position-absolute导致层级错乱的原因是什么?

<view class=“position-absolute w-100 h-100 bg-white”>

<textarea>textarea</textarea>

<button open-type=“getUserInfo” >授权登陆</button>

</view>

<view class=“w-100 h-100 bg-white”>

主界面

<button>button1</button>

</view>

/**index.wxss**/

.position-absolute {

position: absolute;

}

.position-relative {

position: relative;

}

.w-100 {

width: 100%;

}

.h-100 {

height: 100%;

}

.bg-white {

background-color: white;

}