539 层叠上下文的创建（层叠上下⽂形成条件）

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>层叠上下文的创建-案例解析</title>
</head>

<body>
  <!-- 【z-index:auto，所以没有产生层叠上下文】 -->
  <!-- 案例解析一  -->
  <div style="position:relative; z-index:auto;">
    <img src="images/mm1.jpg" style="position:absolute; z-index:2; margin-left: 50px;">
  </div>
  <div style="position:relative; z-index:auto;">
    <img src="images/mm2.jpg" style="position:relative; z-index:1;">
  </div>

  <hr>

  <!-- 案例解析一  -->
  <div style="position:relative; z-index:0;">
    <img src="images/mm1.jpg" style="position:absolute; z-index:2;">
  </div>
  <div style="position:relative; z-index:0;">
    <img src="images/mm2.jpg" style="position:relative; z-index:1; margin-left: 50px;">
  </div>
</body>

</html>