如何使用ggplot2在这个负条和正条中以不同的方式添加轴文本？

install.packages("ggplot2")
library(ggplot2)

data <- data.frame(
  category = c("A", "B", "C", "D"),
  value = c(-10, 20, -15, 30)
)

plot <- ggplot(data, aes(x = category, y = value)) +
  coord_flip() +
  scale_y_continuous(limits = c(min(data$value), max(data$value)))

plot <- plot +
  geom_bar(data = subset(data, value < 0), aes(fill = "Negative"), stat = "identity") +
  geom_bar(data = subset(data, value >= 0), aes(fill = "Positive"), stat = "identity")

plot <- plot +
  theme(axis.text.x = element_text(color = c("red", "blue", "green", "orange"),
                                   face = c("bold", "italic", "bold.italic", "plain")))