[R] Heat maps containing two types of variables

[phii m@iii@g oii phiiipsmith@c@]

I am working with a heat map, as in the REPREX below. The code works 
fine as long as "bigger numbers imply greener and smaller numbers imply 
redder". These are time series where bigger numbers are "better", like 
total employment for example. But I also have cases within the heat map 
where "bigger numbers imply redder and smaller numbers imply greener". 
These are time series where bigger numbers are "worse", like total 
unemployment for example. So suppose column B in dat is of the second 
type, i.e. "bigger numbers imply redder and smaller numbers imply 
greener". I would like the colour coding to be the reverse of what it is 
for columns A and C. How can I modify the code to accomplish this? I 
have tried different approaches with no success. Thanks for your help. 
Philip

# REPREX
library(ggplot2)
library(tidyr)
library(dplyr)
dat <- data.frame(
   date=seq.Date(as.Date("2024-01-01"),as.Date("2024-06-01"),by="month"),
   A=c(1,3,3,4,2,6),
   B=c(3,5,6,4,8,9),
   C=c(10,8,17,19,26,22)
)
dat_long <- pivot_longer(dat,2:4,names_to="variable",values_to="value")
normalize <- function(x) { y <- (x-min(x))/(max(x)-min(x)) }
dat_norm <- mutate(dat,across(2:4,normalize))
dat_long_norm <- 
pivot_longer(dat_norm,2:4,names_to="variable",values_to="norm_value")
dat_long <- inner_join(dat_long,dat_long_norm,by=c("date","variable"))
heatmap <- ggplot(dat_long, aes(x = date, y = variable,fill=norm_value)) 
+
   geom_tile() +
   geom_text(aes(label = as.character(value)),
     color = "black", size = 2.5) +
   labs(title="REPREX",x="",y="")+
   scale_fill_gradient2(low = "#E94A26", mid = "white", high = "#A1D385", 
midpoint = 0.5) +
   scale_x_continuous(breaks=seq.Date(as.Date("2024-01-01"),
     as.Date("2024-06-01"),by="month"),
     labels=function(x) format(x,"%b\n%Y"),position="top")+
   theme(legend.position="none")
heatmap
ggsave("REPREXHeatmap.png",heatmap,height=3.5,width=4.9,dpi=200)