Change font-family of the entire app

[tomasz86]

Please try this version:

:not([role="img"]):not([class^="fa-"]):not([class*=" fa-"]):not([class^="icon-"]):not([class*=" icon-"]) {
	font-family: 'Oxygen Mono' !important;
}

:not([role="img"]):not([class^="fa-"]):not([class*=" fa-"]):not([class^="icon-"]):not([class*=" icon-"]) .cm-editor * {
	font-family: 'Arial' !important;
}