基于 Senni的回复，我在一个单独的CSS文件:

Based on Senni's reply, I added following to a separate CSS-file:

div.ui-tooltip {
    max-width: 400px;
}

一个旁注:请确保您单独的CSS在ui-css之后 之后，否则将无效.否则，您也可以使用!important-标记.

A sidenote: Make sure your separate CSS follows after the ui-css, otherwise there will be no effect. Otherwise you also could use the !important - marker.