CSS Specificity: If there's a more specific CSS rule targeting the same element, it will take precedence. This could be a rule with a higher specificity (e.g., an ID selector) or a rule that comes later in the stylesheet.
Inheritance Issues: Some CSS properties are inherited by child elements, while others are not. If the style you're trying to apply is not inherited, you'll need to explicitly target the nested paragraph element.
Browser Compatibility: While rare, there might be a minor browser compatibility issue where certain styles are not applied correctly in specific browsers.
Typos or Syntax Errors: Double-check your CSS for any typos or syntax errors in the selector or property names.