Set class to variable?

Question

PHP

Tell me how to correctly set the class of the $nyu variable, the fact is that at the beginning there is already a class + do I need to set another class for this variable?
So that the number is in a circle

echo '<a class="menu" style="color:#FF7F00" href="'.$base_path.'mess/vhod_user.php"><b>Новые сообщения'.$nyu.'</b></a><br>';

Answer 1

$myClass = "my-custom-class";
echo '<a class="menu '.$myClass.'" style="color:#FF7F00" href="'.$base_path.'mess/vhod_user.php"><b>Новые сообщения'.$nyu.'</b></a><br>';

Answer 2

$nyu = '('.$cifra.')';
so what?