Button CSS classes:
btn (every button gets this)
btn-default btn-info btn-danger (various colors set)
btn-block (block instead of inline)

Shading classes:
well

Text css:
text-primary
text-center

rows:


container has class row
row as 12 cols
col-xs-3 - means column, extra small, 3 columns

Extras:
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Full Cheat Sheet:
https://hackerthemes.com/bootstrap-cheatsheet/