body {
            font-family: 'Arial', sans-serif;
            background-color: #f8f9fa;
            line-height: 1.6;
            padding: 20px;
        }

        .container {
            max-width: 800px;
            margin: 0 auto;
        }

        .header {
            background: linear-gradient(135deg, #FFAC1C 0%, #f3803a 100%);
            color: white;
            padding: 20px;
            border-radius: 10px;
            margin-bottom: 30px;
            text-align: center;
        }

        .header h1 {
            font-size: 28px;
            margin-bottom: 10px;
        }

        .back-link {
            display: inline-block;
            color: white;
            text-decoration: none;
            margin-bottom: 20px;
            padding: 8px 16px;
            background: rgba(255,255,255,0.2);
            border-radius: 5px;
            transition: background-color 0.3s;
        }

        .back-link:hover {
            background: rgba(255,255,255,0.3);
        }

        .order-container {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 30px;
            background: white;
            border-radius: 15px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
            overflow: hidden;
        }

        .book-info {
            padding: 30px;
            background: #f8f9fa;
        }

        .book-image {
            width: 100%;
            height: 400px;
            background: linear-gradient(135deg, #FFAC1C 0%, #f3803a 100%);
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 18px;
            font-weight: bold;
            margin-bottom: 20px;
        }

        .book-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            border-radius: 10px;
        }

        .book-title {
            font-size: 24px;
            font-weight: bold;
            margin-bottom: 10px;
            color: #333;
        }

        .book-author {
            color: #666;
            font-size: 18px;
            margin-bottom: 10px;
        }

        .book-category {
            background: #e3f2fd;
            color: #1976d2;
            padding: 6px 12px;
            border-radius: 15px;
            font-size: 14px;
            display: inline-block;
            margin-bottom: 15px;
        }

        .book-price {
            font-size: 32px;
            font-weight: bold;
            color: #4caf50;
            margin-bottom: 15px;
        }

        .book-description {
            color: #666;
            line-height: 1.6;
        }

        .order-form {
            padding: 30px;
        }

        .form-group {
            margin-bottom: 25px;
        }

        .form-group label {
            display: block;
            margin-bottom: 8px;
            font-weight: 600;
            color: #333;
        }

        .form-group input, .form-group textarea {
            width: 100%;
            padding: 15px;
            border: 2px solid #e1e5e9;
            border-radius: 8px;
            font-size: 16px;
            transition: border-color 0.3s;
        }

        .form-group input:focus, .form-group textarea:focus {
            outline: none;
            border-color: #667eea;
        }

        .form-group textarea {
            resize: vertical;
            min-height: 100px;
        }

        .quantity-group {
            display: flex;
            gap: 15px;
            align-items: end;
        }

        .quantity-group .form-group {
            flex: 1;
            margin-bottom: 0;
        }

        .total-price {
            background: #f8f9fa;
            padding: 15px;
            border-radius: 8px;
            margin-bottom: 25px;
            text-align: center;
        }

        .total-price .label {
            color: #666;
            font-size: 14px;
        }

        .total-price .amount {
            font-size: 24px;
            font-weight: bold;
            color: #4caf50;
        }

        .error {
            background: #fee;
            color: #c33;
            padding: 15px;
            border-radius: 8px;
            margin-bottom: 20px;
            border-left: 4px solid #c33;
        }

        .success {
            background: #efe;
            color: #2e7d32;
            padding: 15px;
            border-radius: 8px;
            margin-bottom: 20px;
            border-left: 4px solid #4caf50;
        }

        .order-btn {
            width: 100%;
            background: linear-gradient(135deg, #FFAC1C 0%, #f3803a 100%);
            color: white;
            border: none;
            padding: 18px;
            border-radius: 8px;
            font-size: 18px;
            font-weight: 600;
            cursor: pointer;
            transition: transform 0.2s;
        }

        .order-btn:hover {
            transform: translateY(-2px);
        }

        .order-btn:disabled {
            background: #ccc;
            cursor: not-allowed;
            transform: none;
        }

        @media (max-width: 768px) {
            .order-container {
                grid-template-columns: 1fr;
            }
            
            .book-info, .order-form {
                padding: 20px;
            }
            
            .book-image {
                height: 200px;
            }
            
            .quantity-group {
                flex-direction: column;
                gap: 0;
            }
            
            .quantity-group .form-group {
                margin-bottom: 25px;
            }
        }