$ember-power-select-trigger-border: initial;
$ember-power-select-active-trigger-border: initial;
$ember-power-select-trigger-default-border-radius: 0;

.ember-power-select-typeahead-trigger {
  border: none;
}

.ember-power-select-typeahead-input {
  position: absolute;
  left: 0;
  right: 0;
  width: 100%;
  top: 0;
  bottom: 0;
  border: 1px solid #aaa;
  outline: none;
}
$ember-power-select-trigger-border: initial;
$ember-power-select-active-trigger-border: initial;
$ember-power-select-trigger-default-border-radius: 0;

.ember-power-select-typeahead-trigger {
  border: none;
}

.ember-power-select-typeahead-input {
  position: absolute;
  left: 0;
  right: 0;
  width: 100%;
  top: 0;
  bottom: 0;
  border: $ember-power-select-default-border;
  outline: none;

  & :focus {
    border: $ember-power-select-default-focus-border;
  }
}

Use custom power-select border style
Use custom power-select border style

If the power-select was customized (e.g. by the bootstrap or material theme),
then the power-select-typeahead should also use those styles.

I'm probably missing some styles, but this was really noticable with the bootstrap theme.
