containing-block-change-button-ref.html (346B)
1 <!doctype html> 2 <meta charset="utf-8"> 3 <style> 4 #button { 5 width: 400px; 6 height: 400px; 7 margin: 50px; 8 padding: 0; 9 border: 0; 10 background-color: purple; 11 vertical-align: top; 12 } 13 #button > div { 14 width: 100px; 15 height: 100px; 16 background-color: green; 17 } 18 </style> 19 <button id="button"> 20 <div></div> 21 </button>