body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
            background-color: #f7f7f7;
        }
        header {
            background-color: #333;
            color: #fff;
            text-align: center;
            padding: 20px 0;
            margin-bottom: 20px;
        }
        .container {
            max-width: 600px;
            margin: 0 auto;
            padding: 0 20px;
        }
        form,
        .centre{
            background-color: #fff;
            padding: 20px;
            border-radius: 5px;
            box-shadow: 0 0 10px rgba(0,0,0,0.1);
            margin-bottom: 20px;
        }
        label {
            display: block;
            margin-bottom: 10px;
        }
        input[type="text"],
        input[type="password"],
        select {
            width: 100%;
            padding: 10px;
            margin-bottom: 20px;
            border: 1px solid #ccc;
            border-radius: 5px;
            box-sizing: border-box;
        }
        .btn {
            background-color: #333;
            color: #fff;
            border: none;
            padding: 10px 20px;
            border-radius: 5px;
            cursor: pointer;
        }
        .btn:hover {
            background-color: #555;
        }
        .pk {
            display: none;
        }