perf: modular sass architecture (#2052)

- Modularized the Sass architecture to enhance code maintainability and reduce the output file size
- Replaced deprecated `@import` with `@use` / `@forward`

.stylelintrc.json

@@ -1,4 +1,5 @@
 {
+  "ignoreFiles": ["_sass/vendors/**"],
   "extends": "stylelint-config-standard-scss",
   "rules": {
     "no-descending-specificity": null,