.input-group-addon {
    padding: 6px 12px;
    font-size: 14px;
    font-weight: 400;
    line-height: 1;
    color: #555;
    text-align: center;
    background-color: #eee;
    border: 1px solid #ccc;
    border-radius: 4px;
  }
  
  .input-group {
    position: relative;
    display: table;
    border-collapse: separate;
  }
  
  .input-group .form-control, .input-group-addon, .input-group-btn {
    display: table-cell;
  }