Hello, world!
span test
span1
span1
span1
span1
span4
span4
span4
span8
span8
span8
span offset test
span4
span4
span3 offset1
span3 offset1
span3 offset2
span3 offset2
span3 offset3
span3 offset3
Nesting columns
Level1 1 column
Level 2
Level 2
button
btn
btn btn-primary
btn btn-info
btn btn-success
btn btn-warning
btn danger