grid.css

/* 
 * Flex table with scrollable tbody:
 * https://jsfiddle.net/bakgx0yz/1/
 */

table.grid-table {
  display: flex;
  flex-flow: column nowrap;
  border-spacing: 0;
  height: 100%;
  width: 100%;
}

table.grid-table thead th .grid-col-filter {
  width: 100%;
  box-sizing: border-box;
  border: 1px solid rgb(212, 212, 212);
  padding: 0 2px;
  font-weight: normal !important;
}

table.grid-table thead {
  display: block;
  flex: 0 0 auto;
  overflow-y: scroll;
  overflow-x: hidden;
}

/* we always enable vertical scrollbar to perfeclty align headers with body
   but we dont actually want to see it - dont know of an analog for other
   browsers */
table.grid-table thead::-webkit-scrollbar {
  visibility: hidden;
}

table.grid-table tbody {
  display: block;
  flex: 1 1 auto;
  overflow: scroll;
  /* tbody is focusable using tabindex, so make sure to disable outline */
  outline: none;
}

table.grid-table tr {
  width: 100%;
}

table.grid-table thead tr,
table.grid-table tbody tr {
  display: table;
  table-layout: fixed;
}

table.grid-table tbody td {
  height: 30px;
}

/*
 * borders
 */
table.grid-table th,
table.grid-table td {
  border-right: 1px solid rgb(212, 212, 212);
  padding: .4rem;
  box-sizing: border-box;
  text-overflow: ellipsis;
  white-space: nowrap;
  overflow: hidden;
}

table.grid-table th:first-child,
table.grid-table td:first-child {
  border-left: 1px solid rgb(212, 212, 212);
}

table.grid-table th {
  border-top: 1px solid rgb(212, 212, 212);
  border-bottom: 1px solid rgb(212, 212, 212);
  height: 4rem;
  background: -webkit-gradient(linear, 0% 100%, 0% 0%, from(rgb(238, 238, 238)), to(rgb(255, 255, 255))) padding-box;
  text-align: left;
  vertical-align: top;
}

/*
 * zebra
 */
table.grid-table tbody tr:nth-child(odd) {
  background-color: rgb(243, 243, 243);
}

table.grid-table tbody tr:nth-child(even) {
  background-color: rgb(253, 253, 253);
}

/*
 * virtual scroll
 */
table.grid-table tbody x-rowgroup {
  display: block;
}

/*
 * filters
 */
table.grid-table .grid-col-filter-clear-btn {
  position: absolute;
  right: 0;
  padding-left: 0.5rem;
  padding-right: 0.3rem;
  line-height: 1.5em;
  cursor: pointer;
  color: #888;
}

table.grid-table .grid-col-filter-clear-btn:before {
  content: "\2a09";
}

/*
 * sorting
 */
table.grid-table .grid-col-sort-icon {
  margin-left: 0.5em;
}

table.grid-table .grid-col-sort-icon-asc:before {
  content: "\25be";
}

table.grid-table .grid-col-sort-icon-desc:before {
  content: "\25b4";
}

table.grid-table .grid-col-title {
  cursor: default;

  -webkit-touch-callout: none;
  -webkit-user-select: none;
  -khtml-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

table.grid-table .grid-col-title-sort {
  cursor: pointer;
}

/*
 * row selection
 */
table.grid-table tbody tr.grid-row-selected td {
  background-color: rgb(201, 221, 225);
}

/*
 * menu
 */
.grid-menu-toggle {
  position: absolute;
  top: 0;
  right: 0;
  padding: 0.5rem;
  border: 1px solid rgb(212, 212, 212);
  background-color: #eee;
  font-weight: bold;
  z-index: 10;

  -webkit-touch-callout: none;
  -webkit-user-select: none;
  -khtml-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

.grid-menu-toggle:before {
  content: " \2630";
}

.grid-menu {
  position: absolute;
  top: 2em;
  right: 1em;
  display: none;
  border: 1px solid rgb(212, 212, 212);
  background-color: #eee;
}

.grid-menu-open {
  display: block !important;
  z-index: 100;
  box-shadow: 3px 3px 3px #888;
}

.grid-menu .grid-menu-list {
  padding: 0;
  margin: 0;
}

.grid-menu .grid-menu-list li {
  list-style-type: none;
  border-bottom: 1px solid rgb(212, 212, 212);
  padding: 0.5em 1em;
  cursor: pointer;
}

.grid-menu .grid-menu-list li:hover {
  background-color: #ddd;
}

.grid-menu .grid-menu-col-visible:before {
  content: "\2611\00a0"; /* ticked checkbox */
}

.grid-menu .grid-menu-col-hidden:before {
  content: "\2610\00a0"; /* empty checkbox */
}