refactor: update styles to css variables

Author: dcoa

src/index.scss

@@ -1,7 +1,4 @@
-@import "~@edx/brand/paragon/fonts";
-@import "~@edx/brand/paragon/variables";
-@import "~@openedx/paragon/scss/core/core";
-@import "~@edx/brand/paragon/overrides";
+@use "@openedx/paragon/styles/css/core/custom-media-breakpoints" as paragonCustomMediaBreakpoints;
 
 @import "~@edx/frontend-component-header/dist/index";
 @import "~@edx/frontend-component-footer/dist/footer";