# JavaScript compatibility **Because the Loki Checkout supports both Hyvä Themes and Luma themes, as a module developer, you will need to aim for compatility with both as well. You could actually use Tailwind classes within the Luma-based Loki Checkout as well - the `LokiCheckout_Luma` module uses it too.** However, when it comes to JavaScript, it is often required with Luma to load the JavaScript via RequireJS. To support both themes with different templates, we can use the `hyva_` layout prefix that Hyvä Themes provide. For instance, you could create a PHTML template for Luma with a default handle `loki_checkout.xml` and then rewrite the PHTML template to Hyvä with another layout file `hyva_loki_checkout.xml`. File `hyva_loki_checkout.xml`: ```xml ``` Within Hyvä, you can often load JavaScript in the following way: ```html ``` With Luma, this might need to be wrapped with RequireJS: ```html ```