调整整体样式

packages/artplayer/src/style/loading.scss

@@ -2,7 +2,7 @@
     .artplayer-loading {
         display: none;
         position: absolute;
-        z-index: 60;
+        z-index: 70;
         left: 0;
         top: 0;
         right: 0;
@@ -13,4 +13,10 @@
         justify-content: center;
         pointer-events: none;
     }
+
+    &.artplayer-loading-show {
+        .artplayer-loading {
+            display: flex;
+        }
+    }
 }