layui表格怎么把表头固定

layui.use('flow', function () {    var flow = layui.flow;    flow.load({        elem: '#LAY_demo1' //流加载容器        , scrollElem: '#LAY_demo1' //滚动条所在元素，一般不用填，此处只是演示需要。        , done: function (page, next) { //执行下一页的回调            var fields = [];            $.each($("input[type='hidden']"), function (i, o) {                fields.push($(o).val());            });            var lis = [];            $.ajax({                type: 'POST',                url: '${ctxPath}/zkEquipment/zkEquipmentReadingMode/' + page,                success: function (res) {                    $.each(res.data, function (index, item) {                        var lisTr = [];                        for (var i = 0; i ' + item[fields[i]] + '');                        }                        var lisTd = lisTr.join('');                        if (index + 1 == res.data.length) {                            lis.push('<tr>' + lisTd + '</tr>');                        } else {                            lis.push('<tr>' + lisTd + '</tr>');                        }                    });                    next(lis.join(''), page <p>css代码：</p><pre class="brush:css;toolbar:false">//控制表格滑动table tbody {    display: block;    overflow-y: scroll;}//固定表头table thead, tbody tr {    display: table;    width: 100%;    table-layout: fixed;}//调节表头宽度table thead {    width: calc(100% - 1em)}