问题1：The safe area layout guide is the space available to our view, excluding rounded corners and notches.
答案：All important content should lie inside the safe area, or you risk it being obscured.
问题2：layoutMarginsGuide and safeAreaLayoutGuide are the same thing.
答案：Not quite: layoutMarginsGuide is inside the safeAreaLayoutGuide, so it will be slightly smaller.
问题3: Activating multiple constraints at once is faster than modifying isActive for each one.
答案：Apple explicitly recommends using activate() for this purpose.
问题4: Content hugging priority controls how likely Auto Layout is to make a view smaller than its intrinsic content size.
答案：Content hugging priority controls how likely Auto Layout is to make a view larger than its intrinsic content size.