.views-ui-display-tab-bucket.field .views-fieldsets-fieldset,
.draggable.views-fieldsets-fieldset {
  font-weight: bold;
}
.views-ui-display-tab-bucket.field .views-fieldsets-level-1 {
  padding-left: calc(6px + 1em);
}
.views-ui-display-tab-bucket.field .views-fieldsets-level-2 {
  padding-left: calc(6px + 2em);
}
.views-ui-display-tab-bucket.field .views-fieldsets-level-3 {
  padding-left: calc(6px + 3em);
}
.views-ui-display-tab-bucket.field .views-fieldsets-level-4 {
  padding-left: calc(6px + 4em);
}