fast-next-template/frontend/docs/design-system/00-quick-start.md

Quick Start Guide

Get up and running with the FastNext design system immediately. This guide covers the essential patterns you need to build 80% of interfaces.

---

TL;DR

// 1. Import from @/components/ui/*
import { Button } from '@/components/ui/button';
import { Card, CardHeader, CardTitle, CardContent } from '@/components/ui/card';

// 2. Use semantic color tokens
className="bg-primary text-primary-foreground"
className="text-destructive"

// 3. Use spacing scale (4, 8, 12, 16, 24, 32...)
className="p-4 space-y-6"

// 4. Build layouts with these patterns
<div className="container mx-auto px-4 py-8">
  <div className="max-w-4xl mx-auto space-y-6">
    {/* Your content */}
  </div>
</div>

---

1. Essential Components

Buttons

import { Button } from '@/components/ui/button';

// Primary action
<Button>Save Changes</Button>

// Danger action
<Button variant="destructive">Delete</Button>

// Secondary action
<Button variant="outline">Cancel</Button>

// Subtle action
<Button variant="ghost">Skip</Button>

// Sizes
<Button size="sm">Small</Button>
<Button size="default">Default</Button>
<Button size="lg">Large</Button>

See all button variants

---

Cards

import {
  Card,
  CardHeader,
  CardTitle,
  CardDescription,
  CardContent,
  CardFooter
} from '@/components/ui/card';

<Card>
  <CardHeader>
    <CardTitle>User Profile</CardTitle>
    <CardDescription>Manage your account settings</CardDescription>
  </CardHeader>
  <CardContent>
    <p>Card content goes here</p>
  </CardContent>
  <CardFooter>
    <Button>Save</Button>
  </CardFooter>
</Card>

See card examples

---

Forms

import { Label } from '@/components/ui/label';
import { Input } from '@/components/ui/input';

<div className="space-y-2">
  <Label htmlFor="email">Email</Label>
  <Input
    id="email"
    type="email"
    placeholder="you@example.com"
    {...register('email')}
  />
  {errors.email && (
    <p className="text-sm text-destructive">
      {errors.email.message}
    </p>
  )}
</div>

See form patterns | Form examples

---

Dialogs/Modals

import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
  DialogDescription,
  DialogFooter,
  DialogTrigger
} from '@/components/ui/dialog';

<Dialog>
  <DialogTrigger asChild>
    <Button>Open Dialog</Button>
  </DialogTrigger>
  <DialogContent>
    <DialogHeader>
      <DialogTitle>Confirm Action</DialogTitle>
      <DialogDescription>
        Are you sure you want to proceed?
      </DialogDescription>
    </DialogHeader>
    <DialogFooter>
      <Button variant="outline">Cancel</Button>
      <Button>Confirm</Button>
    </DialogFooter>
  </DialogContent>
</Dialog>

See dialog examples

---

Alerts

import { Alert, AlertDescription, AlertTitle } from '@/components/ui/alert';
import { AlertCircle } from 'lucide-react';

// Default alert
<Alert>
  <AlertCircle className="h-4 w-4" />
  <AlertTitle>Heads up!</AlertTitle>
  <AlertDescription>
    This is an informational message.
  </AlertDescription>
</Alert>

// Error alert
<Alert variant="destructive">
  <AlertCircle className="h-4 w-4" />
  <AlertTitle>Error</AlertTitle>
  <AlertDescription>
    Something went wrong. Please try again.
  </AlertDescription>
</Alert>

See all component variants

---

2. Essential Layouts (1 minute)

Page Container

// Standard page layout
<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>{/* Content */}</Card>
  </div>
</div>

Dashboard Grid

// Responsive card grid
<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>

Form Layout

// Centered form with max width
<div className="container mx-auto px-4 py-8">
  <Card className="max-w-md mx-auto">
    <CardHeader>
      <CardTitle>Login</CardTitle>
    </CardHeader>
    <CardContent>
      <form className="space-y-4">
        {/* Form fields */}
      </form>
    </CardContent>
  </Card>
</div>

See all layout patterns | Layout examples

---

3. Color System

Always use semantic tokens, never arbitrary colors:

// ✅ GOOD - Semantic tokens
<div className="bg-primary text-primary-foreground">Primary</div>
<div className="bg-destructive text-destructive-foreground">Error</div>
<div className="bg-muted text-muted-foreground">Disabled</div>
<p className="text-foreground">Body text</p>
<p className="text-muted-foreground">Secondary text</p>

// ❌ BAD - Arbitrary colors
<div className="bg-blue-500 text-white">Don't do this</div>

Available tokens:

