ggplot2: geom_bar()；如何改变填充顺序，使条形不会在具有较高值的条形中丢失？

# 导入ggplot2包
library(ggplot2)

# 创建一个示例数据集
data <- data.frame(
  category = c("A", "B", "C", "D"),
  value = c(10, 20, 30, 40)
)

# 将category列转换为factor，并指定顺序
data$category <- factor(data$category, levels = c("D", "C", "B", "A"))

# 绘制条形图
ggplot(data, aes(x = category, y = value, fill = category)) +
  geom_bar(stat = "identity")