const emailRegex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/;

function isValidEmail(email) {
  return emailRegex.test(email);
}

// Example usage:
// console.log(isValidEmail('test@example.com')); // true
// console.log(isValidEmail('invalid-email'));    // false