• primary - Main brand color, CTAs
• destructive - Errors, delete actions
• muted - Disabled states, subtle backgrounds
• accent - Hover states, highlights
• foreground - Body text
• muted-foreground - Secondary text
• border - Borders, dividers

See complete color system

---

4. Spacing System

Use multiples of 4 (Tailwind's base unit is 0.25rem = 4px):

// ✅ GOOD - Consistent spacing
<div className="p-4 space-y-6">
  <div className="mb-8">Content</div>
</div>

// ❌ BAD - Arbitrary spacing
<div className="p-[13px] space-y-[17px]">
  <div className="mb-[23px]">Content</div>
</div>

Common spacing values:

• 2 (8px) - Tight spacing
• 4 (16px) - Standard spacing
• 6 (24px) - Section spacing
• 8 (32px) - Large gaps
• 12 (48px) - Section dividers

Pro tip: Use gap- for grids/flex, space-y- for vertical stacks:

// Grid spacing
<div className="grid grid-cols-3 gap-6">

// Stack spacing
<div className="space-y-4">

Read spacing philosophy

---

5. Responsive Design

Mobile-first approach with Tailwind breakpoints:

<div className="
  p-4           // Mobile: 16px padding
  sm:p-6        // Tablet: 24px padding
  lg:p-8        // Desktop: 32px padding
">
  <h1 className="
    text-2xl     // Mobile: 24px
    sm:text-3xl  // Tablet: 30px
    lg:text-4xl  // Desktop: 36px
    font-bold
  ">
    Responsive Title
  </h1>
</div>

// Grid columns
<div className="grid
  grid-cols-1        // Mobile: 1 column
  md:grid-cols-2     // Tablet: 2 columns
  lg:grid-cols-3     // Desktop: 3 columns
  gap-6
">

Breakpoints:

• sm: 640px+
• md: 768px+
• lg: 1024px+
• xl: 1280px+

---

6. Accessibility

Always include:

// Labels for inputs
<Label htmlFor="email">Email</Label>
<Input id="email" type="email" />

// ARIA for errors
<Input
  aria-invalid={!!errors.email}
  aria-describedby={errors.email ? 'email-error' : undefined}
/>
{errors.email && (
  <p id="email-error" className="text-sm text-destructive">
    {errors.email.message}
  </p>
)}

// ARIA labels for icon-only buttons
<Button size="icon" aria-label="Close dialog">
  <X className="h-4 w-4" />
</Button>

Complete accessibility guide

---

7. Common Patterns Cheat Sheet

Loading State

import { Skeleton } from '@/components/ui/skeleton';

{isLoading ? (
  <Skeleton className="h-12 w-full" />
) : (
  <div>{content}</div>
)}

Dropdown Menu

import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger
} from '@/components/ui/dropdown-menu';

<DropdownMenu>
  <DropdownMenuTrigger asChild>
    <Button variant="outline">Options</Button>
  </DropdownMenuTrigger>
  <DropdownMenuContent>
    <DropdownMenuItem>Edit</DropdownMenuItem>
    <DropdownMenuItem>Delete</DropdownMenuItem>
  </DropdownMenuContent>
</DropdownMenu>

Badge/Tag

import { Badge } from '@/components/ui/badge';

<Badge>New</Badge>
<Badge variant="destructive">Urgent</Badge>
<Badge variant="outline">Draft</Badge>

---

8. Next Steps

You now know enough to build most interfaces! For deeper knowledge:

Learn More

• Components: Complete component guide
• Layouts: Layout patterns
• Forms: Form patterns & validation
• Custom Components: Component creation guide

Interactive Examples

• Component Showcase - All components with code
• Layout Examples - Before/after comparisons
• Form Examples - Complete form implementations

Reference

• Quick Reference Tables - Bookmark this for lookups
• Foundations - Complete color/spacing/typography guide

---

🎯 Golden Rules

Remember these and you'll be 95% compliant:

1. ✅ Import from @/components/ui/*
2. ✅ Use semantic colors: bg-primary, not bg-blue-500
3. ✅ Use spacing scale: 4, 8, 12, 16, 24, 32 (multiples of 4)
4. ✅ Use cn() for className merging: cn("base", conditional && "extra", className)
5. ✅ Add accessibility: Labels, ARIA, keyboard support
6. ✅ Test in dark mode: Toggle with theme switcher

---

🚀 Start Building!

You're ready to build. When you hit edge cases or need advanced patterns, refer back to the full documentation.

Bookmark these:

• Quick Reference - For quick lookups
• AI Guidelines - If using AI assistants
• Component Showcase - For copy-paste examples

Happy coding! 🎨