atomstyle.less

atom-text-editor {
  -webkit-font-smoothing: antialiased;
}

atom-text-editor::shadow{
  .storage.type.function.arrow, .operator {
    font-family: 'FiraCode-Retina';
    text-rendering: optimizeLegibility;
    vertical-align: baseline;
  }

  .string.quoted, .string.regexp {
    -webkit-font-feature-settings: "liga" off, "calt" off;
  }

}