frc-ui/lib/not-found/style/index.css

React Web UI

.swc-not-found {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  overflow: hidden;
  font-size: 36px;
  opacity: 0.2;
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
}