static get styles() {
    return css`
      :host {
        display: flex;
      }

      .combobox__selection {
        flex: none;
      }

      .combobox__input {
        display: block;
      }

      .selection-chip {
        border-radius: 4px;
        background-color: #eee;
        padding: 4px;
        font-size: 10px;
      }

      .selection-chip--highlighted {
        background-color: #ccc;
      }

      * > ::slotted([slot='_textbox']) {
        outline: none;
        width: 100%;
        height: 100%;
        box-sizing: border-box;
        border: none;
        border-bottom: 1px solid;
      }
    `;
  }
Can be used to visually indicate the next