How do I edit bootstrap theme in rmarkdown?

Question

I am currently using the cosmo theme in rmarkdown. If I want to change the color of my navigation menu, or, more specifically, the menu highlight, which file should I edit?

Answer 1

If you really want to change the cosmos CSS you can find it here: [path to libraries]/rmarkdown/rmd/h/bootstrap-3.3.5/css/cosmo.min.css However if I only need to change one thing, I usually just put the CSS into the markdown document as in the following example.

You can also attach your own CSS as documented here: http://rmarkdown.rstudio.com/html_document_format.html#custom_css

---
title: "Untitled"
author: "Ian Wesley"
date: "May 25, 2017"
output: 
  html_document:
    theme: cosmo

---

<style>
  h2{
    font-size: 50px !important;
    color: crimson !important
  }
</style>

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

## R Markdown

This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see <http://rmarkdown.rstudio.com>.

When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:

```{r cars}
summary(cars)
```

## Including Plots

You can also embed plots, for example:

```{r pressure, echo=FALSE}
plot(pressure)
```