title: Differences in R Markdown syntax highlighting for in-line code
body: <p>The following minimal R Markdown file <code>minimal.Rmd</code> produces different <code>minimal.html</code> output (via "Knit HTML" in RStudio) depending on my system. The first is the result on my Windows 8 machine. The second is the result on my Windows 7 (64-bit) machine. Differences:</p>
  
  <ul>
  <li>Red syntax highlighting on in-line code in Win8 version</li>
  <li>Bold header text in Win8 version</li>
  </ul>
  
  <p>Differences persist even if I use different highlight styles like "tango" or even "null". </p>
  
  <p><strong>Q:</strong> What's going on? Shouldn't the output .html files be identical? Is RStudio not finding some important coloring package on one of my systems?</p>
  
  <p><strong><code>minimal.Rmd</code></strong></p>
  
  <pre><code>---
  title: "Minimal"
  author: "Foo"
  date: "Tuesday, May 19, 2015"
  output: 
    html_document:
      highlight: default
  ---
  
  Some hypertext: see &lt;http://rmarkdown.rstudio.com&gt;.
  
  Inline code: `echo = FALSE`
  
  Block code: 
  ```{r}
  summary(cars)
  x &lt;- 3
  y &lt;- 5
  x + y
  mean(c(x,y))
  ```
  </code></pre>
  
  <p><strong><code>minimal.html</code> (Windows 8)</strong></p>
  
  <p><img src="https://i.stack.imgur.com/HLQnk.png" alt="minimal8"></p>
  
  <p><strong><code>minimal.html</code> (Windows 7)</strong></p>
  
  <p><img src="https://i.stack.imgur.com/s7jGQ.png" alt="enter image description here"></p>