epic-ui-guidelines

Epic Stack: UI Guidelines

When to use this skill

Use this skill when you need to:

• Create accessible UI components
• Follow Epic Stack design patterns
• Use Tailwind CSS effectively
• Implement semantic HTML
• Add ARIA attributes correctly
• Create responsive layouts
• Ensure proper form accessibility
• Follow Epic Stack's UI component conventions

Patterns and conventions

UI Philosophy

Following Epic Web principles:

Software is built for people, by people - Accessibility isn't about checking boxes or meeting standards. It's about creating software that works for real people with diverse needs, abilities, and contexts. Every UI decision should prioritize the human experience over technical convenience.

Accessibility is not optional - it's how we ensure our software serves all users, not just some. When you make UI accessible, you're making it better for everyone: clearer labels help all users, keyboard navigation helps power users, and semantic HTML helps search engines.

Example - Human-centered approach:

// ✅ Good - Built for people
function NoteForm() {
	return (
		<Form method="POST">
			<Field
				labelProps={{
					htmlFor: fields.title.id,
					children: 'Note Title', // Clear, human-readable label
				}}
				inputProps={{
					...getInputProps(fields.title),
					placeholder: 'Enter a descriptive title', // Helpful guidance
					autoFocus: true, // Saves time for users
				}}
				errors={fields.title.errors} // Clear error messages
			/>
		</Form>
	)
}

// ❌ Avoid - Technical convenience over user experience
function NoteForm() {
	return (
		<Form method="POST">
			<input name="title" /> {/* No label, no guidance, no accessibility */}
		</Form>
	)
}

Semantic HTML

✅ Good - Use semantic elements:

function UserCard({ user }: { user: User }) {
	return (
		<article>
			<header>
				<h2>{user.name}</h2>
			</header>
			<p>{user.bio}</p>
			<footer>
				<time dateTime={user.createdAt}>{formatDate(user.createdAt)}</time>
			</footer>
		</article>
	)
}

❌ Avoid - Generic divs:

// ❌ Don't use divs for everything
<div>
	<div>{user.name}</div>
	<div>{user.bio}</div>
	<div>{formatDate(user.createdAt)}</div>
</div>

Form Accessibility

✅ Good - Always use labels:

import { Field } from '#app/components/forms.tsx'

<Field
	labelProps={{
		htmlFor: fields.email.id,
		children: 'Email',
	}}
	inputProps={{
		...getInputProps(fields.email, { type: 'email' }),
		autoFocus: true,
		autoComplete: 'email',
	}}
	errors={fields.email.errors}
/>

The Field component automatically:

• Associates labels with inputs using htmlFor and id
• Adds aria-invalid when there are errors
• Adds aria-describedby pointing to error messages
• Ensures proper error announcement

❌ Avoid - Unlabeled inputs:

// ❌ Don't forget labels
<input type="email" name="email" />

ARIA Attributes

✅ Good - Use ARIA appropriately:

// Epic Stack's Field component handles this automatically
<Field
	inputProps={{
		...getInputProps(fields.email, { type: 'email' }),
		// aria-invalid and aria-describedby are added automatically
	}}
	errors={fields.email.errors} // Error messages are linked via aria-describedby
/>

✅ Good - ARIA for custom components:

function LoadingButton({ isLoading, children }: { isLoading: boolean; children: React.ReactNode }) {
	return (
		<button aria-busy={isLoading} disabled={isLoading}>
			{isLoading ? 'Loading...' : children}
		</button>
	)
}

Using Radix UI Components

Epic Stack uses Radix UI for accessible, unstyled components.

✅ Good - Use Radix primitives:

import * as Dialog from '@radix-ui/react-dialog'
import { Button } from '#app/components/ui/button.tsx'

function MyDialog() {
	return (
		<Dialog.Root>
			<Dialog.Trigger asChild>
				<Button>Open Dialog</Button>
			</Dialog.Trigger>
			<Dialog.Portal>
				<Dialog.Overlay className="fixed inset-0 bg-black/50" />
				<Dialog.Content className="fixed top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 bg-white p-6">
					<Dialog.Title>Dialog Title</Dialog.Title>
					<Dialog.Description>Dialog description</Dialog.Description>
					<Dialog.Close asChild>
						<Button>Close</Button>
					</Dialog.Close>
				</Dialog.Content>
			</Dialog.Portal>
		</Dialog.Root>
	)
}

Radix components automatically handle:

• Keyboard navigation
• Focus management
• ARIA attributes
• Screen reader announcements

Tailwind CSS Patterns

✅ Good - Use Tailwind utility classes:

function Card({ children }: { children: React.ReactNode }) {
	return (
		<div className="rounded-lg border border-gray-200 bg-white p-6 shadow-sm">
			{children}
		</div>
	)
}

✅ Good - Use Tailwind responsive utilities:

<div className="grid grid-cols-1 gap-4 md:grid-cols-2 lg:grid-cols-3">
	{items.map(item => (
		<Card key={item.id}>{item.name}</Card>
	))}
</div>

