diff --git a/src/app/(auth)/sign-in/components/login-form-1.tsx b/src/app/(auth)/sign-in/components/login-form-1.tsx
index 4a8ea78..cf94878 100644
--- a/src/app/(auth)/sign-in/components/login-form-1.tsx
+++ b/src/app/(auth)/sign-in/components/login-form-1.tsx
@@ -1,8 +1,8 @@
 "use client";
 
 import Link from "next/link";
-import { useActionState } from "react";
-import { Loader2 } from "lucide-react";
+import { useActionState, useState } from "react";
+import { FlaskConical, Loader2, Stethoscope } from "lucide-react";
 
 import { Button } from "@/components/ui/button";
 import { Card, CardContent } from "@/components/ui/card";
@@ -13,11 +13,14 @@ import { cn } from "@/lib/utils";
 import { signInAction } from "@/lib/appwrite/auth-actions";
 import { initialAuthState } from "@/lib/appwrite/auth-types";
 
+type Kind = "clinic" | "lab";
+
 export function LoginForm1({
   className,
   inviteCode,
   ...props
 }: React.ComponentProps<"div"> & { inviteCode?: string }) {
+  const [kind, setKind] = useState<Kind>("clinic");
   const [state, formAction, isPending] = useActionState(signInAction, initialAuthState);
 
   return (
@@ -26,6 +29,7 @@ export function LoginForm1({
         <CardContent className="grid p-0 md:grid-cols-2">
           <form action={formAction} className="p-6 md:p-10">
             {inviteCode && <input type="hidden" name="inviteCode" value={inviteCode} />}
+            <input type="hidden" name="kind" value={kind} />
             <div className="flex flex-col gap-6">
               <div className="flex justify-center">
                 <Link href="/" className="flex items-center gap-2 font-medium">
@@ -45,10 +49,14 @@ export function LoginForm1({
               <div className="flex flex-col items-center text-center">
                 <h1 className="text-2xl font-bold tracking-tight">Tekrar hoş geldiniz</h1>
                 <p className="text-muted-foreground text-sm text-balance mt-1">
-                  Hesabınıza giriş yaparak işletmenizi yönetmeye devam edin
+                  Hesabınıza giriş yapın
                 </p>
               </div>
 
+              {!inviteCode && (
+                <KindPill value={kind} onChange={setKind} disabled={isPending} />
+              )}
+
               <div className="grid gap-3">
                 <Label htmlFor="email">Email</Label>
                 <Input
@@ -128,6 +136,72 @@ export function LoginForm1({
   );
 }
 
+function KindPill({
+  value,
+  onChange,
+  disabled,
+}: {
+  value: Kind;
+  onChange: (next: Kind) => void;
+  disabled?: boolean;
+}) {
+  return (
+    <div
+      role="radiogroup"
+      aria-label="Hesap türü"
+      className="bg-muted text-muted-foreground inline-flex w-full items-center gap-1 rounded-full border p-1"
+    >
+      <PillButton
+        active={value === "clinic"}
+        onClick={() => onChange("clinic")}
+        disabled={disabled}
+      >
+        <Stethoscope className="size-4" />
+        Klinik
+      </PillButton>
+      <PillButton
+        active={value === "lab"}
+        onClick={() => onChange("lab")}
+        disabled={disabled}
+      >
+        <FlaskConical className="size-4" />
+        Laboratuvar
+      </PillButton>
+    </div>
+  );
+}
+
+function PillButton({
+  active,
+  onClick,
+  disabled,
+  children,
+}: {
+  active: boolean;
+  onClick: () => void;
+  disabled?: boolean;
+  children: React.ReactNode;
+}) {
+  return (
+    <button
+      type="button"
+      role="radio"
+      aria-checked={active}
+      onClick={onClick}
+      disabled={disabled}
+      className={cn(
+        "flex flex-1 items-center justify-center gap-1.5 rounded-full px-3 py-1.5 text-sm font-medium transition-colors",
+        active
+          ? "bg-background text-foreground shadow-sm"
+          : "hover:text-foreground",
+        disabled && "cursor-not-allowed opacity-60",
+      )}
+    >
+      {children}
+    </button>
+  );
+}
+
 function BrandPanel() {
   return (
     <div className="bg-primary text-primary-foreground relative hidden md:flex md:flex-col md:justify-between overflow-hidden p-10">
@@ -157,10 +231,10 @@ function BrandPanel() {
 
