input-group.scss

.input-group {
  display: table;

  .form-control {
    position: relative;
    width: 100%;

    &:focus {
      z-index: 2;
    }

    + .btn {
      margin-left: 0;
    }
  }

  // For when you want the input group to behave like inline-block.
  &.inline {
    display: inline-table;
  }

  // within input group, if button exists change focus styles to match input (no offset)
  &:focus-within {
    // stylelint-disable-next-line selector-max-type
    button {
      outline-offset: 0;
    }
  }

  // Autocomplete with embedded icon
  .form-control.autocomplete-embedded-icon-wrap {
    display: inline-flex;
    padding: calc(var(--base-size-4) * 1.25) var(--base-size-8);
  }
}

.input-group .form-control,
.input-group-button {
  display: table-cell;
}

.input-group-button {
  width: 1%;
  vertical-align: middle; // Match the inputs
}

.input-group-button--autocomplete-embedded-icon {
  vertical-align: bottom;
}

.input-group .form-control:first-child,
.input-group-button:first-child .btn {
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
}

.input-group .form-control:first-child,
.input-group-button:first-child .btn:not(.btn-primary) {
  border-color: var(--control-borderColor-rest, var(--color-border-default));
}

.input-group-button:first-child .btn {
  // stylelint-disable-next-line primer/spacing
  margin-right: -1px;
}

.input-group .form-control:last-child,
.input-group-button:last-child .btn {
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
}

.input-group .form-control:last-child,
.input-group-button:last-child .btn:not(.btn-primary) {
  border-color: var(--control-borderColor-rest, var(--color-border-default));
}

.input-group-button:last-child .btn {
  // stylelint-disable-next-line primer/spacing
  margin-left: -1px;
}