List's bottom border disappear

Hi all
the bottom border of list in my Ionic 2 project doesn’t show, I’m not sure if this cause from transpile, since I update to RC3 and get error copy message.

image

html code:

<ion-header>
  <ion-navbar>
    <ion-title>
      GoTW
    </ion-title>
  </ion-navbar>
</ion-header>

<ion-content>
  <ion-list>
    <button ion-item (click)="navToTRA()">
      <ion-icon name="md-train" item-left></ion-icon>TRA
    </button>
    <button ion-item (click)="navToBus()">
      <ion-icon name="md-bus" item-left></ion-icon>Bus
    </button>
    <button ion-item (click)="navToAbout()">
      <ion-icon name="md-clipboard" item-left></ion-icon>About
    </button>
  </ion-list>
</ion-content>

and the error message

my ionic info

Cordova CLI: 6.4.0
Ionic Framework Version: 2.0.0-rc.3
Ionic CLI Version: 2.1.14
Ionic App Lib Version: 2.1.7
Ionic App Scripts Version: 0.0.46
ios-deploy version: Not installed
ios-sim version: Not installed
OS: Windows 10
Node Version: v6.6.0
Xcode version: Not installed

ion-list:not(:last-child){
border-bottom: 1px solid #E8E8E8;
}
i think the above css are effecting you have to add the same css for last child . by default is above thats why your not able to see the bottom border