factor:布局颜色重构

lib/pages/stats_page.dart

@@ -76,10 +76,8 @@ class StatsPageState extends State<StatsPage> {
         buildChartDivider(context),
         const SizedBox(height: 3),
         Expanded(
-          child: barChart(
+          child: rankChart(
             context: context,
-            xAxisName: '名称',
-            yAxisName: '访问量',
             unit: '人次',
             data: provider.visitRankStats,
           ),
@@ -114,10 +112,8 @@ class StatsPageState extends State<StatsPage> {
         buildChartDivider(context),
         const SizedBox(height: 3),
         Expanded(
-          child: barChart(
+          child: rankChart(
             context: context,
-            xAxisName: '名称',
-            yAxisName: '时长',
             unit: '分钟',
             data: provider.readRankStats,
           ),