Revert "codex 试用，美化"

This reverts commit f2af83a72f.

admin/dashboard/templates/base.html

@@ -16,10 +16,10 @@
         body {
             margin: 0;
             padding: 0;
-            background: #f2f6fb;
+            background: #f7f7f8;
             font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
                          "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei";
-            color: #22324a;
+            color: #333;
             overflow: hidden; /* 禁止 body 出滚动条 */
         }
 
@@ -172,15 +172,13 @@
             flex: 1;
             padding: 16px;
             overflow-y: auto;
-            background: #f2f6fb;
         }
 
         /* 全局卡片样式统一 */
         .el-card {
             border-radius: 0 !important;
-            box-shadow: 0 6px 18px rgba(11, 29, 51, 0.06) !important;
-            border: 1px solid #d6e6ff !important;
-            background: #ffffff !important;
+            box-shadow: 0 4px 12px rgba(0,0,0,0.04) !important;
+            border: 1px solid #e5e6eb !important;
         }
         .el-card__body {
             padding: 12px !important;