Update min-height.md

docs/uni-app-x/css/min-height.md

@@ -2,11 +2,12 @@
 
 
 <!-- CSSJSON.min-height.description -->
-
+### App平台差异  
+App平台默认值为0px
 <!-- CSSJSON.min-height.syntax -->
 
 <!-- CSSJSON.min-height.values -->
 
 <!-- CSSJSON.min-height.compatibility -->
 
-<!-- CSSJSON.min-height.reference -->
\ No newline at end of file
+<!-- CSSJSON.min-height.reference -->