.dropdown-table {
  position: relative;
  display: inline-block;
  width: 59ch;
}
.dropdown-selected {
  border: 1px solid #ccc;
  padding: 2px;
  background: #000000;
  cursor: pointer;
}
.dropdown-list {
  display: none;
  position: absolute;
  top: 0;
  left: 0;
  background: #fff;
  border: 1px solid #ccc;
  width: 100%;
  max-height: 200px;
  overflow-y: auto;
  z-index: 10;
}
.dropdown-table.open .dropdown-list {
  display: block;
}
.dropdown-row {
  display: table;
  width: 100%;
  table-layout: fixed;
  font-family: monospace;
  color: red;
}
.dropdown-cell {
  display: table-cell;
  padding: 2px 4px;
  border-bottom: 1px solid #eee;
}

.dropdown-cell.col1 { width: 5ch; } 
.dropdown-cell.col2 { width: 49ch; } 
.dropdown-cell.col3 { width: 5ch; } 

.dropdown-row:hover {
  background: #f0f0f0;
  cursor: default;
}