Improve.

- make the refresh interval setting makes effect immediately.
- auto stop/restart status update when app goto background/resume

lib/view/page/server/detail.dart

@@ -210,8 +210,8 @@ class _ServerDetailPageState extends State<ServerDetailPage>
               _buildMemExplain(convertMB(ss.memory.used), pColor),
               _buildMemExplain(
                   convertMB(ss.memory.cache), pColor.withAlpha(77)),
-              _buildMemExplain(
-                  convertMB(ss.memory.total - ss.memory.avail), progressColor.resolve(context))
+              _buildMemExplain(convertMB(ss.memory.total - ss.memory.used),
+                  progressColor.resolve(context))
             ],
           ),
           const SizedBox(
@@ -243,7 +243,7 @@ class _ServerDetailPageState extends State<ServerDetailPage>
     ));
   }
 
-  Widget _buildMemExplain(String type, Color color) {
+  Widget _buildMemExplain(String value, Color color) {
     return Row(
       children: [
         Container(
@@ -252,7 +252,12 @@ class _ServerDetailPageState extends State<ServerDetailPage>
           width: 11,
         ),
         const SizedBox(width: 4),
-        Text(type, style: style11, textScaleFactor: 1.0)
+        Text(
+          value,
+          style: style11,
+          textScaleFactor: 1.0,
+          textAlign: TextAlign.center,
+        )
       ],
     );
   }

lib/view/page/server/tab.dart

@@ -67,7 +67,7 @@ class _ServerPageState extends State<ServerPage>
         child: AnimationLimiter(
             child: Column(
                 children: AnimationConfiguration.toStaggeredList(
-          duration: const Duration(milliseconds: 777),
+          duration: const Duration(milliseconds: 477),
           childAnimationBuilder: (widget) => SlideAnimation(
             verticalOffset: 77.0,
             child: FadeInAnimation(
@@ -155,7 +155,9 @@ class _ServerPageState extends State<ServerPage>
                         accelerationCurve: Curves.linear,
                         decelerationDuration: const Duration(seconds: 3),
                         decelerationCurve: Curves.linear,
-                        text: topRightStr, textScaleFactor: 1.0, style: style),
+                        text: topRightStr,
+                        textScaleFactor: 1.0,
+                        style: style),
                   )
                 : Text(topRightStr, style: style, textScaleFactor: 1.0),
           ],