方法区域上的JVM类型表示(JVM type representation on method area)

 当前1.0.0版本的<spinner-backdrop>没有CSS属性/ mixin来设置z-index ，但最近添加了--spinner-backdrop-overlay mixin，但尚未发布。 您可以使用mixin来设置z-index如下所示： 
 
<style is="custom-style">
  spinner-backdrop {
    --spinner-backdrop-overlay: {
      z-index: 0;
    };
  }
</style>
 
 如果<spinner-backdrop>位于Polymer元素（ <dom-module> ）内，则<style>不需要is="custom-style" 。 否则，需要正确应用mixin。 
 
 演示（在<dom-module> ） 
 
 演示（在index.html ） 

The current 1.0.0 release of <spinner-backdrop> has no CSS property/mixin to set the z-index, but the --spinner-backdrop-overlay mixin was recently added and not yet released. You'd be able to use the mixin to set the z-index like this:
 
<style is="custom-style">
  spinner-backdrop {
    --spinner-backdrop-overlay: {
      z-index: 0;
    };
  }
</style>
 
If <spinner-backdrop> is inside a Polymer element (<dom-module>), your <style> doesn't need is="custom-style". Otherwise, it's needed to apply the mixin properly.
 
demo (in <dom-module>)
 
demo (in index.html)