css on Rmarkdown: background for selected cells-CodePudding

I use the flextable package to freeze the first row and the first column on an HTML report. David Gohel recently added this option in flextable dev version (0.8.3.13) thanks to CSS comment. However, I want to have the header cells with a white background. I don't know the CSS language. Anyone can help me having only the frozen header cells with a white background?

library(flextable)
dat <- lapply(1:30, function(x) rnorm(n = 50)) %>% 
  setNames(paste0("colname", 1:30)) %>% 
  as.data.frame()

ft_1 <- flextable(dat)
ft_1 <- set_table_properties(ft_1, 
                             opts_html = list(
                               extra_css = ".tabwid tbody tr > :first-child {position: sticky;z-index: 1;left: 0;background: #ddd;}",
                               scroll = list(height="500px")))
ft_1

CodePudding user response：

Just append the .tabwid th {background-color: white; z-index: 2;} in the extra_css argument of set_table_properties.

---
title: "Untitled"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

```{r}
library(flextable)
library(magrittr)

dat <- lapply(1:30, function(x) rnorm(n = 50)) %>% 
  setNames(paste0("colname", 1:30)) %>% 
  as.data.frame()

ft_1 <- flextable(dat)
ft_1 <- set_table_properties(ft_1, 
                             opts_html = list(
                               extra_css = ".tabwid tbody tr > :first-child {position: sticky;z-index: 1;left: 0;background: #ddd;} .tabwid th {background-color: white; z-index: 2;}",
                               scroll = list(height="500px")))
ft_1
```