用户:SegFault

<style>

1. fixed-table-header {

   position: fixed;
   top: 0;
   margin: 0;
   border-collapse: separate;
   border-spacing: 0;
   border-width: 0;
   background-color: transparent;
   pointer-events: none;
   visibility: hidden;

}

1. fixed-table-header > tbody > tr > th {

   border-left-width: 0;
   border-right-width: 0;

}

1. fixed-table-header > tbody > tr > td {

   border-left-width: 0;
   border-right-width: 0;

} </style><script> window.onscroll = function() {

   var tables = document.getElementsByClassName("fix-table-header");
   var clone = document.getElementById('fixed-table-header');
   for (var i = 0; i < tables.length; ++i) {
       var table = tables[i];
       var rect = table.getBoundingClientRect();
       if (rect.top < 0 && rect.bottom > 0) {
           if (clone == null) {
               clone = table.cloneNode(true);
               clone.id = 'fixed-table-header';
               clone.style.width = table.style.width;
               table.parentNode.appendChild(clone);
               var rows = clone.getElementsByTagName('TR');
               for (var i = 0; i < rows.length; i++) {
                   if (rows[i].getElementsByTagName('TD').length == 0) {
                       rows[i].style.visibility = 'visible';
                       rows[i].style.pointerEvents = 'auto';
                   } else break;
               }
           }
           return;  // don't remove clone
       }
   }
   if (clone != null) clone.remove();

} </script>

T11	T12	T13
T22	T21	T23
content	content	content
content	content	content
content	content	content
content	content	content
content	content	content
content	content	content

blahblah

blah

blahblahblah

T11	T12
T22	T21
content	content
content	content
content	content
content	content
content	content
content	content