HTML 固定Table表头

table {
  text-align: left;
  position: relative;
  border-collapse: collapse; 
  }
 
 
   thead th {
     text-align: center;
   }
  th {
   
  position: sticky;
  background-color: #fff;
  top: 0; /* Don't forget this, required for the stickiness */
   
  }