You're developing a slide-in sidebar menu. What CSS property would be most efficient to animate for smooth performance?

When developing a slide-in sidebar menu or any animation, using the transform property is the most efficient choice for smooth performance. This is because the transform property can be hardware-accelerated by the browser, leading to faster and smoother animations. Using properties like margin, padding, or width for animations can cause reflows and repaints, which can be less performant.