diff --git a/diagnostic/server.js b/diagnostic/server.js
index dd546fb..7840935 100644
--- a/diagnostic/server.js
+++ b/diagnostic/server.js
@@ -493,8 +493,8 @@ function startProxyLogin() {
   log("info", "proxy", "Starte Claude Login im Proxy-Container...");
   broadcast({ type: "login_status", status: "starting" });
 
-  // TERM=dumb und NO_COLOR=1 deaktivieren die TUI und Farben
-  dockerExecStreaming("aria-proxy", "TERM=dumb NO_COLOR=1 CI=1 claude login 2>&1",
+  // TERM=dumb deaktiviert TUI, echo 1 waehlt Dark Mode bei Theme-Auswahl
+  dockerExecStreaming("aria-proxy", "echo 1 | TERM=dumb NO_COLOR=1 CI=1 claude login 2>&1",
     (chunk) => {
       const clean = stripAnsi(chunk).trim();
       if (!clean) return;