hikashop css is loaded after user.css is loaded

-- HikaShop version -- : 6.1.1
-- Joomla version -- : 5.3.4
-- PHP version -- : 8.4.x
-- Browser(s) name and version -- : any
-- Error-message(debug-mod must be tuned on) -- : none

When I change, in the user.css, the colors of the buttons, they are overwritten by the Hikashop css files.
How can I force the user.css to be loaded after the Hikashop css files?

Thanks in advance.