th.sort-header::-moz-selection { background: transparent; }

th.sort-header::selection { background: transparent; }

th.sort-header {
  cursor: pointer;
}

th.sort-header::-moz-selection,
th.sort-header::selection {
  background: transparent;
}

table th.sort-header::after {
  content: '';
  float: right;
  margin-top: 7px;
  border-width: 0 4px 4px;
  border-style: solid;
  border-color: #404040 transparent;
  visibility: hidden;
}

table th.sort-header:hover::after {
  visibility: visible;
}

table th.sort-up::after,
table th.sort-down::after,
table th.sort-down:hover::after {
  visibility: visible;
  opacity: 0.4;
}

table th.sort-up::after {
  border-bottom: none;
  border-width: 4px 4px 0;
}

th[role=columnheader]:not(.no-sort) {
	cursor: pointer;
}

th[role=columnheader]:not(.no-sort):after {
	content: '';
	float: right;
	margin-top: 7px;
	border-width: 0 4px 4px;
	border-style: solid;
	border-color: #404040 transparent;
	visibility: hidden;
	opacity: 0;
	-webkit-user-select: none;
	-moz-user-select: none;
	user-select: none;
}

th[aria-sort=ascending]:not(.no-sort):after {
	border-bottom: none;
	border-width: 4px 4px 0;
}

th[aria-sort]:not(.no-sort):after {
	visibility: visible;
	opacity: 0.4;
}

th[role=columnheader]:not(.no-sort):hover:after {
	visibility: visible;
	opacity: 1;
}

Use CSS from tables from 5.0.0
Use CSS from tables from 5.0.0