Question

http://examine.com/v5x/creatine.html#summary – hover over Summary.

What’s the CSS that controls it? I can’t seem to find it.

Answer 1

Active: active class (true for most Bootstrap features)

Hover:

.navbar .nav > li > a:focus,
.navbar .nav > li > a:hover {
  color: #333333;
  text-decoration: none;
  background-color: transparent;
}

Source

EDIT

Line 3804 of your CSS:

.nav-list > .active > a,
.nav-list > .active > a:hover {
  color: #ffffff;
  text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.2);
  background-color: #0088cc;
}

background-color here is causing your blue background. Simply change it to the desired value, and change color to color: #00A5B5;.