diff --git a/dea.service b/dea.service
index 6f52803..ea3d251 100644
--- a/dea.service
+++ b/dea.service
@@ -1,12 +1,29 @@
+# =============================================================
+# dea.service — Difference Equation Analyzer systemd 服務設定
+# =============================================================
+#
+# 部署步驟：
+#   1. 修改 User / WorkingDirectory / 路徑
+#   2. sudo cp dea.service /etc/systemd/system/
+#   3. sudo systemctl daemon-reload
+#   4. sudo systemctl enable --now dea
+#   5. sudo systemctl restart dea.service
+#
+# 防火牆（若手機或其他裝置無法連線）：
+#   sudo ufw allow 8000
+#
+# =============================================================
+
 [Unit]
 Description=Difference Equation Analyzer FastAPI Server
 After=network.target
 
 [Service]
-User=wisetop
-WorkingDirectory=/home/wisetop/diff-eq-analyzer
-Environment="PATH=/home/wisetop/diff-eq-analyzer/.venv/bin"
-ExecStart=/home/wisetop/diff-eq-analyzer/.venv/bin/uvicorn dea_api:app --host 0.0.0.0 --port 8000 --ssl-keyfile=/home/wisetop/diff-eq-analyzer/certs/key.pem --ssl-certfile=/home/wisetop/diff-eq-analyzer/certs/cert.pem
+User=roy
+WorkingDirectory=/home/roy/zData/WTPCode/bodeplot
+Environment="PATH=/home/roy/zData/WTPCode/bodeplot/.venv/bin"
+ExecStart=/home/roy/zData/WTPCode/bodeplot/.venv/bin/uvicorn dea_api:app --host 0.0.0.0 --port 8000 --ssl-keyfile=/home/roy/zData/WTPCode/bodeplot/certs/key.pem --ssl-certfile=/home/roy/zData/WTPCode/bodeplot/certs/cert.pem
+
 Restart=always
 RestartSec=3