引入全局scss报以下错误：

ERROR Failed to compile with 1 error 下午9:10:10

error in ./src/assets/scss/index.scss

Syntax Error: SassError: Undefined variable: “$color-background”.
on line 6 of src/assets/scss/base.scss
from line 3 of /Users/hui/project/test1/musicapp/src/assets/scss/index.scss

background: $color-background;

--------------^

@ ./src/assets/scss/index.scss 4:14-234 15:3-20:5 16:22-242
@ ./src/main.js
@ multi (webpack)-dev-server/client?http://192.168.1.103:8080&sockPath=/sockjs-node (webpack)/hot/dev-server.js ./src/main.js