Why TR not taking style?

Answer 1

Add:

table
{
    border-collapse: collapse;
}

Otherwise tr creates no single block.

Simple example:

table
{
  border: 5px solid #900;
  background: #fff;
}
tr
{
  border: 5px solid #090;
}
td
{
  background: #ccc;
  padding: 5px 0;
}

table + table
{
  border-collapse: collapse;
}

<table>
  <tr>
    <td>def</td>
    <td>ault</td>
  </tr>
</table>
<table>
  <tr>
    <td>coll</td>
    <td>apse</td>
  </tr>
</table>

Answer 2

tr by definition wont take border styles. You need to apply it to the td's within it:

table tr td {border-bottom:1px solid #008999}

Answer 3

Try giving

table tr th {border-bottom:1px solid #008999}

Then you can use

table { border-collapse: collapse; }
table tr {border-bottom:1px solid #008999; }

See The collapsing border model