在R中更改条形图(网格包)上的标题大小

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

data <- data.frame(
  category = c("A", "B", "C", "D"),
  value = c(10, 20, 15, 25)
)

bar_plot <- ggplot(data, aes(x = category, y = value)) +
  geom_bar(stat = "identity") +
  labs(title = "Bar Plot", x = "Category", y = "Value") +
  theme(plot.title = element_text(size = 20))

print(bar_plot)