悬停文本在PHP中没有正确显示？

i want to display a text formatted in a div that shows up when hovering over a text. I managed this this way in my PHP-file:

echo "<style> " . ".'runes" . $i . ":hover'" . "{" . 
     "position: absolute;
      background-color: rgba(0, 0, 0, 0.9);
      width: 225px;
      height: 300px;
      margin-left: -20px;
      margin-top: -267px;
      text-align: center;
      border: 1px solid #fff;
      -webkit-border-radius: 5px;
      -moz-border-radius: 5px;
      border-radius: 25px;}" . "</style>";
echo "<div class='runes" . $i . ":hover'" . "><div class='runestext'>TEXT</div></div>";

And in my CSS-file:

.runestext {
    font-family: Verdana;
    font-style: normal;
    font-weight: bold;
    font-size: 16px;
    color: #fff;
    text-decoration: none;
}

My problem is, that the div with class=runes shows up properly, but the text i want to display in this div formatted with class=runestext shows up unformatted in the middle of the page. Where is the mistake? Thanks.

PS: Do not worry about the $i, that is because i loop the whole code 10 times for getting 10div's.