* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: "Sarabun", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
            line-height: 1.6;
            color: #1a202c;
            background: #f7fafc;
            min-height: 100vh;
            padding: 1rem;
        }

        .container {
            max-width: 700px;
            margin: 0 auto;
            background: #ffffff;
            border-radius: 12px;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
            border: 1px solid #e2e8f0;
            overflow: hidden;
            animation: fadeInUp 0.4s ease-out;
        }

        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .header {
            background: #2d3748;
            padding: 2rem;
            text-align: center;
            color: white;
            border-bottom: 1px solid #e2e8f0;
        }

        h1 {
            font-size: clamp(1.5rem, 4vw, 2.2rem);
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: white;
        }

        .countdown {
            font-size: 0.9rem;
            opacity: 0.8;
            font-weight: 400;
        }

        .content {
            padding: 2rem;
        }

        .image-container {
            position: relative;
            margin-bottom: 1.5rem;
            border-radius: 8px;
            overflow: hidden;
            border: 1px solid #e2e8f0;
        }

        img {
            width: 100%;
            height: auto;
            display: block;
        }

        .promotion {
            background: #2b6cb0;
            color: white;
            padding: 1rem;
            border-radius: 6px;
            font-weight: 500;
            text-align: center;
            margin-bottom: 1.5rem;
            font-size: 1rem;
            border: 1px solid #2c5282;
        }

        .description {
            font-size: 1rem;
            color: #4a5568;
            margin-bottom: 2rem;
            line-height: 1.7;
        }

        .cta-container {
            text-align: center;
            margin-bottom: 1rem;
        }

        .buy-link {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: #2d3748;
            color: white;
            padding: 1rem 2rem;
            border-radius: 6px;
            text-decoration: none;
            font-weight: 500;
            font-size: 1rem;
            transition: all 0.2s ease;
            border: 1px solid #2d3748;
            min-width: 200px;
        }

        .buy-link:hover {
            background: #1a202c;
            border-color: #1a202c;
        }

        .buy-link:active {
            transform: translateY(0);
        }

        .loading-text {
            font-size: 0.9rem;
            color: #6b7280;
            margin-top: 1rem;
            text-align: center;
        }

        /* Spinner Styles */
        .spinner-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.8);
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            z-index: 9999;
            opacity: 0;
            animation: fadeIn 0.3s ease-out forwards;
        }

        @keyframes fadeIn {
            to { opacity: 1; }
        }

        .spinner {
            width: 60px;
            height: 60px;
            border: 4px solid rgba(255, 255, 255, 0.3);
            border-top-color: #10b981;
            border-radius: 50%;
            animation: spin 1s linear infinite;
            margin-bottom: 1rem;
        }

        @keyframes spin {
            to { transform: rotate(360deg); }
        }

        .spinner-text {
            color: white;
            font-size: 1rem;
            font-weight: 400;
        }

        /* Responsive Design */
        @media (max-width: 768px) {
            body {
                padding: 0.5rem;
            }

            .container {
                margin: 1rem auto;
                border-radius: 16px;
            }

            .header {
                padding: 1.5rem;
            }

            .content {
                padding: 1.5rem;
            }

            .buy-link {
                width: 100%;
                padding: 1.2rem;
                font-size: 1.2rem;
            }
        }

        @media (max-width: 480px) {
            .container {
                margin: 0.5rem auto;
                border-radius: 12px;
            }

            .header {
                padding: 1rem;
            }

            .content {
                padding: 1rem;
            }

            .promotion {
                font-size: 1rem;
                padding: 0.8rem;
            }

            .description {
                font-size: 0.95rem;
            }
        }

        /* Dark mode support */
        @media (prefers-color-scheme: dark) {
            .container {
                background: rgba(26, 32, 44, 0.95);
                color: #e2e8f0;
            }

            .description {
                color: #a0aec0;
            }

            .loading-text {
                color: #9ca3af;
            }
        }

        /* Accessibility improvements */
        @media (prefers-reduced-motion: reduce) {
            * {
                animation-duration: 0.01ms !important;
                animation-iteration-count: 1 !important;
                transition-duration: 0.01ms !important;
            }
        }

        /* Focus styles for accessibility */
        .buy-link:focus {
            outline: 2px solid #4299e1;
            outline-offset: 2px;
        }