JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div>1</div>
  <div>2</div>
  <div>3</div>
  <div>4</div>
  <div>5</div>
  <div>6</div>
</div>

CSS

.container div {
    width: 150px;
    display: inline-block;
}
.container div.new-row {
    color: red;
}

JavaScript

var topOffset;
$(document).ready(function(){
    $('.container div').each(function(index){
        if (index === 0) {
          // first item, set offset
          topOffset = $(this).offset().top;
          $(this).addClass('new-row');
        } else if (topOffset < $(this).offset().top){
          // new item, new row
          
          $(this).addClass('new-row');
          topOffset = $(this).offset().top;
        }
    });
});