fix: demo double scrollbar on Firefox

Author: Guillaume Chau

docs-src/src/App.vue

@@ -37,9 +37,14 @@ body {
   align-items: stretch;
 }
 
+.menu {
+  flex: auto 0 0;
+}
+
 .menu,
 .page {
   padding: 12px;
+  box-sizing: border-box;
 }
 
 .package {
@@ -70,7 +75,6 @@ body {
   background: #42b983;
 }
 
-
 .vue-recycle-scroller__item-container,
 .vue-recycle-scroller__item-wrapper {
   box-sizing: border-box;

docs-src/src/components/DynamicScrollerDemo.vue

@@ -72,6 +72,10 @@ export default {
   height: 100%;
 }
 
+.dynamic-scroller-demo {
+  overflow: hidden;
+}
+
 .notice {
   padding: 24px;
   font-size: 20px;

docs-src/src/components/RecycleScrollerDemo.vue

@@ -95,15 +95,6 @@ export default {
     pageModeFullPage: true,
   }),
 
-  watch: {
-    count () {
-      this.generateItems()
-    },
-    enableLetters () {
-      this.generateItems()
-    },
-  },
-
   computed: {
     countInput: {
       get () {
@@ -132,6 +123,15 @@ export default {
     },
   },
 
+  watch: {
+    count () {
+      this.generateItems()
+    },
+    enableLetters () {
+      this.generateItems()
+    },
+  },
+
   mounted () {
     this.$nextTick(this.generateItems)
     window.scroller = this.$refs.scroller