While I do agree in your comparison the second version looks better. At the same time, and this might be a tad too subjective to have much merit, it feels out of place to me.

Instead, I'd use one of the various approaches where I can create a style = {} object and then apply it to the element, which would just fit better within the rest of my javascript.

(which particular approach to use, .cssText, looping through props, or Object.assign, I'm not sure, but my point is any approach that applies a POJO to the node instead of chaining strikes me as more idiomatic. this is not a hill I'd die on though...)