generate a css code for following code; <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Login - Beauty Salon</title>
<link rel="stylesheet" href="styles.css">
</head>
<body>
<header>
<div class="logo">Beauty Salon</div>
<nav>
<ul>
<li><a href="index.html">Home</a></li>
<li><a href="login.html">Login</a></li>
</ul>
</nav>
</header>
<main class="auth-container">
<div class="auth-tabs">
<button class="tab-btn active" data-tab="user">User Login</button>
<button class="tab-btn" data-tab="admin">Admin Login</button>
</div>
<div class="auth-form" id="user-form">
<h2>User Login</h2>
<form id="user-login">
<div class="form-group">
<label for="user-email">Email</label>
<input type="email" id="user-email" required>
</div>
<div class="form-group">
<label for="user-password">Password</label>
<input type="password" id="user-password" required>
</div>
<button type="submit" class="btn">Login</button>
<p>Don't have an account? <a href="signup.html">Sign up</a></p>
</form>
</div>
<div class="auth-form hidden" id="admin-form">
<h2>Admin Login</h2>
<form id="admin-login">
<div class="form-group">
<label for="admin-email">Email</label>
<input type="email" id="admin-email" required>
</div>
<div class="form-group">
<label for="admin-password">Password</label>
<input type="password" id="admin-password" required>
</div>
<button type="submit" class="btn">Login</button>
</form>
</div>
</main>
<script src="script.js"></script>
</body>
</html>