Styling HTML tables: frozen rows and columns

Here's a CSS riddle: can we have frozen rows and columns on an HTML <table> element?

Over the years, I've spent a lot of time thinking about this problem, while developing a UI widget framework. The most used widget in UI frameworks is the Grid component (also known as a Data Table, or just Table), and one of its most notorious features is the so-called "frozen" headers. These are headers which always stay in place when you scroll the content. Mind you, this was before position: sticky existed, and usually required some form of JavaScript-based synchronization of rows and headers 😱

So, today I noticed a question on Reddit that asked the same, and decided to give it a try:

As it turns out, position: sticky works wonders!

The gist of the approach is to set sticky positioning on header cells. They require also a background, so that scrolled contents don't show through them:

<div class="wrapper">
  <table>
    <thead>
      <tr>
        <th></th>
        <th>column 1</th>
        <th>column 2</th>
        <!-- ... -->
      </tr>
    </thead>
    <tbody>
      <tr>
        <th>row 1</th>
        <td>scroll</td>
        <td>scroll</td>
        <!-- ... -->
      </tr>
      <!-- ... -->
    </tbody>
  </table>
</div>

.wrapper {
  width: 320px;
  height: 200px;
  overflow: auto;
  position: relative;
}

table {
  table-layout: fixed;
}

thead,
tr>th {
  position: sticky;
  background: #fff;
}

thead {
  top: 0;
  z-index: 2;
}
tr>th {
  left: 0;
  z-index: 1;
}
thead tr>th:first-child {
  z-index: 3;
}

Some gotchas:

Column widths are determined from cell contents. This means that each cell might require an additional element. That is a good idea, since it allows using text-overflow: ellipsis for cell values.
Cell borders require some work to behave consistently, as sticky headers resize during scrolling. See full listing below.

Full source listing

.wrapper {
  border: 1px solid #ccc;
  background: #eee;
  width: 320px;
  height: 200px;
  overflow: auto;
  position: relative;
}
table {
  border-spacing: 0;
  white-space: nowrap;
  table-layout: fixed;
}

thead,
tr>th {
  position: sticky;
  background: #eee;
}

thead {
  top: 0;
  z-index: 2;
}
tr>th {
  left: 0;
  z-index: 1;
}
thead tr>th:first-child {
  z-index: 3;
}

th,
td {
  height: 50px;
  border: 1px solid #ccc;
  border-width: 0 0 1px 1px;
  text-align: left;
  padding: 10px;
  font-family: sans-serif;
}
td {
  background: #fff;
}
th:first-child {
  border-right-width: 1px;
  border-left: 0;
}
th+td,
th:first-child+th {
  border-left: 0;
}
tbody tr:last-child>* {
  border-bottom: 0;
}
tr>*:last-child {
  border-right: 0;
}

<div class="wrapper">
  <table>
    <thead>
      <tr>
        <th></th>
        <th><div style="width: 300px">column 1</div></th>
        <th>column 2</th>
        <th>column 3</th>
        <th>column 4</th>
        <th>column 5</th>
      </tr>
    </thead>
    <tbody>
      <tr>
        <th>row 1</th>
        <td>scroll</td>
        <td>scroll<br>scroll 2 rows</td>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
      </tr>
      <tr>
        <th>row 2</th>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll wide wide wide wide</td>
        <td>scroll</td>
        <td>scroll</td>
      </tr>
      <tr>
        <th>row 3</th>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
      </tr>
      <tr>
        <th>row 4</th>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
      </tr>
      <tr>
        <th>row 5</th>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
      </tr>
      <tr>
        <th>row 6</th>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
        <td>scroll</td>
      </tr>
    </tbody>
  </table>
</div>