<div id="wrap">

  <!-- section -->
  <div class="section">
    <div class="center">

      <div id="grid">
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
      </div>

    </div>
  </div>
  <!--/section -->

</div>

html,
body {
  margin: 0;
  padding: 0;
  font-family: sans-serif;
  font-size: 16px;
  line-height: 1.4;
  color: #555;
  background: #fff;
}

* {
  box-sizing: border-box;
}

#wrap {
  position: relative;
}

.section {
  padding: 40px;
}

.center {
  width: 100%;
  max-width: 980px;
  margin: auto;
}

#grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  grid-gap: 5px;
  position: relative;
}

.item {
  height: 200px;
  box-shadow: inset 0 0 0 1px #aaa;
  padding: 20px;
  
  &:hover {
    box-shadow: inset 0 0 0 1px #f00;
  }
}

$(window).on('load resize', function () {
  var $grid = $('#grid');
  
  $grid.find('.item').each(function () {
    var $item = $(this),
      gridPositionX = $grid.offset().left,
      gridPositionY = $grid.offset().top,
      itemPositionX = ($item.offset().left - gridPositionX).toFixed(0, 0),
      itemPositionY = ($item.offset().top - gridPositionY).toFixed(0, 0);

    $item.text('X: ' + itemPositionX + ', Y: ' + itemPositionY);    
  })
});