:root {
            --primary-color: #4361ee;
            --primary-dark: #3a56d4;
            --secondary-color: #3f37c9;
            --text-color: #2b2d42;
            --light-gray: #f8f9fa;
            --medium-gray: #e9ecef;
            --dark-gray: #6c757d;
            --white: #ffffff;
            --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            --border-radius: 8px;
        }

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

        body {
            font-family: 'Inter', sans-serif;
            color: var(--text-color);
            background-color: var(--light-gray);
            line-height: 1.6;
        }

        .app-container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 20px;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }

        .app-header {
            text-align: center;
            margin-bottom: 30px;
        }

        .app-header h1 {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
        }

        .subtitle {
            color: var(--dark-gray);
            font-size: 1.1rem;
        }

        .app-content {
            display: grid;
            grid-template-columns: 1fr 1fr 1fr;
            gap: 30px;
            flex: 1;
        }

        .upload-section {
            display: flex;
            flex-direction: column;
            gap: 20px;
        }

        .drop-zone {
            border: 2px dashed var(--dark-gray);
            border-radius: var(--border-radius);
            padding: 40px 20px;
            text-align: center;
            cursor: pointer;
            transition: all 0.3s ease;
            background-color: var(--white);
            box-shadow: var(--shadow);
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 15px;
        }

        .drop-zone i {
            font-size: 3rem;
            color: var(--primary-color);
        }

        .drop-zone h3 {
            font-size: 1.3rem;
            color: var(--text-color);
        }

        .drop-zone p {
            color: var(--dark-gray);
        }

        .drop-zone:hover, .drop-zone.active {
            border-color: var(--primary-color);
            background-color: rgba(67, 97, 238, 0.05);
        }

        .drop-zone input {
            display: none;
        }

        .file-info {
            padding: 15px;
            background-color: var(--white);
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            display: none;
        }

        .file-info.active {
            display: block;
        }

        .watermark-options {
            background-color: var(--white);
            padding: 25px;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
        }

        .watermark-options h2 {
            margin-bottom: 20px;
            font-size: 1.5rem;
            color: var(--primary-color);
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .preview-section {
            background-color: var(--white);
            padding: 25px;
            border-radius: var(--border-radius);
            box-shadow: var(--shadow);
            display: flex;
            flex-direction: column;
        }

        .preview-section h2 {
            margin-bottom: 20px;
            font-size: 1.5rem;
            color: var(--primary-color);
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .preview-container {
            flex: 1;
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 400px;
            background-color: var(--light-gray);
            border-radius: var(--border-radius);
            position: relative;
            padding: 20px;
        }

        .paper-preview {
            background-color: white;
            box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
            border-radius: 4px;
            position: relative;
            overflow: hidden;
        }

        .paper-preview.short {
            width: 310px;
            height: 397px;
        }

        .paper-preview.long {
            width: 310px;
            height: 420px;
        }

        .watermark-text {
            position: absolute;
            font-weight: bold;
            user-select: none;
            pointer-events: none;
            transform-origin: center;
            white-space: nowrap;
        }

        .paper-type-selector {
            display: flex;
            gap: 10px;
            margin-bottom: 15px;
        }

        .paper-type-btn {
            padding: 8px 16px;
            border: 1px solid var(--medium-gray);
            background-color: var(--white);
            border-radius: var(--border-radius);
            cursor: pointer;
            font-size: 0.9rem;
            transition: all 0.3s ease;
        }

        .paper-type-btn.active {
            background-color: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
        }

        .form-group {
            margin-bottom: 20px;
        }

        .form-row {
            display: flex;
            gap: 20px;
        }

        .form-row .form-group {
            flex: 1;
        }

        label {
            display: block;
            margin-bottom: 8px;
            font-weight: 500;
        }

        input[type="text"],
        input[type="color"],
        select {
            width: 100%;
            padding: 10px 15px;
            border: 1px solid var(--medium-gray);
            border-radius: var(--border-radius);
            font-family: inherit;
            font-size: 1rem;
            transition: border 0.3s ease;
        }

        input[type="text"]:focus,
        select:focus {
            outline: none;
            border-color: var(--primary-color);
        }

        input[type="range"] {
            width: calc(100% - 50px);
            margin-right: 10px;
            vertical-align: middle;
        }

        .checkbox-group {
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .checkbox-group input {
            width: auto;
        }

        .btn-primary {
            background-color: var(--primary-color);
            color: white;
            border: none;
            padding: 12px 25px;
            font-size: 1rem;
            font-weight: 500;
            border-radius: var(--border-radius);
            cursor: pointer;
            transition: background-color 0.3s ease;
            width: 100%;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
        }

        .btn-primary:hover {
            background-color: var(--primary-dark);
        }

        .btn-primary:disabled {
            background-color: var(--dark-gray);
            cursor: not-allowed;
        }

        .status-message {
            margin-top: 15px;
            padding: 10px;
            border-radius: var(--border-radius);
            text-align: center;
            display: none;
        }

        .status-message.success {
            background-color: rgba(40, 167, 69, 0.2);
            color: #28a745;
            display: block;
        }

        .status-message.error {
            background-color: rgba(220, 53, 69, 0.2);
            color: #dc3545;
            display: block;
        }

        .app-footer {
            text-align: center;
            margin-top: 40px;
            padding-top: 20px;
            border-top: 1px solid var(--medium-gray);
            color: var(--dark-gray);
        }

        .app-footer i {
            color: #dc3545;
        }

        /* Responsive design */
        @media (max-width: 1200px) {
            .app-content {
                grid-template-columns: 1fr 1fr;
            }
            
            .preview-section {
                grid-column: span 2;
            }
        }

        @media (max-width: 768px) {
            .app-content {
                grid-template-columns: 1fr;
            }
            
            .preview-section {
                grid-column: span 1;
            }
            
            .form-row {
                flex-direction: column;
                gap: 0;
            }
        }


        .payment-container {
            position: fixed;
            z-index: 99;
            width: 100%;
            height: 100%;
            background-color: rgba(255, 255, 255, 0.85);
            top: 0;
            left: 0;
          
            display: none;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            padding: 20px;
            box-sizing: border-box;
          
            overflow-y: auto;       /* Enables vertical scrolling */
            max-height: 100vh;      /* Prevents container from exceeding viewport */
          }
          
          
          .payment-container h1 {
            font-size: 1.8rem;
            text-align: center;
            margin-bottom: 20px;
            color: #333;
            padding: 0 10px;
          }
          
          #paypal-button-container {
            width: 100%;
            max-width: 350px; /* Fits better on most devices */
            padding: 15px;
            box-sizing: border-box;
          
            display: flex;
            justify-content: center;
          }
          
        
          .close-button {
            position: absolute;
            top: 15px;
            right: 20px;
            font-size: 1.8rem;
            background: none;
            border: none;
            cursor: pointer;
            color: #333;
            font-weight: bold;
            z-index: 100;
            transition: color 0.2s ease;
          }
          
          .close-button:hover {
            color: #e60000;
          }