```python
def case_count(text: str) -> list:
    if not text.isalpha():  # If the text contains no letters, return two zeros
        return [0, 0]
    
    capital_count = sum(1 for char in text if char.isupper())
    lowercase_count = len(text) - capital_count
    
    return [capital_count, lowercase_count]
```