sass版本更新, 旧变量调用语法将不适用新版本

:root {
  // WRONG, will not work in recent Sass versions.
  --accent-color-wrong: $accent-color;

  // RIGHT, will work in all Sass versions.
  --accent-color-right: #{$accent-color};
}

详见: https://sass-lang.com/documentation/breaking-changes/css-vars