Frontend UI

Related Generic Skills

• typescript - Const types, flat interfaces
• react-19 - No useMemo/​useCallback, compiler
• tailwind-4 - cn() utility, styling rules
• zod-4 - Schema validation
• zustand-5 - State management
• motion - Animations

CRITICAL: Mobile First

• ALWAYS: Use Mobile First approach for responsive design. then desktop styles.

Tech Stack (Versions)

React 19.2.3 | Tailwind 4.1.18 | shadcn/​ui
Zod 4.3.5 | React Hook Form 7.71.0 | Zustand 5.0.10" | Recharts 3.6.0 | React Router 7.12.0 | Motion 12.26.2 | TanStack Query 5.90.16 | TanStack Table 8.21.3 |

DECISION TREES

Component Placement

New feature UI? → components/​ui + Tailwind

Code Location

Types → types/​{domain}.ts
Utils → lib/
Hooks → {feature}/​hooks.ts
shadcn components  → components/​ui/
pages (React Router) → pages/

Styling Decision

Tailwind class exists? → className
Dynamic value?         → style prop
Conditional styles?    → cn()
Static only?           → className (no cn())
Recharts/​library?      → CHART_COLORS constant + var()

ANIMATIONS

• Use motion for all animations.
• Prefer simple animations (opacity, translate, scale).

PROJECT STRUCTURE

react-app/
├── main.tsx/          # React app entry point
├── components/​ui/   # Shared UI components (shadcn)
├── pages/          # React Router pages
├── types/               # Shared types
├── hooks/               # Shared hooks
├── lib/                 # Utilities
├── store/               # Zustand state
└── styles/              # Global CSS

Form + Validation Pattern

"use client";
import { useForm } from "react-hook-form";
import { zodResolver } from "@hookform/​resolvers/​zod";
import { z } from "zod";

const schema = z.object({
  email: z.email(),  // Zod 4 syntax
  name: z.string().min(1),
});

type FormData = z.infer<typeof schema>;

export function MyForm() {
  const { register, handleSubmit, formState: { errors } } = useForm<FormData>({
    resolver: zodResolver(schema),
  });

  const onSubmit = async (data: FormData) => {
    await serverAction(data);
  };

  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      <input {...register("email")} />
      {errors.email && <span>{errors.email.message}</​span>}
      <button type="submit">Submit</​button>
    </​form>
  );
}