$("#sortable").sortable({
  // sortable 配置
});

#sortable {
  display: flex; /* 替代 float */
  flex-wrap: wrap;
  /* 或者使用 grid */
  /* display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); */
}

$("#sortable").sortable({
  tolerance: "pointer",
  helper: "clone",
  opacity: 0.8
});

#sortable {
  overflow: hidden; /* 清除浮动 */
}

#sortable div {
  float: left;
  margin: 5px;
  width: 100px;
  height: 100px;
  position: relative; /* 添加相对定位 */
}

$("#sortable").sortable({
  placeholder: "sortable-placeholder",
  helper: function(e, item) {
    var helper = item.clone();
    helper.css({
      "width": item.width(),
      "float": "none", // 移除浮动
      "position": "absolute"
    });
    return helper;
  }
});

.sortable-placeholder {
  background: #f0f0f0;
  border: 1px dashed #ccc;
  visibility: visible !important;
  float: none !important;
  position: relative !important;
}