JSFiddle - React, Tailwind, and code Playground

HTML

<table class="siteList">
  <thead class="siteList__header">
    <tr>
      <th>見出し</th>
      <th>見出し</th>
      <th>見出し</th>
    </tr>
  </thead>
</table>

CSS

.siteList__header {
  background-image: linear-gradient(to right, #babdc7, #6d7996);
}

th {
  width: 200px;
}