JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tbody>
        <tr>
            <td>1</td>
            <td>2</td>
            <td>3</td>
        </tr>
        <tr>
            <td>4</td>
            <td>5</td>
            <td>6</td>
        </tr>
        <tr>
            <td>7</td>
            <td>8</td>
            <td>9</td>
        </tr>
    </tbody>
</table>

CSS

table, tr, td {
    border: 1px inset black;
    border-collapse: collapse;
    border-spacing: 0;
}

td:hover {
    border: 1px solid red;
}