div class='container'
div class='row'
Span 12
div class='row'
Span 6
Span 6
div class='row'
Span 3
Span 3
Span 3
Span 3
div class='row'
Span 2
Span 2
Span 2
Span 2
Span 2
Span 2
div class='row'
Span 1
Span 1
Span 1
Span 1
Span 1
Span 1
Span 1
Span 1
Span 1
Span 1
Span 1
Span 1