function doPost(e) {
  var lock = LockService.getScriptLock();
  lock.tryLock(10000);
  try {
    var doc = SpreadsheetApp.getActiveSpreadsheet();
    var sheet = doc.getSheetByName('Package_Logs');
    if (!sheet) {
      sheet = doc.insertSheet('Package_Logs');
      sheet.appendRow([
        "Timestamp", "Quote ID", "Client Name", "Pax Summary", 
        "Hotels Summary", "Transport Sectors", "Total Cost (PKR)", 
        "Markup %", "Net Profit (PKR)", "Total Selling (PKR)", 
        "Adult Price (PKR)", "CWB Price (PKR)", "CNB Price (PKR)", "Infant Price (PKR)"
      ]);
      // Format headers
      sheet.getRange(1, 1, 1, 14).setBackground("#064E3B").setFontColor("#FFFFFF").setFontWeight("bold");
    }
    var d = JSON.parse(e.postData.contents);
    sheet.appendRow([
      new Date(), d.quoteId, d.clientName, d.paxSummary, 
      d.hotelsSummary, d.transportSummary, d.totalCostPKR, 
      d.markupPercent, d.netProfitPKR, d.totalSellingPKR, 
      d.adultPricePKR, d.cwbPricePKR, d.cnbPricePKR, d.infantPricePKR
    ]);
    return ContentService.createTextOutput(JSON.stringify({ result: "success" })).setMimeType(ContentService.MimeType.JSON);
  } catch (err) {
    return ContentService.createTextOutput(JSON.stringify({ result: "error", error: err.toString() })).setMimeType(ContentService.MimeType.JSON);
  } finally {
    lock.releaseLock();
  }
}