How is the caret on Twitter Bootstrap constructed?

Question

This is more of a curiosity question than something I really need to know.

On this page:

http://twitter.github.com/bootstrap/components.html#buttonDropdowns

Answer 1

Here is the CSS for an upward facing caret, based on the CSS from bootstrap:

.caret-up {
  display: inline-block;
  width: 0px;
  height: 0px;
  margin-left: 2px;
  vertical-align: middle;
  border-top: none;
  border-bottom: 4px solid #FFFFFF;
  border-right: 4px solid transparent;
  border-left: 4px solid transparent;
  border-top-width: 0px;
  border-top-style: dotted;
  content: "";
}