cover-view部分屏幕样式出问题

- 当前 Bug 的表现（可附上截图）

iphone5的屏幕左侧漏了一点

- 预期表现

iphone6的屏正常

- 提供一个最简复现 Demo

.bswitch {

position:absolute;

left:235rpx;

top:2vh;

width: 280rpx;

height:60rpx;

overflow:hidden;

margin:0 auto;

text-align:center;

font-family:"Microsoft Yahei";

border-radius:30rpx;

border: 2rpx solid #03d1ab;

}

.bswitch .item {

display:inline-block;

width: 140rpx;

height:60rpx;

line-height:60rpx;

text-align:center;

overflow:hidden;

font-size:28rpx;

color:#03d1ab;

background:#fff;

}

.bswitch .itemcur {

color:#fff;

background:#03d1ab;

}

<cover-view class="bswitch">

<cover-view class="item itemcur" bindtap='topmap'>地图</cover-view>

<cover-view class="item" bindtap='toplist'>列表</cover-view>

</cover-view>

样式为宽280rpx的<cover-view>，套两个宽140rpx的<cover-view>