<div class="grid">
  <div class="item">
    <div class="item-content">1</div>
  </div>
  <div class="item">
    <div class="item-content">2</div>
  </div>
  <div class="item">
    <div class="item-content">3</div>
  </div>
  <div class="item">
    <div class="item-content">4</div>
  </div>
  <div class="item">
    <div class="item-content">5</div>
  </div>
  <div class="item">
    <div class="item-content">6</div>
  </div>
  <div class="item">
    <div class="item-content">7</div>
  </div>
  <div class="item">
    <div class="item-content">8</div>
  </div>
  <div class="item">
    <div class="item-content">9</div>
  </div>
  <div class="item">
    <div class="item-content">10</div>
  </div>
  <div class="item">
    <div class="item-content">11</div>
  </div>
  <div class="item">
    <div class="item-content">12</div>
  </div>
  <div class="item">
    <div class="item-content">13</div>
  </div>
  <div class="item">
    <div class="item-content">14</div>
  </div>
  <div class="item">
    <div class="item-content">15</div>
  </div>
  <div class="item">
    <div class="item-content">16</div>
  </div>
  <div class="item">
    <div class="item-content">17</div>
  </div>
  <div class="item">
    <div class="item-content">18</div>
  </div>
  <div class="item">
    <div class="item-content">19</div>
  </div>
  <div class="item">
    <div class="item-content">20</div>
  </div>
</div>

.grid {
  position: relative;
}
.item {
  position: absolute;
  width: 200px;
  height: 200px;
  line-height: 200px;
  margin: 5px;
  z-index: 1;
}
.item.muuri-item-hidden {
  z-index: 0;
}
.item.muuri-item-positioning {
  z-index: 2;
}
.item.muuri-item-releasing {
  z-index: 3;
}
.item.muuri-item-dragging {
  z-index: 4;
}
.item-content {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: center;
  background: red;
  font-size: 50px;
  color: white;
  cursor: pointer;
}
.item.muuri-item-dragging .item-content {
  background: blue;
}
.item.muuri-item-releasing .item-content {
  background: blueViolet;
}

var dragSortOptions = {
  action: 'swap',
  threshold: 50
};
var grid = new Muuri('.grid', {
  dragEnabled: true,
  dragStartPredicate: function (item, event) {
    // Prevent first item from being dragged. 
    if (grid.getItems().indexOf(item) === 0) {
      return false;
    }
    // For other items use the default drag start predicate.
    return Muuri.ItemDrag.defaultStartPredicate(item, event);
  },
  dragSortPredicate: function (item) {
    var result = Muuri.ItemDrag.defaultSortPredicate(item, dragSortOptions);
    return result && result.index === 0 ? false : result;
  }
});