I didn't catch this when I reported the text issue on the dark style for the Sign Up Now button, but the Sign Up Now button is still using XenForo's default styling on both styles.
This was fixed on the light style, but it seems it didn't get fixed on the dark style, as the background color is still the default XenForo styling (from inspecting the element and then comparing it to XenForo Community), the button's size seems bigger than on the light style, and the text in general looks different than on the light style. For comparison, here is the button on the light style, fully fixed: And here it is on the dark style, not appearing fixed:
