.zen-view-splitter-header {
  background: transparent !important;  
  border-radius: 0 0 34px 34px !important;
  padding-top: 0 !important;
  padding-bottom: 0.8rem !important;
  justify-content: center !important;
  align-items: center !important;
}

.zen-view-splitter-header > toolbarbutton {
  color: red !important;
  position: relative;
}

.zen-tab-rearrange-button::before {
  content:"";
  width: 30px; height: 30px;
  top: 0px; right: 0px;
  position: absolute;
}

.zen-tab-rearrange-button:hover::after {
  content:"";
  width: 28px;
   height: 28px;
  right: -4px; top: 0px;
  position: absolute;
   border-radius: 0 0 0 28px !important;
   box-shadow: 0 0 25px 15px rgba(0,0,0,0.5) !important;
}

.zen-tab-unsplit-button::before {
  content:"";
  width: 30px; height: 30px;
  left: 0px; top: 0px;
  position: absolute;
}

.zen-tab-unsplit-button:hover::after {
  content:"";
  width: 28px; height: 28px;
  left: -4px; top: 0px;
  position: absolute;
   border-radius: 0 0 24px 0 !important;
   box-shadow: 0 0 25px 15px rgba(0,0,0,0.5) !important;
}