Ion-item bottom line style

Hi, im trying to change the style of an ion list items with css, with the following code i can change the top, right and left , but i cant change the bottom one , can someone helpme with this:

    <button ion-item   *ngFor="let item of food; let i = index"   (click)="viewFood(item)" >
      <p>{{item.nombre}} </p><button disabled  item-right color="light" ion-button round> <div class="precio">${{item.precio}}</div></button>


ion-list .item .item-inner{

border-bottom-style: dotted;

  width: 100%;
  height: 50px;
  padding-top: 5px;
  padding-bottom: 5px;
  margin: 10px;

  box-sizing: border-box;
  border: 2px solid rgb(161, 150, 150);
  border-radius: 4px;
  background-color: #f8f8f8;
  font-size: 16px;
  resize: none;
  border-style: dotted;