JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <thead>
    <tr>
        <th>blah</th>
        <th>fwee</th>
        <th>spoon</th>
    </tr>
    </thead>
    <tr>
        <td>blah</td>
        <td>fwee</td>
        <td>spoon</td>
    </tr>
    <tr>
        <td>blah</td>
        <td>fwee</td>
        <td>spoon</td>
    </tr>
</table>

CSS

table {
    border-collapse:separate;
    border:solid black 1px;
    border-radius:6px;
    -moz-border-radius:6px;
}

td, th {
    border-left:solid black 1px;
    border-top:solid black 1px;
}

th {
    background-color: blue;
    border-top: none;
}

td:first-child {
     border-left: none;
}