The issue arise for ui-widget (outputlabel) since the font in not set ui-widget level and hence it resolve to the ?ln=poseidon-layout.

body {
font-family: "Open Sans","Helvetica Neue",sans-serif;
font-size: 14px;
color: #5f666c;
-webkit-font-smoothing: antialiased;
padding: 0;
margin: 0;
height: 100%;
}