On some websites font-weight transition from normal to bold works fine but

I not understand in this demo

Exactly set what want and the timing function is working in my end but that grove font family style is not. Why Not work this?

Is make instant change and no smoothly

Any idea?

Hi @bestdesign

font-weight is quite hard to animate due to a number of reasons best summed up in this post: https://stackoverflow.com/questions/12433645/how-to-animate-text-with-css-font-weight-property-in-jquery-normal-to-bold