Take a look at Susy for layout, bit more flexible than Bootstrap:

https://github.com/oddbird/susy

Also for static site generators take a look at:

https://middlemanapp.com/ (Ruby) http://gohugo.io/ (Go) https://github.com/getpelican/pelican (Python)

When you need to go beyond static sites and take a look at the web frameworks - Ruby on Rails is the obvious one, but I reckon that Meteor (https://www.meteor.com/) could be a good bet now that it has matured. Might save you a lot of time when compared to RoR for certain tasks.