feat: 会员中心全局暗色主题重构

阶段一：全局覆盖
- 新增 dark-override.css (450+ 行)，覆盖所有 Element UI 组件暗色样式
  - 输入框、表格、Tabs、弹窗、按钮、分页、复选框、下拉框等
  - 侧边栏、顶栏、主内容区暗色背景
  - 滚动条、日期选择器、消息面板等
- header.php 引入 dark-override.css

阶段二：页面独立 CSS 暗色化（22 个文件）
- 白色背景 #fff → #161b22
- 浅灰背景 #F3F5F9 → #0d1117
- 深色文字 #171725/#1E2736 → #E6E8EB
- 灰色文字 #8692B0 → #8B949E
- 浅色边框 #E6E7EB → rgba(255,255,255,0.06)
- 悬停背景 #F5F7FA → #21262d

clientarea/hgcloud/css/orderDetail.css

@@ -5,7 +5,7 @@
   padding-bottom: 0.2rem;
   display: flex;
   align-items: center;
-  border-bottom: 1px solid #E6E7EB;
+  border-bottom: 1px solid rgba(255,255,255,0.06);
   margin-bottom: 0.4rem;
 }
 .page-top .back-btn {
@@ -20,7 +20,7 @@
 .page-top .top-title {
   margin-left: 0.25rem;
   font-size: 0.28rem;
-  color: #1E2736;
+  color: #E6E8EB;
 }
 .order-info {
   display: flex;
@@ -30,7 +30,7 @@
 }
 .order-info .info-left .order-user {
   font-size: 0.18rem;
-  color: #1E2736;
+  color: #E6E8EB;
 }
 .order-info .info-right {
   display: flex;
@@ -58,7 +58,7 @@
   margin-top: 0.1rem;
   font-weight: bold;
   font-size: 0.14rem;
-  color: #1E2736;
+  color: #E6E8EB;
 }
 .order-info .pay-status {
   border-radius: 0.03rem;
@@ -83,7 +83,7 @@
 }
 .order-info .order-num {
   margin-top: 0.13rem;
-  color: #1E2736;
+  color: #E6E8EB;
   font-size: 0.14rem;
 }
 .order-info .order-num .num-text {
@@ -99,7 +99,7 @@
 }
 .self-field .self-num {
   display: flex;
-  color: #1E2736;
+  color: #E6E8EB;
   font-size: 0.14rem;
 }
 .self-field .self-num .field-name {
@@ -132,7 +132,7 @@
 }
 .order-table .table-item .des,
 .order-table .table-item .money {
-  color: #1E2736;
+  color: #E6E8EB;
 }
 .order-table .table-item .des-text {
   margin-right: 0.5rem;
@@ -148,7 +148,7 @@
   border-bottom: 0.01rem solid #E6E7EB;
 }
 .order-table .total-money {
-  color: #1E2736;
+  color: #E6E8EB;
   margin-right: 0.3rem;
 }
 .order-transaction {
@@ -163,7 +163,7 @@
   border-bottom: 0.01rem solid #E6E7EB;
 }
 .order-transaction .table-top {
-  color: #1E2736;
+  color: #E6E8EB;
   padding: 0.13rem 0.2rem 0.14rem;
 }
 .order-transaction .table-bottom {