nextjs-style-guide/.vitepress/theme/custom.css

.VPNavBarTitle.has-sidebar .title {
  border-top: none !important;
  padding-top: 0;
}

.VPNavBarTitle .title {
  white-space: normal;
  line-height: 1.2;
  padding: 6px 0;
}

.VPNavBarTitle .title span {
  display: block;
  min-width: 0;
  max-width: 100%;
  overflow-wrap: anywhere;
}