TD.tab-button {
  border-left: 2px solid #A0A0A0;
  border-top: 2px solid #A0A0A0;
  border-right: 2px solid #404040;
  border-bottom: 2px solid #A0A0A0;
  padding: 0.1em 1em;
  background: #B0B0B0;
  color: black;
  cursor: default;
  white-space: nowrap;
}

TD.tab-button-active {
  border-left: 2px solid #A0A0A0;
  border-top: 2px solid #A0A0A0;
  border-right: 2px solid #404040;
  border-bottom: 2px transparent; /* invisible border */
  padding: 0.1em 1em;
  color: black;
  cursor: default;
  white-space: nowrap;
}

TD.tab-button-endspace {
  border-bottom: 2px solid #A0A0A0;
  width: 100%;
  cursor: default;
}

TD.tab-button-space {
  border-bottom: 2px solid #A0A0A0;
  cursor: default;
}

TD.tab-page {
  border-left: 2px solid #A0A0A0;
  border-right: 2px solid #404040;
  border-bottom: 2px solid #404040;
  padding: 0;
  color: black;
  vertical-align: top;
  text-align: left;
}

TD.tab-page-content {
  text-align: left;
  color: black;
  padding: 10px; /* note: em styling does NOT work */
}