third item (mt-4)
+                    </div>
+                  </div>
+                </div>
+
+                {/* Form example */}
+                <div>
+                  <p className="text-sm font-medium mb-4">Form Example (space-y-4)</p>
+                  <div className="space-y-4 rounded-lg border p-4">
+                    <div className="space-y-2">
+                      <div className="text-sm font-medium">Email</div>
+                      <div className="h-10 rounded-md border bg-background"></div>
+                    </div>
+                    <div className="space-y-2">
+                      <div className="text-sm font-medium">Password</div>
+                      <div className="h-10 rounded-md border bg-background"></div>
+                    </div>
+                    <Button className="w-full">Submit</Button>
+                  </div>
+                </div>
+              </div>
+            </Example>
+          </ExampleSection>
+
+          {/* Anti-pattern: Child Margins */}
+          <ExampleSection
+            id="anti-patterns"
+            title="Anti-patterns to Avoid"
+            description="Common spacing mistakes"
+          >
+            <BeforeAfter
+              title="Don't Let Children Control Spacing"
+              description="Parent should control spacing, not children"
+              before={{
+                caption: "Children control their own spacing with mt-4",
+                content: (
+                  <div className="space-y-2 rounded-lg border p-4">
+                    <div className="rounded bg-muted p-2 text-xs">
+                      <div>Child 1</div>
+                      <code className="text-[10px] text-destructive">no margin</code>
+                    </div>
+                    <div className="rounded bg-muted p-2 text-xs">
+                      <div>Child 2</div>
+                      <code className="text-[10px] text-destructive">mt-4</code>
+                    </div>
+                    <div className="rounded bg-muted p-2 text-xs">
+                      <div>Child 3</div>
+                      <code className="text-[10px] text-destructive">mt-4</code>
+                    </div>
+                  </div>
+                ),
+              }}
+              after={{
+                caption: "Parent controls spacing with space-y-4",
+                content: (
+                  <div className="space-y-4 rounded-lg border p-4">
+                    <div className="rounded bg-muted p-2 text-xs">
+                      <div>Child 1</div>
+                      <code className="text-[10px] text-green-600">
+                        parent uses space-y-4
+                      </code>
+                    </div>
+                    <div className="rounded bg-muted p-2 text-xs">
+                      <div>Child 2</div>
+                      <code className="text-[10px] text-green-600">clean, no margin</code>
+                    </div>
+                    <div className="rounded bg-muted p-2 text-xs">
+                      <div>Child 3</div>
+                      <code className="text-[10px] text-green-600">clean, no margin</code>
+                    </div>
+                  </div>
+                ),
+              }}
+            />
+
+            <BeforeAfter
+              title="Use Gap, Not Margin for Buttons"
+              description="Button groups should use gap, not margins"
+              before={{
+                caption: "Margin on children - harder to maintain",
+                content: (
+                  <div className="flex rounded-lg border p-4">
+                    <Button variant="outline" size="sm">
+                      Cancel
+                    </Button>
+                    <Button size="sm" className="ml-4">
+                      Save
+                    </Button>
+                  </div>
+                ),
+              }}
+              after={{
+                caption: "Gap on parent - clean and flexible",
+                content: (
+                  <div className="flex gap-4 rounded-lg border p-4">
+                    <Button variant="outline" size="sm">
+                      Cancel
+                    </Button>
+                    <Button size="sm">Save</Button>
+                  </div>
+                ),
+              }}
+            />
+          </ExampleSection>
+
+          {/* Decision Tree */}
+          <ExampleSection
+            id="decision-tree"
+            title="Decision Tree: Which Spacing Method?"
+            description="Choose the right spacing utility"
+          >
+            <Card>
+              <CardHeader>
+                <div className="flex items-center gap-2">
+                  <Ruler className="h-5 w-5 text-primary" />
+                  <CardTitle>Spacing Decision Tree</CardTitle>
+                </div>
+              </CardHeader>
+              <CardContent className="space-y-6">
+                <div className="space-y-4">
+                  {/* Gap */}
+                  <div className="space-y-2">
+                    <div className="flex items-center gap-2">
+                      <Badge variant="default">Use gap</Badge>
+                      <span className="text-sm font-medium">When...</span>
+                    </div>
+                    <ul className="ml-6 space-y-1 text-sm text-muted-foreground list-disc">
+                      <li>Parent is flex or grid</li>
+                      <li>All children need equal spacing</li>
+                      <li>Responsive spacing (gap-4 md:gap-6)</li>
+                    </ul>
+                    <div className="rounded-lg border bg-muted/30 p-3 font-mono text-xs">
+                      flex gap-4
+                      <br />
+                      grid grid-cols-3 gap-6
+                    </div>
+                  </div>
+
+                  {/* Space-y */}
+                  <div className="space-y-2">
+                    <div className="flex items-center gap-2">
+                      <Badge variant="secondary">Use space-y</Badge>
+                      <span className="text-sm font-medium">When...</span>
+                    </div>
+                    <ul className="ml-6 space-y-1 text-sm text-muted-foreground list-disc">
+                      <li>Vertical stack without flex/grid</li>
+                      <li>Form fields</li>
