Absolutely. MageAnts can update your Magento 1 store to the latest 1.x version while keeping your theme intact and responsive:
- We start with a full file and database backup.
- Audit all installed modules and make sure that they're compatible with the target Magento 1.x release.
- Upgrade core Magento, then update theme files to eliminate deprecated methods and layout breaks.
- Perform full testing: checkout, admin panel, product pages, mobile responsiveness.
- Make sure customer, order, and product data remain untouched and intact.