title: How to add different constraints depend on iPhone screen size?
body: <p>This is my xib file viewed as iPhone6/iPhone7,it looks good.</p>
  
  <p><a href="https://i.stack.imgur.com/euvN4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/euvN4.png" alt="enter image description here"></a></p>
  
  <p>but if i turn it into iPhoneSE,it becomes abnormal.</p>
  
  <p><a href="https://i.stack.imgur.com/dNvyB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/dNvyB.png" alt="enter image description here"></a></p>
  
  <p>Becasue the space blank doesn't change when the device changes,and i can not change the space constraint adapting to device without code.</p>