:root {
            --primary: #4f46e5;
            --danger: #ef4444;
            --success: #22c55e;
            --bg: #f3f4f6;
            --register-bg: #fff3e0; 
        }
        body {
            font-family: Tahoma, sans-serif;
            background-color: var(--bg); 
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            margin: 0;
            transition: background-color 0.5s ease; 
        }
        .container {
            background: white;
            padding: 2rem;
            border-radius: 12px;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
            width: 100%;
            max-width: 400px;
            text-align: center;
        }
        h2 { margin-bottom: 1.5rem; color: #333; }
        .input-group { margin-bottom: 1rem; text-align: right; }
        input {
            width: 100%;
            padding: 10px;
            border: 1px solid #ddd;
            border-radius: 6px;
            box-sizing: border-box;
            font-family: inherit;
        }
        button {
            width: 100%;
            padding: 10px;
            border: none;
            border-radius: 6px;
            background-color: var(--primary);
            color: white;
            font-size: 1rem;
            cursor: pointer;
            transition: 0.3s;
        }
        button:hover { opacity: 0.9; }
        .toggle-btn {
            background: none;
            color: var(--primary);
            margin-top: 10px;
        }
        .toggle-btn:hover { text-decoration: underline; opacity: 1; }
        .alert {
            padding: 10px;
            border-radius: 6px;
            margin-bottom: 1rem;
            font-size: 0.9rem;
            display: none;
        }
        .alert.error { background-color: #fee2e2; color: var(--danger); }
        .alert.success { background-color: #dcfce7; color: var(--success); }
        
     
        .hidden { display: none; }