如何 Package 带有上标的ggplot()图例标题？在下面的例子中，我想在“温度”一词之后 Package 图例标题
示例数据（尝试\n）

library(tidyverse)
library(ggtext)
library(ggplot2)

ggplot(mtcars, aes(x = disp, y = hp, fill = hp, size = mpg)) +
  geom_point(shape = 21) +
  scale_fill_gradient2(low = "blue", high = "red",
                       midpoint = mean(mtcars$hp),
                       name = 'Air Temperature \nTrend (<sup>o</sup>C yr<sup>-1</sup>)') +
  scale_size_continuous(name = 'Air Temperature \nTrend (<sup>o</sup>C yr<sup>-1</sup>)') +
  theme(legend.title = element_markdown())

在这个例子中，有一个类似的SO问题（link here）对我不起作用。

nameFill <- bquote(atop(Air~Temperature~phantom(),
                         Trend~(degree*C~yr^-1)))

ggplot(mtcars, aes(x = disp, y = hp, fill = hp, size = mpg)) +
  geom_point(shape = 21) +
  scale_fill_gradient2(low = "blue", high = "red",
                       midpoint = mean(mtcars$hp),
                       name = nameFill) +
  scale_size_continuous(name = nameFill) +
  theme(legend.title = element_markdown())