Hi There,
Regretfully, there is no way to make the navigation text responsive based on the Bar Height (unless we write a custom JavaScript about it). The logo is an image, its easier to make an image a responsive because you only need to put a height and width 100% to it and it will respond to its container height/width, but that is not the case with font-size, font-size has a vw (viewport width) and vh (viewport height) unit, but that is not really relative to the element’s container but on the viewers screen width. With that said you need to set your font-size that is fit on initial and scroll state.
Thank you for understanding.