<style>
table {
  border-collapse: collapse;
  width: 100%; /* width 100% */
  border: 1px solid #000; /* border size 1 */
  margin-left: 0; 
  margin-right: auto; /* alignment left */
}

/* Header (first row) */
table thead tr {
  background-color: #000000 !important;
  color: #ffffff !important;
  font-weight: bold;
}

/* Alternating body rows */
table tbody tr:nth-child(odd) {
  background-color: #f2f2f2;
}

table tbody tr:nth-child(even) {
  background-color: #ffffff;
}

/* Cell styling */
table td, table th {
  padding: 8px;
  border: 1px solid #000; /* border size 1 */
}
</style>

<table align="left" border="1" cellpadding="0" cellspacing="0" style="width: 100%;">
  <thead>
    <tr>
      <th>Header 1</th>
      <th>Header 2</th>
      <th>Header 3</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Row 1 Column 1</td>
      <td>Row 1 Column 2</td>
      <td>Row 1 Column 3</td>
    </tr>
    <tr>
      <td>Row 2 Column 1</td>
      <td>Row 2 Column 2</td>
      <td>Row 2 Column 3</td>
    </tr>
  </tbody>
</table>
