fix for scss build error

[ddtech71]

error detail:

ERROR in ./resources/sass/style.scss
Module build failed (from ./node_modules/css-loader/index.js):
ModuleBuildError: Module build failed (from ./node_modules/postcss-loader/src/index.js):
SyntaxError

(24:6) Missed semicolon

  22 |       vertical-align: middle;
  23 |       border-top: 4px dashed;
> 24 |       border-top: 4px solid\9;
     |      ^
  25 |       border-right: 4px solid transparent;
  26 |       border-left: 4px solid transparent;