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