CSS for adding a rudimentary console to jsfiddle

console.css

footer, 
footer *, 
footer *:before, 
footer *:after {
  box-sizing: border-box;
}

.console {
  background: black;
  width: 100%;
  position: absolute;
  bottom: 0;
  min-height: 100%;
  font-family: monospace;
  overflow-y: scroll;
}

.console-log {
  color: white;
}

.console-error {
  color: red;
}

#console-toggle {
  width: 100%;
  background: #ddd;
  position: absolute;
  height: 0;
  bottom: 0;
  transition: height .1s linear;
}

#console-toggle::before {
  content: ' ';
  width: 100%;
  position: absolute;
  top: -5px;
  height: 5px;
  padding: 5px;
  background: #ddd;
}

#console-toggle::after {
  content: 'console';
  font-weight: bold;
  color: red;
  padding: 5px 10px;
  text-align: center;
  font-family: monospace;
  border-radius: 5px 5px 0 0;
  width: auto;
  height: 15px;
  position: absolute;
  right: 15px;
  top: -25px;
  background: #ddd;
  cursor: pointer;
}

#console-toggle.open {
  height: 75%;
}