Fira+ operator on Atom

styles.less

atom-text-editor,
atom-workspace {
	text-rendering: optimizeLegibility;
	-webkit-font-smoothing: antialiased;
	font-family: "Operator Mono";
	font-weight: 500;
	line-height: 1.7;
}

atom-panel.tool-panel {
	font-size: 0.88em;
}

atom-text-editor::shadow {
	.entity.other.attribute-name {
		font-style: italic;
	}

	.entity.name.function {
		font-style: italic;
	}

	.entity.other.attribute-name {
		font-style: italic;
	}


	.keyword.operator:not(.accessor),
	.punctuation.definition.entity.css,
	.storage.type.function.arrow {
		font-family: 'Fira Code';
	}

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