JSFiddle - React, Tailwind, and code Playground

HTML

<table border="1">
            <tr >
                <td class="locked"><div>header 1</div></td>
                <td class="locked"><div>header 2</div></td>
            </tr>
            <tr >
                <td>data 1a</td>
                <td>data 1b</td>
            </tr>
            <tr >
                <td>data 2a</td>
                <td>data 2b</td>
            </tr>
        </table>

CSS

table {
    border-spacing: 0px;
}
.locked {
      position: relative;
      border:none;
}
.locked div{
      border:2px black solid;
      background-color: Yellow;
      margin:-2px;
}