body {
            font-family: "Inter", sans-serif;
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            background-color: #f0f2f5;
        }
        .container {
            background-color: white;
            padding: 2.5rem;
            border-radius: 1.5rem;
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
            max-width: 500px;
            width: 100%;
        }
        .file-input-wrapper {
            position: relative;
            overflow: hidden;
            display: inline-block;
            width: 100%;
        }
        .file-input-wrapper input[type=file] {
            font-size: 100px;
            position: absolute;
            left: 0;
            top: 0;
            opacity: 0;
            cursor: pointer;
        }
        .upload-button {
            display: block;
            width: 100%;
            padding: 0.75rem 1.5rem;
            background-color: #4f46e5;
            color: white;
            border: none;
            border-radius: 0.75rem;
            font-weight: 600;
            cursor: pointer;
            transition: background-color 0.2s ease-in-out;
            margin-top: 1.5rem;
        }
        .upload-button:hover {
            background-color: #4338ca;
        }
        .error-message {
            background-color: #fee2e2;
            color: #ef4444;
            padding: 1rem;
            border-radius: 0.75rem;
            margin-top: 1rem;
            display: none; /* Hidden by default */
        }
        .success-message {
            background-color: #d1fae5;
            color: #10b981;
            padding: 1rem;
            border-radius: 0.75rem;
            margin-top: 1rem;
            display: none; /* Hidden by default */
        }
        .loading-spinner {
            border: 4px solid rgba(0, 0, 0, 0.1);
            border-left-color: #4f46e5;
            border-radius: 50%;
            width: 24px;
            height: 24px;
            animation: spin 1s linear infinite;
            display: none; /* Hidden by default */
            margin: 0 auto;
        }
        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }