How to get the same highlighting as hugo doc?

I am trying for some days know, but I couldn’t manage to get the same code highlighting as you have at the Hugo documentation website.

My problem seems to be the background of the codeblock:
Myblog: white/grey
Hugo doc: black/dark

I really need the black/dark background for my codeblocks.

Some notes that you might find helpful:

my config.toml

baseurl = "http://yourSiteHere/"                                                
languageCode = "en-us"                                                          
title = "My New Hugo Site"                                                      
pygmentsuseclasses = false                                                      
pygmentsstyle = "github" 

my first.md

+++                                                                             
author = "Panos Georgiadis"                                                     
date = "2015-02-26T11:16:29+01:00"                                              
title = "first"                                                                 
category = "Linux"                                                              
                                                                                
+++  

# Welcome to my blog                                                            
                                                                                
{{< highlight bash >}}                                                          
#!/bin/bash                                                                     
                                                                                
                                                                                
if [ ${#HM[@]} -eq 0 ]                                                          
then                                                                            
       echo "You have to a nice day";                                           
       exit;                                                                    
else                                                                            
        for (( i=0; i < ${#HM[@]}; i++ ))                                       
        do                                                                      
            # In case comment                                                   
            if [ $(echo ${PKG[i]} | grep -c ",") -eq 1 ]; then PKG[ii]=$(echo ${PKG[]} | awk -F ',' '{ print $1 }' | tr -d " \t"); fi
                                                                                
            #echo "${PKG[i]}.batman"                                            
                                                                                
            gedit $SOURCE_DIFF &                                                
        done                                                                    
fi                                                                              
                                                                                
rm /tmp/paok                                                                    
{{< /highlight >}}                                                              
                                                                                
                                                                                
and using the backticks:                                                        
                                                                                
                                                                                
```bash                                                                         
#!/bin/bash                                                                     
                                                                                
                                                                                
if [ ${#HM[@]} -eq 0 ]                                                          
then                                                                            
       echo "You have to a nice day";                                           
       exit;                                                                    
else                                                                            
        for (( i=0; i < ${#HM[@]}; i++ ))                                       
        do                                                                      
            # In case comment                                                   
            if [ $(echo ${PKG[i]} | grep -c ",") -eq 1 ]; then PKG[ii]=$(echo ${PKG[]} | awk -F ',' '{ print $1 }' | tr -d " \t"); fi
                                                                                
            #echo "${PKG[i]}.batman"                                            
                                                                                
            gedit $SOURCE_DIFF &                                                
        done                                                                    
fi                                                                              
                                                                                
rm /tmp/paok                                                                    
```                                                                             

And I noticed that the first section is compiled successfully using the ‘github’ css from pygments. However the second one is not using pygments but something related to the theme which I added (highlight.js) based on your instructions.

So, my only problem is that I cannot get the dark background. Check the screenshot: http://imgur.com/o5dEoNH