style(views): 统一多个视图的导航栏和标签页样式

调整多个视图的导航栏背景为透明，统一标签页的边距和样式
优化禁用状态的箭头样式，增加指针事件控制

Web/src/views/BalanceView.vue

@@ -1,5 +1,6 @@
 <template>
   <div class="page-container-flex">
+  
     <!-- 顶部导航栏 -->
     <van-nav-bar title="账单" placeholder>
       <template #right>
@@ -20,7 +21,7 @@
         />
       </template>
     </van-nav-bar>
-    <van-tabs v-model:active="tabActive" animated>
+    <van-tabs v-model:active="tabActive" type="card" animated style="margin: 12px 0 2px 0;">
       <van-tab title="账单" name="balance" />
       <van-tab title="邮件" name="email" />
       <van-tab title="消息" name="message" />

Web/src/views/BudgetView.vue

@@ -38,7 +38,7 @@
       </template>
     </van-nav-bar>
 
-    <van-tabs v-model:active="activeTab" type="card" class="budget-tabs">
+    <van-tabs v-model:active="activeTab" type="card" class="budget-tabs" animated style="margin: 12px 4px;">
       <van-tab title="支出" :name="BudgetCategory.Expense">
         <BudgetSummary 
           v-if="activeTab !== BudgetCategory.Savings"

Web/src/views/ScheduledTasksView.vue

@@ -179,4 +179,9 @@ const handleResume = async (task) => {
 .scroll-content {
   padding-bottom: 20px;
 }
+
+/* 设置页面容器背景色 */
+:deep(.van-nav-bar) {
+  background: transparent !important;
+}
 </style>

Web/src/views/StatisticsView.vue

@@ -49,6 +49,7 @@
               <div 
                 class="nav-arrow right" 
                 :class="{ disabled: isCurrentMonth }"
+                :aria-disabled="isCurrentMonth"
                 @click.stop="!isCurrentMonth && changeMonth(1)"
               >
                 <van-icon name="arrow" />
@@ -1040,9 +1041,14 @@ onBeforeUnmount(() => {
 }
 
 .nav-arrow.disabled {
-  color: #f2f3f5;
+  color: #c8c9cc;
   cursor: not-allowed;
-  opacity: 0.3;
+  opacity: 0.35;
+  pointer-events: none;
+}
+
+.nav-arrow.disabled:active {
+  background-color: transparent;
 }
 
 .date-tag {

Web/src/views/TransactionsRecord.vue

@@ -230,7 +230,8 @@ onBeforeUnmount(() => {
   background: var(--van-background-2);
   padding: 4px 12px;
   z-index: 100;
-  border-bottom: 1px solid var(--van-border-color);
+  margin-top: 10px;
+
 }
 
 .top-search-bar :deep(.van-search) {

Web/src/views/UnconfirmedClassification.vue

@@ -159,4 +159,9 @@ onMounted(() => {
   align-items: center;
   height: 200px;
 }
+
+/* 设置页面容器背景色 */
+:deep(.van-nav-bar) {
+  background: transparent !important;
+}
 </style>