PhaserEditor2D-v3/source/editor/plugins/phasereditor2d.scene/styles/EventPropertyDialog.css

.EventPropertyDialogHelpPane {
    height: 10rem;
    overflow-y: scroll;
    align-items: start !important;
}

.dark .EventPropertyDialogHelpPane {
    border-top-style: solid;
    border-top-width: 1px;
    border-radius: 0px;
}