终端与时区分组逻辑微调

frontend/components/dashboard/ScanTerminalDashboard.tsx

@@ -31,6 +31,7 @@ import {
   getSignalState,
   resolveTradingRegionKey,
   TRADING_REGIONS,
+  detectLocalRegion,
 } from "@/components/dashboard/scan-terminal/continent-grouping";
 import { MobileCityCard } from "@/components/dashboard/scan-terminal/MobileCityCard";
 import { MobileRegionTabs } from "@/components/dashboard/scan-terminal/MobileRegionTabs";
@@ -470,6 +471,10 @@ function PolyWeatherTerminal({
   const [activeNavKey, setActiveNavKey] = useState<string>("contracts");
   const [selectedRegionKey, setSelectedRegionKey] = useState<string>("east_asia");
 
+  useEffect(() => {
+    setSelectedRegionKey(detectLocalRegion());
+  }, []);
+
   const NAV_ITEMS = [
     { key: "contracts", Icon: Table2, labelEn: "Contracts", labelZh: "天气合约" },
     { key: "markets", Icon: Activity, labelEn: "Markets", labelZh: "市场概览" },

frontend/components/dashboard/scan-terminal/continent-grouping.ts

@@ -12,6 +12,18 @@ export const TRADING_REGIONS = [
 
 export type TradingRegionKey = (typeof TRADING_REGIONS)[number]["key"];
 
+/** Map browser timezone offset (hours) to the closest trading region. */
+export function detectLocalRegion(): TradingRegionKey {
+  const offset = -new Date().getTimezoneOffset() / 60; // UTC offset in hours
+  if (offset >= 8) return "east_asia";
+  if (offset >= 7) return "southeast_asia";
+  if (offset >= 4.5) return "central_asia";
+  if (offset >= 2) return "west_asia";
+  if (offset >= -2) return "europe_africa";
+  if (offset >= -7) return "north_america";
+  return "south_america";
+}
+
 const TRADING_REGION_KEYS = new Set<string>(TRADING_REGIONS.map((region) => region.key));
 
 const CITY_REGION_FALLBACK: Record<string, TradingRegionKey> = {