diff --git a/lib/common/static/hedge_plan.js b/lib/common/static/hedge_plan.js
index 6576ba3..4c35a65 100644
--- a/lib/common/static/hedge_plan.js
+++ b/lib/common/static/hedge_plan.js
@@ -506,46 +506,50 @@
     return Number.isFinite(eth) && eth > 0 ? eth : 5;
   }
 
-  /** 按交易账户 USDT(买币+5%滑点)与合约账户永续杠杆算最大期权张数. */
+  /**
+   * 期权开仓最大张数:OKX 交易账户 USDT 共用.
+   * 每张开仓需:买币(权利金×1.05×指数) + 永续保证金(对冲名义÷杠杆);
+   * 选最大 N 时须保证扣完买币后剩余仍够永续保证金.
+   */
   function computeMaxSheets() {
     const ask = state.selected && Number(state.selected.ask);
     const ct = Number((state.selected && state.selected.ct_mult) || 0.01);
     const ratio = numInput("hp-opt-perp-ratio", 2);
-    const cs = Number((state.market && state.market.contract_size) || 0.01);
-    const mark = Number((state.market && (state.market.mark || state.market.index_px)) || indexPx() || 0);
+    const mark = Number(
+      (state.market && (state.market.mark || state.market.index_px)) || indexPx() || 0
+    );
     const lev = defaultPerpLeverage(state.underlying);
-    const tradingUsdt = Number(state.tradingUsdt != null ? state.tradingUsdt : state.tradingUsdc);
-    const perpAvail = Number((state.market && state.market.available_usdt) || 0);
-    if (!(ask > 0) || !(ct > 0) || !(ratio > 0) || !(cs > 0) || !(mark > 0) || !(lev > 0)) {
+    const tradingUsdt = Number(
+      state.tradingUsdt != null ? state.tradingUsdt : state.tradingUsdc
+    );
+    if (!(ask > 0) || !(ct > 0) || !(ratio > 0) || !(mark > 0) || !(lev > 0)) {
       return null;
     }
-    // 买币:权利金币×1.05×指数 ≈ 所需 USDT
-    const coinPerSheet = ask * ct;
-    const usdtPerSheet = coinPerSheet * 1.05 * mark;
-    let maxByOpt = Infinity;
-    if (tradingUsdt > 0 && usdtPerSheet > 0) {
-      maxByOpt = Math.floor(tradingUsdt / usdtPerSheet + 1e-12);
+    if (!(tradingUsdt > 0)) {
+      return {
+        max_sheets: 0,
+        lev: lev,
+        trading_usdt: tradingUsdt,
+        buy_usdt_per_sheet: 0,
+        margin_per_sheet: 0,
+        total_per_sheet: 0,
+      };
     }
-    // 永续:名义 = 保证金×杠杆; 永续币 = 期权币/比例; 合约张 = 永续币/cs
-    // 期权张 n → 永续名义 = (n*ct/ratio)*mark ≤ avail*lev
-    let maxByPerp = Infinity;
-    if (perpAvail > 0) {
-      const maxPerpNotional = perpAvail * lev;
-      const notionalPerSheet = (ct / ratio) * mark;
-      if (notionalPerSheet > 0) {
-        maxByPerp = Math.floor(maxPerpNotional / notionalPerSheet + 1e-12);
-      }
-    }
-    const maxSheets = Math.max(0, Math.min(maxByOpt, maxByPerp));
-    if (!(maxSheets > 0) && !(tradingUsdt > 0) && !(perpAvail > 0)) return null;
+    // 买币 USDT/张 = 权利金币 × 1.05 × 指数
+    const buyUsdtPerSheet = ask * ct * 1.05 * mark;
+    // 永续名义/张 = (期权币/比例)×指数; 保证金 = 名义÷杠杆
+    const perpNotionalPerSheet = (ct / ratio) * mark;
+    const marginPerSheet = perpNotionalPerSheet / lev;
+    const totalPerSheet = buyUsdtPerSheet + marginPerSheet;
+    if (!(totalPerSheet > 0)) return null;
+    const maxSheets = Math.max(0, Math.floor(tradingUsdt / totalPerSheet + 1e-12));
     return {
       max_sheets: maxSheets,
-      max_by_opt: Number.isFinite(maxByOpt) ? maxByOpt : null,
-      max_by_perp: Number.isFinite(maxByPerp) ? maxByPerp : null,
       lev: lev,
       trading_usdt: tradingUsdt,
-      perp_avail: perpAvail,
-      usdt_per_sheet: usdtPerSheet,
+      buy_usdt_per_sheet: buyUsdtPerSheet,
+      margin_per_sheet: marginPerSheet,
+      total_per_sheet: totalPerSheet,
     };
   }
 
@@ -556,23 +560,37 @@
     const sized = currentOpSizing();
     const coin = (state.underlying || "ETH").toUpperCase();
     const lev = defaultPerpLeverage(state.underlying);
+    const mark = Number(
+      (state.market && (state.market.mark || state.market.index_px)) || indexPx() || 0
+    );
     if (maxEl) {
       if (maxInfo) {
         maxEl.innerHTML =
-          "最大约 <strong>" +
+          "期权开仓最大 <strong>" +
           maxInfo.max_sheets +
-          "</strong> 张 · 永续杠杆 " +
-          lev +
-          "x(env) · 交易 USDT " +
+          "</strong> 张 · 交易 USDT " +
           fmt(maxInfo.trading_usdt, 2) +
-          " · 合约可用 " +
-          fmt(maxInfo.perp_avail, 2);
+          " · 每张约买币 " +
+          fmt(maxInfo.buy_usdt_per_sheet, 2) +
+          " + 永续保证金 " +
+          fmt(maxInfo.margin_per_sheet, 2) +
+          " (杠杆 " +
+          lev +
+          "x)";
       } else {
-        maxEl.textContent = "选择期权并刷新行情后显示最大开仓张数(交易账户买币+永续杠杆)";
+        maxEl.textContent =
+          "选择期权并刷新后显示:期权开仓最大张数(扣买币后剩余须够永续保证金)";
       }
     }
     if (perpEl) {
       if (sized) {
+        const buyUsdt = sized.premium_est * 1.05 * (mark > 0 ? mark : 0);
+        const marginUsdt =
+          sized.perp_qty * (mark > 0 ? mark : 0) / (lev > 0 ? lev : 1);
+        const remain =
+          Number(state.tradingUsdt != null ? state.tradingUsdt : state.tradingUsdc) -
+          buyUsdt;
+        const marginOk = remain + 1e-9 >= marginUsdt;
         perpEl.innerHTML =
           "永续自动开 <strong>" +
           fmt(sized.perp_qty, 4) +
@@ -584,7 +602,14 @@
           fmt(sized.premium_est * 1.05, 4) +
           " " +
           coin +
-          "(含5%滑点)";
+          "(≈" +
+          fmt(buyUsdt, 2) +
+          " U含5%) · 扣后剩 " +
+          fmt(remain, 2) +
+          " U · 永续保证金约 " +
+          fmt(marginUsdt, 2) +
+          " U" +
+          (marginOk ? "" : ' <span class="is-err">不足</span>');
       } else {
         perpEl.textContent = "永续开仓 — (填张数并选择期权后按比例自动算)";
       }