Edd Yerburgh Software Engineer

Make a responsive tic tac toe board with CSS

In this tutorial you’ll learn how to make a responsive tic tac toe board using a <table> element.

The final board looks like this:

The grid

The grid is created with a <table> element:

<table id="board">
  <tr>
    <td></td>
    <td></td>
    <td></td>
  </tr>
  <tr>
    <td></td>
    <td></td>
    <td></td>
  </tr>
  <tr>
    <td></td>
    <td></td>
    <td></td>
  </tr>
</table>

The next step is style the table so that each <td> element is a square that takes up 1/3 the total table width.

You can do this by setting the <table> element width to 100%, and each <td> element width to 33.3%.

Then create a pseudo element with ::after that has margin-top of 100% to force the parent <td> to have the same height as it has width.

table {
  width: 100%;
}

td {
  width: 33.3%;
}

td:after {
  content: "";
  display: block;
  margin-top: 100%;
}

Because all the widths are set as percentages, the tic tac toe board is responsive.

Adding the borders

You need to set the relevant border colors to transparent using the nth-child pseudo class:

table {
  border-collapse: collapse;
}

td {
  border: 6px solid #222;
}

td:first-of-type {
  border-left-color: transparent;
  border-top-color: transparent;
}

td:nth-of-type(2) {
  border-top-color: transparent;
}

td:nth-of-type(3) {
  border-right-color: transparent;
  border-top-color: transparent;
}

tr:nth-of-type(3) td {
  border-bottom-color: transparent;
}

The final CSS looks like this:

table {
  width: 100%;
  border-collapse: collapse;
}

td {
  width: 33.333%;
  border: 6px solid #222;
}

td::after {
  content: "";
  display: block;
  margin-top: 100%;
}

td {
  border: 6px solid #222;
}

td:first-of-type {
  border-left-color: transparent;
  border-top-color: transparent;
}

td:nth-of-type(2) {
  border-top-color: transparent;
}

td:nth-of-type(3) {
  border-right-color: transparent;
  border-top-color: transparent;
}

tr:nth-of-type(3) td {
  border-bottom-color: transparent;
}

Thanks for reading, any questions leave a comment.