Extracting checkout theme css as separate link

BTCPayServer/Views/Invoice/Checkout.cshtml

@@ -24,6 +24,8 @@
     <bundle name="wwwroot/bundles/checkout-bundle.min.js" />
     <script>vex.defaultOptions.className = 'vex-theme-btcpay'</script>
 
+    <link href="/checkout/css/themes/default.css" rel="stylesheet" />
+
     @if (!string.IsNullOrEmpty(Model.CustomCSSLink))
     {
         <link href="@Model.CustomCSSLink" rel="stylesheet" />

BTCPayServer/bundleconfig.json

@@ -37,7 +37,7 @@
         "inputFiles": [
             "wwwroot/vendor/font-awesome/css/font-awesome.css",
             "wwwroot/vendor/vex/css/vex.css",
-            "wwwroot/checkout/**/*.css",
+            "wwwroot/checkout/*/*.css",
             "wwwroot/vendor/jquery-prettydropdowns/prettydropdowns.css"
         ]
     },