position.uvue

<template>
  <!-- #ifdef APP -->
  <scroll-view style="flex: 1">
    <!-- #endif -->
    <view style="flex-grow: 1">
      <view>
        <text>position: relative</text>
        <scroll-view
          style="width: 250px; height: 250px; background-color: gray"
        >
          <view
            style="width: 50px; height: 50px; background-color: red"
          ></view>
          <view class="common" style="position: relative">
            <text class="text">relative</text>
          </view>
          <view
            style="width: 50px; height: 50px; background-color: blue"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: red"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: green"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: blue"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: red"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: green"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: blue"
          ></view>
        </scroll-view>
      </view>

      <view>
        <text>position: absolute</text>
        <scroll-view
          style="width: 250px; height: 250px; background-color: gray"
        >
          <view
            style="width: 50px; height: 50px; background-color: red"
          ></view>
          <view class="common" style="position: absolute">
            <text class="text">absolute</text>
          </view>
          <view
            style="width: 50px; height: 50px; background-color: blue"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: red"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: green"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: blue"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: red"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: green"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: blue"
          ></view>
        </scroll-view>
      </view>

      <view>
        <text>position: fixed</text>
        <scroll-view
          style="width: 250px; height: 250px; background-color: gray"
        >
          <view
            style="width: 50px; height: 50px; background-color: red"
          ></view>
          <view class="common fixed" style="position: fixed">
            <text class="text">fixed</text>
          </view>
          <view
            style="width: 50px; height: 50px; background-color: blue"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: red"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: green"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: blue"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: red"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: green"
          ></view>
          <view
            style="width: 50px; height: 50px; background-color: blue"
          ></view>
        </scroll-view>
      </view>
    </view>
    <!-- #ifdef APP -->
  </scroll-view>
  <!-- #endif -->

</template>

<style>
.common {
  width: 50px;
  height: 50px;
  background-color: green;
  top: 25px;
  left: 25px;
  justify-content: center;
  align-items: center;
}

.fixed {
  /* #ifdef WEB*/
  top:  calc(var(--window-top) + 25px);
  /* #endif */
}

.text {
  white-space: nowrap;
  width: 100%;
}
</style>