style: 优化设置 tabBar 弹框样式

pages/tabBar/API.uvue

@@ -125,16 +125,11 @@
   }
 
   .popup {
-    width: 100%;
-    /* #ifdef APP */
-    position: absolute;
-    height: 100%;
-    /* #endif */
-    /* #ifndef APP */
     position: fixed;
-    top: var(--window-top);
-    bottom: var(--window-bottom);
-    /* #endif */
+    top: 0;
+    bottom: 0;
+    left: 0;
+    right: 0;
     align-items: center;
     justify-content: center;
     display: none;