IPython/html/static/notebook/less/notificationarea.less

#notification_area {
    .pull-right();
    z-index: 10;
}

.indicator_area {
    color: @navbar-default-link-color;
    margin-left: 5px;
    margin-right: 5px;
    width: 11px;
    z-index: 10;
    text-align: center;
}

#kernel_indicator {
    .pull-right();
    .indicator_area();
}

#modal_indicator {
    .pull-right();
    .indicator_area();
}

.edit_mode_icon:before {
    .icon(@fa-var-pencil)
}

.command_mode_icon:before {
    .icon(' ');
}

.kernel_idle_icon:before {
    .icon(@fa-var-circle-o);
}

.kernel_busy_icon:before {
    .icon(@fa-var-circle);
}

.kernel_dead_icon:before {
    .icon(@fa-var-bomb);
}

.kernel_disconnected_icon:before {
    .icon(@fa-var-chain-broken);
}