body {
            font-family: Arial, sans-serif;
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
            background-color: #f4f4f9;
            margin: 0;
        }
        .container {
            text-align: center;
            background-color: white;
            padding: 40px;
            border-radius: 16px;
            box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
            width: 500px;
        }
        h2 {
            color: #333;
        }
        .instructions {
            margin-top: 20px;
            text-align: left;
            color: #555;
        }
        .drop-area {
            border: 2px dashed #28a745;
            border-radius: 16px;
            padding: 40px;
            margin-top: 20px;
            position: relative;
            overflow: hidden;
        }
        .drop-area.active {
            border-color: #218838;
        }
        .drop-area p {
            font-size: 1.2em;
            color: #28a745;
        }
        .drop-area input[type="file"] {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            opacity: 0;
            cursor: pointer;
        }
        .uploaded-files {
            margin-top: 20px;
            text-align: left;
            list-style-type: none;
            padding-left: 0;
        }
        .uploaded-files li {
            background-color: #e0e0df;
            margin-bottom: 5px;
            padding: 10px;
            border-radius: 8px;
        }
        button {
            padding: 15px 30px;
            border: none;
            background-color: #28a745;
            color: white;
            border-radius: 8px;
            cursor: pointer;
            margin-top: 20px;
            font-size: 1em;
        }
        button:hover {
            background-color: #218838;
        }
        .progress-container {
            width: 100%;
            background-color: #e0e0df;
            border-radius: 8px;
            margin-top: 20px;
            height: 20px;
            position: relative;
        }
        .progress-bar {
            width: 0;
            height: 100%;
            background-color: #e0e0df; /* Initial gray color */
            border-radius: 8px;
            transition: width 0.5s ease-in-out;
        }
        .progress-text {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            color: white;
            font-weight: bold;
        }
        a.download-link {
            display: inline-block;
            margin-top: 20px;
            padding: 15px 30px;
            background-color: #28a745;
            color: white;
            text-decoration: none;
            border-radius: 8px;
            font-size: 1em;
        }
        a.download-link:hover {
            background-color: #218838;
        }