diff --git a/src/components/Header.tsx b/src/components/Header.tsx
new file mode 100644
index 0000000..c19cdc6
--- /dev/null
+++ b/src/components/Header.tsx
@@ -0,0 +1,128 @@
+import { useState, useEffect } from "react";
+import { Link } from "react-router-dom";
+import { Button } from "@/components/ui/button";
+import { Sheet, SheetContent, SheetTrigger } from "@/components/ui/sheet";
+import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogDescription, DialogTrigger } from "@/components/ui/dialog";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { Menu, GraduationCap } from "lucide-react";
+import { ThemeToggle } from "@/components/ThemeToggle";
+import { useAuth } from "@/hooks/use-tygarun";
+import { toast } from "sonner";
+
+function AuthDialog({ trigger }: { trigger: React.ReactNode }) {
+  const { signin, signup, isSignedIn, signout, user } = useAuth();
+  const [open, setOpen] = useState(false);
+  const [mode, setMode] = useState<"signin" | "signup">("signin");
+  const [email, setEmail] = useState("");
+  const [password, setPassword] = useState("");
+  const [busy, setBusy] = useState(false);
+
+  if (isSignedIn) {
+    return (
+      <Button variant="ghost" size="sm" className="rounded-full" onClick={() => { signout(); toast.success("Signed out."); }}>
+        {user?.name || user?.email || "Account"} · Sign Out
+      </Button>
+    );
+  }
+
+  const submit = async (e: React.FormEvent) => {
+    e.preventDefault();
+    setBusy(true);
+    try {
+      if (mode === "signup") await signup({ email, password });
+      else await signin(email, password);
+      toast.success(mode === "signup" ? "Account created!" : "Welcome back!");
+      setOpen(false);
+    } catch { toast.error("Authentication failed. Please try again."); }
+    finally { setBusy(false); }
+  };
+
+  return (
+    <Dialog open={open} onOpenChange={setOpen}>
+      <DialogTrigger asChild>{trigger}</DialogTrigger>
+      <DialogContent className="sm:max-w-md">
+        <DialogHeader>
+          <DialogTitle>{mode === "signup" ? "Create your account" : "Sign in"}</DialogTitle>
+          <DialogDescription>{mode === "signup" ? "Start learning in minutes." : "Access your courses and progress."}</DialogDescription>
+        </DialogHeader>
+        <form onSubmit={submit} className="space-y-4">
+          <div className="space-y-2">
+            <Label htmlFor="auth-email">Email</Label>
+            <Input id="auth-email" type="email" value={email} onChange={(e) => setEmail(e.target.value)} placeholder="you@example.com" required />
+          </div>
+          <div className="space-y-2">
+            <Label htmlFor="auth-password">Password</Label>
+            <Input id="auth-password" type="password" value={password} onChange={(e) => setPassword(e.target.value)} placeholder="••••••••" required />
+          </div>
+          <Button type="submit" disabled={busy} className="w-full bg-indigo-600 hover:bg-indigo-700 text-white rounded-full">
+            {busy ? "Please wait…" : mode === "signup" ? "Create Account" : "Sign In"}
+          </Button>
+        </form>
+        <button type="button" className="text-sm text-indigo-600 hover:underline" onClick={() => setMode(mode === "signup" ? "signin" : "signup")}>
+          {mode === "signup" ? "Already have an account? Sign in" : "New here? Create an account"}
+        </button>
+      </DialogContent>
+    </Dialog>
+  );
+}
+
+export default function Header() {
+  const [open, setOpen] = useState(false);
+  const [scrolled, setScrolled] = useState(false);
+
+  useEffect(() => {
+    const fn = () => setScrolled(window.scrollY > 20);
+    window.addEventListener("scroll", fn);
+    return () => window.removeEventListener("scroll", fn);
+  }, []);
+
+  const links = [
+    { label: "Courses", to: "/courses" },
+    { label: "Instructors", to: "/instructors" },
+    { label: "Pricing", to: "/courses" },
+    { label: "Contact", to: "/contact" },
+  ];
+
+  return (
+    <header className={`fixed top-0 inset-x-0 z-50 transition-all duration-300 \${scrolled ? "bg-white/90 dark:bg-slate-950/95 backdrop-blur-lg border-b border-slate-200 dark:border-slate-800 shadow-sm" : "bg-transparent"}`}>
+      <div className="mx-auto max-w-7xl flex items-center justify-between px-6 py-4">
+        <Link to="/" className="flex items-center gap-2 group">
+          <div className="relative">
+            <GraduationCap className={`h-7 w-7 transition-colors \${scrolled ? "text-indigo-600" : "text-white"}`} />
+          </div>
+          <span className={`text-lg font-bold tracking-tight transition-colors \${scrolled ? "text-slate-900 dark:text-white" : "text-white"}`}>Luminar Academy</span>
+        </Link>
+        <nav className="hidden md:flex items-center gap-8">
+          {links.map((l) => (
+            <Link key={l.to} to={l.to} className={`text-sm font-medium transition-colors hover:text-indigo-500 \${scrolled ? "text-slate-600 dark:text-slate-300" : "text-white/90"}`}>{l.label}</Link>
+          ))}
+        </nav>
+        <div className="hidden md:flex items-center gap-3">
+          <ThemeToggle />
+          <AuthDialog trigger={<Button variant="ghost" size="sm" className={`rounded-full \${scrolled ? "text-slate-700 dark:text-slate-200" : "text-white hover:text-white"}`}>Sign In</Button>} />
+          <Button asChild size="sm" className="bg-indigo-600 hover:bg-indigo-700 text-white rounded-full px-6 shadow-lg shadow-indigo-500/20 active:scale-[0.97] transition-all">
+            <Link to="/courses">Enroll Now</Link>
+          </Button>
+        </div>
+        <Sheet open={open} onOpenChange={setOpen}>
+          <SheetTrigger asChild className="md:hidden">
+            <Button variant="ghost" size="icon" className={`\${scrolled ? "text-slate-900 dark:text-white" : "text-white"}`}><Menu className="h-5 w-5" /></Button>
+          </SheetTrigger>
+          <SheetContent side="right" className="w-72 bg-white dark:bg-slate-950 border-slate-200 dark:border-slate-800">
+            <nav className="mt-8 flex flex-col gap-4">
+              {links.map((l) => (
+                <Link key={l.to} to={l.to} className="text-lg font-medium text-slate-700 dark:text-slate-200 hover:text-indigo-500 transition-colors" onClick={() => setOpen(false)}>{l.label}</Link>
+              ))}
+              <Button asChild className="mt-4 w-full bg-indigo-600 hover:bg-indigo-700 text-white rounded-full active:scale-[0.97] transition-all">
+                <Link to="/courses" onClick={() => setOpen(false)}>Enroll Now</Link>
+              </Button>
+              <AuthDialog trigger={<Button variant="outline" className="w-full rounded-full">Sign In</Button>} />
+              <ThemeToggle />
+            </nav>
+          </SheetContent>
+        </Sheet>
+      </div>
+    </header>
+  );
+}
\ No newline at end of file