✅ Good - Use Tailwind dark mode:

<div className="bg-white text-gray-900 dark:bg-gray-800 dark:text-gray-100">
	{content}
</div>

Error Handling in Forms

✅ Good - Display errors accessibly:

import { Field, ErrorList } from '#app/components/forms.tsx'

<Field
	labelProps={{ htmlFor: fields.email.id, children: 'Email' }}
	inputProps={getInputProps(fields.email, { type: 'email' })}
	errors={fields.email.errors} // Errors are displayed below input
/>

<ErrorList errors={form.errors} id={form.errorId} /> // Form-level errors

Errors are automatically:

• Associated with inputs via aria-describedby
• Announced to screen readers
• Visually distinct with error styling

Focus Management

✅ Good - Visible focus indicators:

// Tailwind's default focus:ring handles this
<button className="focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2">
	Click me
</button>

✅ Good - Focus on form errors:

import { useEffect, useRef } from 'react'

function FormWithErrorFocus() {
	const firstErrorRef = useRef<HTMLInputElement>(null)

	useEffect(() => {
		if (actionData?.errors && firstErrorRef.current) {
			firstErrorRef.current.focus()
		}
	}, [actionData?.errors])

	return <Field inputProps={{ ref: firstErrorRef, ... }} />
}

Keyboard Navigation

✅ Good - Keyboard accessible components:

// Radix components handle keyboard navigation automatically
<Dialog.Trigger asChild>
	<Button>Open</Button>
</Dialog.Trigger>

// Custom components should support keyboard
<button
	onKeyDown={(e) => {
		if (e.key === 'Enter' || e.key === ' ') {
			handleClick()
		}
	}}
>
	Custom Button
</button>

Color Contrast

✅ Good - Use accessible color combinations:

// Use Tailwind's semantic colors that meet WCAG AA
<div className="bg-white text-gray-900"> // High contrast
<div className="text-blue-600 hover:text-blue-700"> // Accessible links

❌ Avoid - Low contrast text:

// ❌ Don't use low contrast
<div className="bg-gray-100 text-gray-200"> // Very low contrast

Responsive Design

✅ Good - Mobile-first approach:

<div className="
	flex flex-col gap-4
	md:flex-row md:gap-8
	lg:gap-12
">
	{/* Content */}
</div>

✅ Good - Responsive typography:

<h1 className="text-2xl md:text-3xl lg:text-4xl">
	Responsive Heading
</h1>

Loading States

✅ Good - Accessible loading indicators:

import { useNavigation } from 'react-router'

function SubmitButton() {
	const navigation = useNavigation()
	const isSubmitting = navigation.state === 'submitting'

	return (
		<button
			type="submit"
			disabled={isSubmitting}
			aria-busy={isSubmitting}
		>
			{isSubmitting ? 'Saving...' : 'Save'}
		</button>
	)
}

Icon Usage

✅ Good - Decorative icons:

import { Icon } from '#app/components/ui/icon.tsx'

<button aria-label="Delete note">
	<Icon name="trash" />
	<span className="sr-only">Delete note</span>
</button>

✅ Good - Semantic icons:

<button>
	<Icon name="check" aria-hidden="true" />
	Save
</button>

Skip Links

✅ Good - Add skip to main content:

// In your root layout
<a href="#main-content" className="sr-only focus:not-sr-only focus:absolute focus:top-0 focus:left-0 focus:z-50 focus:p-4 focus:bg-blue-600 focus:text-white">
	Skip to main content
</a>

<main id="main-content">
	{/* Main content */}
</main>

Progressive Enhancement

✅ Good - Forms work without JavaScript:

// Conform forms work without JavaScript
<Form method="POST" {...getFormProps(form)}>
	<Field {...props} />
	<StatusButton type="submit">Submit</StatusButton>
</Form>

Forms automatically:

• Submit via native HTML forms if JavaScript is disabled
• Validate server-side
• Show errors appropriately

Screen Reader Best Practices

✅ Good - Use semantic HTML first:

// ✅ Semantic HTML provides context automatically
<nav aria-label="Main navigation">
	<ul>
		<li><a href="/">Home</a></li>
		<li><a href="/about">About</a></li>
	</ul>
</nav>

✅ Good - Announce dynamic content:

import { useNavigation } from 'react-router'

function SearchResults({ results }: { results: Result[] }) {
	const navigation = useNavigation()
	const isSearching = navigation.state === 'loading'

	return (
		<div
			role="status"
			aria-live="polite"
			aria-atomic="true"
			className="sr-only"
		>
			{isSearching ? 'Searching...' : `${results.length} results found`}
		</div>
	)
}

✅ Good - Live regions for important updates:

function ToastContainer({ toasts }: { toasts: Toast[] }) {
	return (
		<div aria-live="assertive" aria-atomic="true" className="sr-only">
			{toasts.map(toast => (
				<div key={toast.id} role="alert">
					{toast.message}
				</div>
			))}
		</div>
	)
}

**ARIA li

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