       <div className="relative z-10 flex flex-col gap-3">
         <h2 className="text-3xl font-semibold leading-tight">
-          Müşteriden faturaya, tek panelden işletmenizi yönetin.
+          Klinik ve laboratuvar tek panelde.
         </h2>
         <p className="text-primary-foreground/80 text-sm">
-          Müşteriler, hizmetler, takvim, görevler ve finans — hepsi tek yerde, multi-tenant ve ekibinize özel.
+          İş yayınla, taranan dosyaları paylaş, protez aşamalarını adım adım takip et — finansal akışla birlikte.
         </p>
         <div className="text-primary-foreground/70 mt-4 text-xs">Kovak Yazılım tarafından</div>
       </div>
diff --git a/src/lib/appwrite/auth-actions.ts b/src/lib/appwrite/auth-actions.ts
index 9dd5c7d..bbdd5a9 100644
--- a/src/lib/appwrite/auth-actions.ts
+++ b/src/lib/appwrite/auth-actions.ts
@@ -2,9 +2,11 @@
 
 import { cookies } from "next/headers";
 import { redirect } from "next/navigation";
-import { AppwriteException, ID } from "node-appwrite";
+import { AppwriteException, ID, Query } from "node-appwrite";
 
 import { APPWRITE_SESSION_COOKIE, createAdminClient, createSessionClient } from "./server";
+import { DATABASE_ID, TABLES, type TenantKind, type TenantSettings } from "./schema";
+import { ACTIVE_TENANT_COOKIE } from "./tenant-types";
 import type { AuthState } from "./auth-types";
 
 function appwriteError(e: unknown): string {
@@ -38,23 +40,90 @@ async function setSessionCookie(secret: string, expire: string) {
   });
 }
 
+async function setActiveTenantCookie(tenantId: string) {
+  (await cookies()).set(ACTIVE_TENANT_COOKIE, tenantId, {
+    path: "/",
+    httpOnly: true,
+    sameSite: "strict",
+    secure: process.env.NODE_ENV === "production",
+    maxAge: 60 * 60 * 24 * 365,
+  });
+}
+
+async function pickTenantIdByKind(userId: string, kind: TenantKind): Promise<string | null> {
+  const { users, tablesDB } = createAdminClient();
+  const memberships = await users.listMemberships(userId);
+  const teamIds = memberships.memberships.map((m) => m.teamId);
+  if (teamIds.length === 0) return null;
+
+  const result = await tablesDB.listRows({
+    databaseId: DATABASE_ID,
+    tableId: TABLES.tenantSettings,
+    queries: [
+      Query.equal("tenantId", teamIds),
+      Query.equal("kind", kind),
+      Query.limit(1),
+    ],
+  });
+  const row = result.rows[0] as unknown as TenantSettings | undefined;
+  return row?.tenantId ?? null;
+}
+
 export async function signInAction(_prev: AuthState, formData: FormData): Promise<AuthState> {
   const email = String(formData.get("email") ?? "").trim();
   const password = String(formData.get("password") ?? "");
   const inviteCode = String(formData.get("inviteCode") ?? "").trim();
+  const rawKind = String(formData.get("kind") ?? "").trim();
+  const kind: TenantKind | null =
+    rawKind === "lab" || rawKind === "clinic" ? rawKind : null;
 
   if (!email || !password) {
     return { ok: false, error: "Email ve şifre zorunlu." };
   }
 
+  let sessionUserId: string | null = null;
+  let sessionId: string | null = null;
   try {
     const { account } = createAdminClient();
     const session = await account.createEmailPasswordSession(email, password);
+    sessionUserId = session.userId;
+    sessionId = session.$id;
     await setSessionCookie(session.secret, session.expire);
   } catch (e) {
     return { ok: false, error: appwriteError(e) };
   }
 
+  // Invite flow short-circuits the kind check — invite code drives team membership
+  if (!inviteCode && kind && sessionUserId) {
+    const matchedTenantId = await pickTenantIdByKind(sessionUserId, kind);
+    if (!matchedTenantId) {
+      // Roll back session: user has no tenant of the requested kind
+      try {
+        const { users } = createAdminClient();
+        if (sessionId) await users.deleteSession(sessionUserId, sessionId);
+      } catch {
+        /* best-effort */
+      }
+      (await cookies()).delete(APPWRITE_SESSION_COOKIE);
+      const label = kind === "lab" ? "laboratuvar" : "klinik";
+      return {
+        ok: false,
+        error: `Bu hesap için ${label} kaydı bulunamadı. Diğer hesap türünü seçin veya yeni çalışma alanı oluşturun.`,
+      };
+    }
+    await setActiveTenantCookie(matchedTenantId);
+    try {
+      const { users } = createAdminClient();
+      const user = await users.get(sessionUserId);
+      await users.updatePrefs(sessionUserId, {
+        ...(user.prefs ?? {}),
+        activeTenant: matchedTenantId,
+      });
+    } catch {
+      /* best-effort */
+    }
+  }
+
   redirect(inviteCode ? `/d/${inviteCode}` : "/dashboard");
 }