使用mutate_all和cross时如何在case_when中添加列名

我有下面的dataframe，我想改变ENV dataframe中的所有列，用case_when函数替换一些值:

  metrics <-
    structure(list(var = c("SST", "SSS"), min = c(-1.82623172259469, 
    0.0106425614590989), max = c(30.7357019713913, 62.4178951570953
    ), Q1 = c(29.6467844102333, 37.2283509056568), Q2 = c(25.0978897764037, 
    35.1366150711973), Q3 = c(1.08054073780591, 33.6817701728394), 
        Q4 = c(-1.75609879755353, 22.3324745864139), slope.L = c(-0.219833625638, 
        -0.478071840394898), slope.R = c(0.352529811255446, 0.0881111953059067
        )), row.names = c(NA, -2L), class = c("tbl_df", "tbl", "data.frame"
    ))
    ENV1<-
    structure(list(SST = c(-1.18181673490857, -1.29487169195505, 
    -1.2891296530063, -1.16459061806231, -1.02749131873705, -0.877831755030538, 
    -0.827006290249864, -0.87501492439503, -0.907842479642887, -0.925488955993432, 
    -0.928734689365441), SSS = c(34.4828464105725, 34.4536828344067, 
    34.4394813115398, 34.4402418419719, 34.4202143674095, 34.3793988878528, 
    34.3479811742902, 34.3259612267216, 34.2944239596526, 34.2533693730831, 
    34.225624174873)), row.names = 30:40, class = "data.frame")

ENV1 |> mutate_all(funs(
  case_when(
    . < metrics[metrics$var == x,]$Q1 ~ 0,
    . <= metrics[metrics$var == x,]$Q3 ~ 1,
    . > metrics[metrics$var == x,]$Q4 ~ 0
  )
))

我的问题是，应该放什么而不是x？我试着使用names(.)，一个列的名称(因此它从metrics数据帧中获取一个值.但它不起作用.我还试着使用colnames(.)，vars(.)，像人物()-没有运气