Using DW Modern… how to extend the height of the menu area so I can make the logo a little bigger?

To resolve this issue, below is our instruction:
Firstly, follow the jetpack’s guideline in the Blog article on how to use Edit CSS here. http://cmspioneer.com/designwall/blog/using-jetpack-custom-css-for-your-wordpress-site/
Then add the code to the Edit Css.

.navbar .site-title {
     height: 90px
     line-height: 80px;
}

Hope this helps !