1.修改cardview背景阴影。

app/src/main/res/drawable/shape_shadow_bg.xml

 <?xml version="1.0" encoding="utf-8"?>
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
-    <item
-        android:left="2dp"
-        android:top="2dp">
+    <item>
         <shape android:shape="rectangle">
             <!--这里可以是梯度的值，也可以是solid，看实际的效果自己调测-->
             <gradient
                 android:centerY="50"
                 android:endColor="#E9F4FD"
                 android:startColor="#DCF1FF" />
-            <corners
-                android:radius="13dp" />
+            <corners android:radius="13dp" />
         </shape>
     </item>
 
-    <item
-        android:bottom="2dp"
-        android:right="2dp">
+    <item>
         <shape android:shape="rectangle">
             <solid android:color="#99FFFFFF" />
-            <stroke android:width="2dp" android:color="@color/white"/>
+            <stroke
+                android:width="2dp"
+                android:color="@color/white" />
             <corners android:radius="13dp" />
         </shape>
     </item>