Pro Service

<?php

    $lastChar = "А";

?>
    
<?php

    foreach ($conndb->query($sql) as $row):
    
?>

<?php if ($lastChar !== ($currentChar = mb_convert_case(mb_substr($row['category_name'], 0, 1), CASE_UPPER))): ?>
<?php $lastChar = $currentChar; ?>
<h1 class="bukva" id="bukva_<?= mb_convert_case($lastChar, CASE_LOWER); ?>"><?= $lastChar; ?></h1>
<?php endif; ?>
                
        <a href="http://localhost/menu_general/masters_page/masters/masters.php">
        

        
            <div class="kategoriya">
                <div class="kolichestvo">0</div>
                <?php echo $row['category_name'] . "\t"; ?>
            </div>
            
        </a>

<?php

    endforeach;
    
?>