Generated by SassMeister.com.

input.scss

$theme-color: #000;
$theme-name: "|customer-a";

*[data-theme="#{$theme-name}"] button {
  color: $theme-color;
}

output.css

*[data-theme="|customer-a"] button {
  color: #000;
}

settings.json

{
  "sass": {
    "compiler": "dart-sass/1.26.10",
    "extensions": {},
    "syntax": "SCSS",
    "outputStyle": "expanded"
  },
  "autoprefixer": false
}