/* minimal inline style to keep theme consistent */
        body {
            margin: 0 auto;
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
            background: #f1f5f9;
            color: #0f172a;
            max-width: 1200px;
        }
        .container {
            display: flex;
            min-height: 100vh;
        }
        .left-column {
            width: 260px;
            background: #0f172a;
            color: #e2e8f0;
            padding: 2rem 1rem;n 
            position: sticky;
            top: 0;
            height: 100%;
            overflow-y: auto;
            box-sizing: border-box;
            flex-shrink: 0;
        }
        .site-name a {
            color: #facc15;
            font-size: 1.8rem;
            font-weight: 700;
            text-decoration: none;
            letter-spacing: -0.5px;
        }
        .site-name {
            margin-bottom: 2.5rem;
            border-bottom: 1px solid #334155;
            padding-bottom: 1rem;
        }
        .menu-icon {
            display: none;
            font-size: 2rem;
            color: #facc15;
            cursor: pointer;
        }
        .menu a {
            display: block;
            color: #cbd5e1;
            text-decoration: none;
            padding: 0.6rem 0.8rem;
            border-radius: 8px;
            transition: all 0.15s;
            font-size: 0.95rem;
            margin-bottom: 0.2rem;
        }
        .menu a:hover {
            background: #1e293b;
            color: white;
        }
        .right-column {
            flex: 1;
            padding: 2rem 2.5rem;
            max-width: 1200px;
            box-sizing: border-box;
        }
        .content h1 {
            font-size: 2.2rem;
            margin-bottom: 0.25rem;
            color: #0f172a;
        }
        .content p {
            color: #334155;
            line-height: 1.6;
        }
        .converter-card {
            background: white;
            border-radius: 20px;
            padding: 2rem 2rem 2.5rem;
            box-shadow: 0 10px 25px -5px rgba(0,0,0,0.05);
            border: 1px solid #e2e8f0;
            margin: 2rem 0;
        }
        .drop-zone {
            border: 2px dashed #94a3b8;
            border-radius: 16px;
            padding: 3rem 1.5rem;
            text-align: center;
            cursor: pointer;
            transition: all 0.2s;
            background: #f8fafc;
        }
        .drop-zone:hover {
            border-color: #2563eb;
            background: #eff6ff;
        }
        .drop-zone.dragover {
            border-color: #2563eb;
            background: #dbeafe;
        }
        .drop-zone .icon {
            font-size: 3.5rem;
            margin-bottom: 0.5rem;
        }
        .format-grid {
            display: flex;
            flex-wrap: wrap;
            gap: 0.6rem;
            justify-content: center;
            margin: 1.8rem 0 1rem;
        }
        .format-btn {
            background: #f1f5f9;
            border: 1px solid #e2e8f0;
            padding: 0.5rem 1.4rem;
            border-radius: 40px;
            font-weight: 600;
            font-size: 0.9rem;
            cursor: pointer;
            transition: all 0.15s;
            color: #1e293b;
        }
        .format-btn:hover {
            background: #e2e8f0;
        }
        .format-btn.active {
            background: #2563eb;
            color: white;
            border-color: #2563eb;
        }
        .result-panel {
            display: none;
            margin-top: 2rem;
            border-top: 1px solid #e2e8f0;
            padding-top: 1.8rem;
        }
        .result-panel.show {
            display: block;
        }
        .preview-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 2rem;
            margin: 1.5rem 0;
        }
        .preview-box {
            background: #f8fafc;
            padding: 1.2rem;
            border-radius: 12px;
            border: 1px solid #e2e8f0;
        }
        .preview-box h4 {
            margin: 0 0 0.6rem 0;
            color: #1e293b;
        }
        .preview-box img {
            max-width: 100%;
            height: auto;
            max-height: 220px;
            border-radius: 8px;
            background: white;
            box-shadow: 0 2px 6px rgba(0,0,0,0.04);
        }
        .file-size {
            color: #64748b;
            font-size: 0.9rem;
            margin-top: 0.4rem;
        }
        .download-btn {
            display: inline-block;
            background: #10b981;
            color: white;
            border: none;
            padding: 0.75rem 2rem;
            border-radius: 40px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            text-decoration: none;
            text-align: center;
            width: 100%;
            transition: background 0.15s;
            border: 1px solid #059669;
        }
        .download-btn:hover {
            background: #059669;
        }
        .feature-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
            gap: 1.5rem;
            margin: 2.5rem 0;
        }
        .feature-card {
            background: #f8fafc;
            padding: 1.5rem;
            border-radius: 16px;
            border: 1px solid #e2e8f0;
        }
        .feature-card .emoji {
            font-size: 2rem;
            margin-bottom: 0.3rem;
        }
        footer {
            margin-top: 3.5rem;
            padding-top: 1.5rem;
            border-top: 1px solid #e2e8f0;
            font-size: 0.9rem;
            color: #475569;
        }
        .footer-menu a {
            color: #2563eb;
            text-decoration: none;
            margin: 0 0.3rem;
        }
        .footer-menu a:hover {
            text-decoration: underline;
        }
        @media (max-width: 760px) {
            .container {
                flex-direction: column;
            }
            .left-column {
                width: 100%;
                height: auto;
                position: relative;
                padding: 1rem;
            }
            .menu-icon {
                display: block;
                position: absolute;
                top: 1.2rem;
                right: 1.5rem;
            }
            .menu {
                display: none;
                flex-direction: column;
                margin-top: 1rem;
            }
            .menu.active {
                display: flex;
            }
            .right-column {
                padding: 1.5rem;
            }
            .preview-grid {
                grid-template-columns: 1fr;
                gap: 1rem;
            }
        }
  /* Tablet */
@media (min-width: 769px) and (max-width: 1024px) {
    .left-column {
        width: 220px;
    }
    
    .right-column {
        padding: 1.5rem;
    }
}