tu-view-plus/lib/src/button/style/button-group.css

.tu-button-group {
  display: inline-flex;
  vertical-align: middle;
  padding: 4px;
  box-shadow: inset 1px 1px 2px var(--tu-color-shadow-dark, #babbc0), inset -1px -1px 2px var(--tu-color-shadow-light, #ffffff), 1px 1px 3px var(--tu-color-shadow-dark, #babbc0), -1px -1px 2px var(--tu-color-shadow-light, #ffffff);
  border-radius: var(--tu-border-radius-feedback, 4px);
  box-sizing: border-box;
  padding: 3px;
}
.tu-button-group::before,
.tu-button-group::after {
  display: table;
  content: "";
}

.tu-button-group::after {
  clear: both;
}

.tu-button-group + .tu-button-group {
  margin-left: 12px;
}
.tu-button-group > .tu-button {
  float: left;
  position: relative;
}
.tu-button-group > .tu-button + .tu-button {
  margin-left: 3px;
}
.tu-button-group > .tu-button--mini {
  padding: 4px 7px;
}

.tu-button-group > .tu-button.tu-button--primary, .tu-button-group > .tu-button.tu-button--success, .tu-button-group > .tu-button.tu-button--info, .tu-button-group > .tu-button.tu-button--danger, .tu-button-group > .tu-button.tu-button--warning {
  padding: 2px 5px;
}
.tu-button-group > .tu-button--small {
  padding: 5px 11px;
}

.tu-button-group > .tu-button.tu-button--primary, .tu-button-group > .tu-button.tu-button--success, .tu-button-group > .tu-button.tu-button--info, .tu-button-group > .tu-button.tu-button--danger, .tu-button-group > .tu-button.tu-button--warning {
  padding: 3px 9px;
}
.tu-button-group > .tu-button--medium {
  padding: 6px 17px;
}

.tu-button-group > .tu-button.tu-button--primary, .tu-button-group > .tu-button.tu-button--success, .tu-button-group > .tu-button.tu-button--info, .tu-button-group > .tu-button.tu-button--danger, .tu-button-group > .tu-button.tu-button--warning {
  padding: 4px 15px;
}
.tu-button-group > .tu-button--large {
  padding: 8px 21px;
}

.tu-button-group > .tu-button.tu-button--primary, .tu-button-group > .tu-button.tu-button--success, .tu-button-group > .tu-button.tu-button--info, .tu-button-group > .tu-button.tu-button--danger, .tu-button-group > .tu-button.tu-button--warning {
  padding: 6px 19px;
}