板塊輪動

1. Cloudflare 後台 → Workers & Pages → 你的 Worker → Edit code，把下方程式碼整段貼上，並把 ALLOW 改成你的 GitHub Pages 網域（只要 https://帳號.github.io，不含路徑）。
2. 回到 Worker → Settings → Variables and Secrets → Add，類型選 Secret：名稱 CMC_KEY 填 CoinMarketCap 金鑰；再新增 CG_KEY 填 CoinGecko 金鑰。
3. 按 Deploy。之後網頁只要填 Worker 網址就能用，換電腦也一樣。

// 金鑰優先用 Worker 的 Secret：CMC_KEY、CG_KEY（Settings → Variables and Secrets）；沒設就用網頁送來的金鑰
const ALLOW = ["https://你的帳號.github.io"]; // 改成你的 GitHub Pages 網域（不含路徑）
const ROUTES = {
  "/v2/cryptocurrency/quotes/latest": (env, h) => ["https://pro-api.coinmarketcap.com/v2/cryptocurrency/quotes/latest", { "X-CMC_PRO_API_KEY": env.CMC_KEY || h.get("X-CMC_PRO_API_KEY") || "" }],
  "/cg/coins/markets": (env, h) => ["https://api.coingecko.com/api/v3/coins/markets", { "x-cg-demo-api-key": env.CG_KEY || h.get("x-cg-demo-api-key") || "" }]
};
export default {
  async fetch(req, env) {
    const o = req.headers.get("Origin") || "";
    const cors = { "Access-Control-Allow-Origin": ALLOW.includes(o) ? o : ALLOW[0], "Access-Control-Allow-Methods": "GET, OPTIONS", "Access-Control-Allow-Headers": "X-CMC_PRO_API_KEY, x-cg-demo-api-key", "Vary": "Origin" };
    if (req.method === "OPTIONS") return new Response(null, { headers: cors });
    if (req.method !== "GET" || !ALLOW.includes(o)) return new Response("forbidden", { status: 403, headers: cors });
    const u = new URL(req.url), route = ROUTES[u.pathname];
    if (!route) return new Response("not allowed", { status: 404, headers: cors });
    const [target, auth] = route(env, req.headers);
    const r = await fetch(target + u.search, { headers: { ...auth, "Accept": "application/json" } });
    return new Response(r.body, { status: r.status, headers: { ...cors, "Content-Type": "application/json" } });
  }
};