Level 3: The Shadowy Slip-Up

In the depths of the CSS Ninja Training Academy, a young ninja named Bob is struggling to master the art of subtle shadows. His sensei, a wise old ninja named Steve, has set him up with the following exercises:

• Exercise 1: Add a box shadow to a previous lesson's example.
• Exercise 2: Create a subtle gradient effect on a earlier lesson's background.
• Exercise 3: Use CSS transforms to create a ninja mask that defies the laws of physics!

Remember: Shadows are like secrets, but not too secret. A good ninja must balance subtlety with showmanship.

Practice, young ninja. The art of CSS ninja warfare is not for the faint of heart... or of code.