JSFiddle - React, Tailwind, and code Playground

HTML

<div class="dashboard-body">
  <p>You don't have any sales data.</p>
  <p>Please add a new book or upload CSVs.</p>

  <div class="btn-group">
    <a href="#">
      <input class="add-new-book-btn" type="submit" value="Add New Book">
    </a>
    <a href="#">
      <input class="add-new-book-btn" type="submit" value="Upload CSV">
    </a>
  </div>

CSS

.dashboard-body {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    flex-direction: column;
  }
  .btn-group{
    display: flex;
    align-self:stretch;
    justify-content: space-between;
  }