style.css

.table-drag-select {
  /* Stretch horizontally to fill parent */
  width: 100%;
  /* Keep columns same width */
  table-layout: fixed;
  /* Disable text selection */
  user-select: none;
  /* Center in parent */
  margin-left: auto;
  margin-right: auto;
  /* Remove space between border */
  border-collapse: collapse;
}

/* Table cells */
.table-drag-select td {
  text-align: center;
  /* Cut off long strings of text with ... */
  text-overflow: ellipsis;
  overflow: hidden;
  /* Make transparent gaps between cells. Better than relying on margin
   * because clicking an element's margin doesn't trigger events */
  border: 0.7rem solid transparent;
  background-clip: padding-box;
  /* Make cells reasonable size */
  line-height: 3rem;
  /* Shows more text when text too big to fit into cell */
  padding-left: 0rem;
  padding-right: 0rem;
}

/* Cells that can be interacted with */
.table-drag-select td.cell-enabled {
  background-color: #DDD;
  /* Make the cursor a + symbol */
  cursor: cell;
}

/* Cells that cannot be interacted with */
.table-drag-select td.cell-disabled {
  /* Put yer css here */
}

/* Cells that have been selected */
.table-drag-select td.cell-selected {
  background-color: #A9A9A9;
}

/* Cells that are in the process of being selected */
.table-drag-select td.cell-being-selected {
  /* This is the blue color you see when you select text with the cursor */
  background-color: #3F83D5;
}