body {
            font-family: ui-sans-serif, system-ui, -apple-system, system-ui, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            background-color: #f9fafb;
            color: #111827;
            max-width: 800px;
            margin: 40px auto;
            padding: 20px;
        }
        .card {
            background: #ffffff;
            padding: 30px;
            border-radius: 12px;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            display: flex;
            flex-wrap: wrap;
            gap: 30px;
            align-items: center;
        }
        h1 {
            font-size: 1.5rem;
            width: 100%;
            margin-top: 0;
            margin-bottom: 1rem;
        }
        .form-section {
            flex: 1;
            min-width: 260px;
        }
        .image-section {
            flex: 1;
            min-width: 260px;
            text-align: center;
        }
        .image-section img {
            max-width: 100%;
            height: auto;
        }
        .input-group {
            margin-bottom: 15px;
        }
        label {
            display: block;
            font-weight: 600;
            font-size: 0.875rem;
            margin-bottom: 5px;
        }
        input[type="number"] {
            width: 100%;
            padding: 0.75rem 1rem;
            font-size: 1rem;
            border: 1px solid #d1d5db;
            border-radius: 8px;
            outline: none;
            box-sizing: border-box;
        }
        input[type="number"]:focus {
            border-color: #53AFE8;
            box-shadow: 0 0 0 3px rgba(83, 175, 232, 0.2);
        }
        #result {
            margin-top: 20px;
            font-size: 1.125rem;
            font-weight: 700;
            color: #1f2937;
        }
        .footer {
            margin-top: 30px;
            font-size: 0.875rem;
            color: #6b7280;
            text-align: center;
            width: 100%;
        }