docCentor/_book/gitbook/gitbook-plugin-emphasize/plugin.css

.pg-emphasize {
    border-radius: 2px;
    background: #FFFF88;
    padding:1px;
}

.pg-emphasize.pg-emphasize-red {
    background: #ffecec;
}

.pg-emphasize.pg-emphasize-green {
    background: #eaffea;
}