Why TR not taking style?

Question

CSS

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

HTML

<table width="100%" cellspacing="0" cellpadding="0">
   <thead>
      <tr>
         <th scope="col">one</th>
         <th scope="col">two</th>
         <th scope="col">three</th>
      </tr>
   </thead>
   <tbody>
      <tr>
         <th scope="row">Hello</th>
         <td>&nbsp;</td>
         <td>&nbsp;</td>
      </tr>
   </tbody>
</table>

Answer 1

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

Answer 2

Add:

table
{
    border-collapse: collapse;
}

Otherwise tr creates no single block.