How to apply external font to all labels and text box (hint text)/radio buttons by custom css?

[SA_10100358]

how to apply an external font to labels and text box placeholders (hint text), radio buttons -
We tried to apply external font by custom class but did not reflect. could you please help apply external font by custom class for all labels and textbox placeholders (hint text), radio buttons?

[VladimirN]

Are you using Arbortext Editor?

[SA_10100358]

 we are not using Arbortext Editor.