input: from typing import List
  
  def analyze_sentiment(text: str) -> str:
      """ Analyze the sentiment of a given text and categorize it into positive, negative, or neutral.
      >>> analyze_sentiment("I love this product! It's amazing.")
      'positive'
      >>> analyze_sentiment("I hate this product! It's terrible.")
      'negative'
      >>> analyze_sentiment("This product is just okay.")
      'neutral'
      """
output:     positive_words = ["love", "amazing", "great", "excellent"]
      negative_words = ["hate", "terrible", "awful", "bad"]
      
      text_lower = text.lower()
      words = text_lower.split()
      
      positive_count = sum(word in positive_words for word in words)
      negative_count = sum(word in negative_words for word in words)
      
      if positive_count > negative_count:
          return 'positive'
      elif negative_count > positive_count:
          return 'negative'
      else:
          return 'neutral'