body {
            background: #fff;
            color: #000;
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
        }
        .container {
            max-width: 700px;
            margin: 30px auto;
            background: #fff;
            border-radius: 10px;
            padding: 30px;
            box-shadow: 0 0 10px #e53935;
        }
        h1, h2 {
            color: #000;
            text-align: center;
        }
        label {
            color: #fff;
            font-weight: bold;
        }
        input, select, button {
            padding: 8px;
            margin: 8px 0;
            border-radius: 5px;
            border: none;
            font-size: 16px;
        }
        input[type="text"], input[type="number"] {
            width: 100%;
            background: #fff;
            color: #000;
            border: 1px solid #e53935;
        }
        select {
            width: 100%;
            background: #fff;
            color: #111;
            border: 1px solid #e53935;
        }
        button {
            background: #e53935;
            color: #fff;
            cursor: pointer;
            font-weight: bold;
            transition: background 0.2s;
        }
        button:hover {
            background: #fff;
            color: #e53935;
            border: 1px solid #e53935;
        }
        .number-chart {
            display: flex;
            flex-wrap: wrap;
            gap: 6px;
            margin: 20px 0;
            justify-content: center;
        }
        .number-btn {
            width: 40px;
            height: 40px;
            background: #fff;
            color: #111;
            border: 2px solid #e53935;
            border-radius: 50%;
            font-weight: bold;
            font-size: 16px;
            cursor: pointer;
            transition: background 0.2s, color 0.2s;
        }
        .number-btn.selected {
            background: #e53935;
            color: #fff;
            border: 2px solid #fff;
            cursor: not-allowed;
        }
        .number-btn.sold {
            background: #111;
            color: #fff;
            border: 2px solid #fff;
            cursor: not-allowed;
            opacity: 0.5;
        }
        .vertical-list {
            display: flex;
            flex-direction: column;
            align-items: flex-start;
            margin: 10px 0;
            color: #111;
            font-size: 18px;
        }
        .message {
            color: #e53935;
            font-weight: bold;
            margin: 10px 0;
            text-align: center;
        }
        .invoice {
            background: #fff;
            border: 2px solid #e53935;
            border-radius: 8px;
            padding: 15px;
            margin-top: 20px;
            color: #111;
        }
        .invoice h3 {
            color: #e53935;
            margin-top: 0;
        }
        .invoice-list {
            margin-top: 20px;
        }
        .invoice-list .invoice {
            margin-bottom: 15px;
        }