+                      <li>Content sections</li>
+                    </ul>
+                    <div className="rounded-lg border bg-muted/30 p-3 font-mono text-xs">
+                      space-y-4
+                      <br />
+                      space-y-6
+                    </div>
+                  </div>
+
+                  {/* Margin */}
+                  <div className="space-y-2">
+                    <div className="flex items-center gap-2">
+                      <Badge variant="destructive">Use margin</Badge>
+                      <span className="text-sm font-medium">Only when...</span>
+                    </div>
+                    <ul className="ml-6 space-y-1 text-sm text-muted-foreground list-disc">
+                      <li>Exception case (one child needs different spacing)</li>
+                      <li>Negative margin for overlap effects</li>
+                      <li>Can't modify parent (external component)</li>
+                    </ul>
+                    <div className="rounded-lg border bg-muted/30 p-3 font-mono text-xs">
+                      mt-8 {/* exception */}
+                      <br />
+                      -mt-4 {/* overlap */}
+                    </div>
+                  </div>
+
+                  {/* Padding */}
+                  <div className="space-y-2">
+                    <div className="flex items-center gap-2">
+                      <Badge variant="outline">Use padding</Badge>
+                      <span className="text-sm font-medium">When...</span>
+                    </div>
+                    <ul className="ml-6 space-y-1 text-sm text-muted-foreground list-disc">
+                      <li>Internal spacing within a component</li>
+                      <li>Card/container padding</li>
+                      <li>Button padding</li>
+                    </ul>
+                    <div className="rounded-lg border bg-muted/30 p-3 font-mono text-xs">
+                      p-4 {/* all sides */}
+                      <br />
+                      px-4 py-2 {/* horizontal & vertical */}
+                    </div>
+                  </div>
+                </div>
+              </CardContent>
+            </Card>
+          </ExampleSection>
+
+          {/* Common Patterns */}
+          <ExampleSection
+            id="common-patterns"
+            title="Common Patterns"
+            description="Real-world spacing examples"
+          >
+            <div className="grid gap-6 lg:grid-cols-2">
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">Form Fields</CardTitle>
+                  <CardDescription>Parent: space-y-4, Field: space-y-2</CardDescription>
+                </CardHeader>
+                <CardContent>
+                  <code className="text-xs block mb-3">
+                    {`<form className="space-y-4">
+  <div className="space-y-2">
+    <Label>Email</Label>
+    <Input />
+  </div>
+</form>`}
+                  </code>
+                  <div className="space-y-4 rounded-lg border bg-muted/30 p-4">
+                    <div className="space-y-2">
+                      <div className="text-xs font-medium">Email</div>
+                      <div className="h-8 rounded border bg-background"></div>
+                    </div>
+                    <div className="space-y-2">
+                      <div className="text-xs font-medium">Password</div>
+                      <div className="h-8 rounded border bg-background"></div>
+                    </div>
+                  </div>
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">Button Group</CardTitle>
+                  <CardDescription>Use flex gap-4</CardDescription>
+                </CardHeader>
+                <CardContent>
+                  <code className="text-xs block mb-3">
+                    {`<div className="flex gap-4">
+  <Button variant="outline">Cancel</Button>
+  <Button>Save</Button>
+</div>`}
+                  </code>
+                  <div className="flex gap-4 rounded-lg border bg-muted/30 p-4">
+                    <Button variant="outline" size="sm">
+                      Cancel
+                    </Button>
+                    <Button size="sm">Save</Button>
+                  </div>
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">Card Grid</CardTitle>
+                  <CardDescription>Use grid with gap-6</CardDescription>
+                </CardHeader>
+                <CardContent>
+                  <code className="text-xs block mb-3">
+                    {`<div className="grid grid-cols-2 gap-6">
+  <Card>...</Card>
+</div>`}
+                  </code>
+                  <div className="grid grid-cols-2 gap-4 rounded-lg border bg-muted/30 p-4">
+                    <div className="h-16 rounded border bg-background"></div>
+                    <div className="h-16 rounded border bg-background"></div>
+                  </div>
+                </CardContent>
+              </Card>
+
+              <Card>
+                <CardHeader>
+                  <CardTitle className="text-base">Content Stack</CardTitle>
+                  <CardDescription>Use space-y-6 for sections</CardDescription>
+                </CardHeader>
+                <CardContent>
+                  <code className="text-xs block mb-3">
+                    {`<div className="space-y-6">
+  <section>...</section>
+  <section>...</section>
+</div>`}
+                  </code>
+                  <div className="space-y-4 rounded-lg border bg-muted/30 p-4">
+                    <div className="h-12 rounded border bg-background"></div>
+                    <div className="h-12 rounded border bg-background"></div>
+                  </div>
+                </CardContent>
+              </Card>
+            </div>
+          </ExampleSection>
+        </div>
+      </main>
+
+      {/* Footer */}
+      <footer className="mt-16 border-t py-6">
+        <div className="container mx-auto px-4 text-center">
+          <p className="text-sm text-muted-foreground">
+            Learn more:{' '}
+            <a
+              href="/docs/design-system/04-spacing-philosophy.md"
+              target="_blank"
+              rel="noopener noreferrer"
+              className="font-medium hover:text-foreground"
+            >
+              Spacing Philosophy Documentation
+            </a>
+          </p>
+        </div>
+      </footer>
+    </div>
+  );
+}