Resources

const [menuOpen, setMenuOpen] = useState(false);

return (
  <nav className="relative">
    <button 
      onClick={() => setMenuOpen(!menuOpen)}
      aria-expanded={menuOpen}
      aria-label="Toggle menu"
    >
      {menuOpen ? <XIcon /> : <MenuIcon />}
    </button>
    
    {menuOpen && (
      <div className="absolute top-full">
        {/* Menu items */}
      </div>
    )}
  </nav>
);

import { useState, useEffect } from 'react';

function LazyImage({ src, alt, ...props }) {
  const [loaded, setLoaded] = useState(false);
  
  return (
    <img
      src={src || "/placeholder.svg"}
      alt={alt}
      className={`transition-opacity duration-500 
        ${loaded ? 'opacity-100' : 'opacity-0'}`}
      onLoad={() => setLoaded(true)}
      loading="lazy"
      {...props}
    />
  );
}

function useFormValidation(initialState, validate) {
  const [values, setValues] = useState(initialState);
  const [errors, setErrors] = useState({});
  const [isSubmitting, setIsSubmitting] = useState(false);
  
  useEffect(() => {
    if (isSubmitting) {
      const noErrors = Object.keys(errors).length === 0;
      if (noErrors) {
        // Submit form
        setIsSubmitting(false);
      } else {
        setIsSubmitting(false);
      }
    }
  }, [errors, isSubmitting]);
  
  // More code...
}