/* table for calendar customization */
#cal th {
  text-align: center;
}

#cal td {

}

#cal .cal_cell {
  height: 5em;
  width: 100px;
  vertical-align: top;
  text-align: left;
  border: 1px solid grey;
}

#cal table tr {
  border: 1px solid grey;
}

#cal .week_cell {
  border-bottom: 1px solid black;
}

The styling information for the calendar

CI calendar class CSS for the table

css, codeigniter

CSS