title: RMarkdown: how to rotate table column headers
body: <p>I'm trying to rotate table column headers in RMarkdown. Since I don't have an understanding of CSS my attempts so far have proven to be futile. </p>
  
  <p>So, how can I rotate the table column headers?</p>
  
  <p>Here is a minimal example for a table in RMarkdown:</p>
  
  <pre><code>---
  title: "Untitled"
  output: 
    html_document:
      df_print: paged
      style: ./Table.css
  ---
  
  ```{r setup, include=FALSE}
  knitr::opts_chunk$set(echo = TRUE)
  library(kableExtra)
  library(knitr)
  ```
  
  &lt;div class="table-header-rotated"&gt;
  
  ```{r test, result="asis"}
  
  kable(head(mtcars), "html")
  ```
  &lt;/div&gt;
  </code></pre>
  
  <p>And the CSS file was made from the code presented here: <a href="https://codepen.io/chriscoyier/pen/Fapif" rel="noreferrer">https://codepen.io/chriscoyier/pen/Fapif</a></p>
  
  <p>Can anyone give me a hint?</p>