<!-- 视口 -->
<section class="viewport">
  <header class="header flex-col">
    <!-- 位置信息 -->
    <div class="location flex-col">
      <span class="label">我的位置</span>
      <span class="value">上海市</span>
    </div>
    <!-- 总结 -->
    <div class="summary">12° | 有风</div>
    <!-- 当前温度 -->
    <div class="temperature">12</div>
    <!-- 最低温和最高温 -->
    <div class="temperature-range">
      <div>
        <span class="label">最高</span>
        <span class="value">15°</span>
      </div>
      <div>
        <span class="label">最低</span>
        <span class="value">7°</span>
      </div>
    </div>
    <!-- 天气状况 -->
    <div class="condition">有风</div>
  </header>
  <section class="grid">
    <div class="placeholder"></div>
    <article style="aspect-ratio: 5/2">
      <h2>每小时天气预报</h2>
    </article>
    <article style="aspect-ratio: 1">
      <h2>10日天气预报</h2>
    </article>
    <article style="aspect-ratio: 1">
      <h2>空气质量地图</h2>
    </article>
    <article class="tile">
      <h2>紫外线指数</h2>
    </article>
    <article class="tile">
      <h2>日落</h2>
    </article>
    <article style="aspect-ratio: 5/2">
      <h2>风</h2>
    </article>
    <article class="tile">
      <h2>体感温度</h2>
    </article>
    <article class="tile">
      <h2>降水</h2>
    </article>
    <article class="tile">
      <h2>能见度</h2>
    </article>
    <article class="tile">
      <h2>湿度</h2>
    </article>
    <article style="aspect-ratio: 5/2">
      <h2>上弦月</h2>
    </article>
    <article class="tile">
      <h2>平均</h2>
    </article>
    <article class="tile">
      <h2>气压</h2>
    </article>
    <footer>
      <h2>中国上海市的天气</h2>
      <p>进一步了解<a href="">天气数据</a>和<a href="">地图数据</a></p>
    </footer>
  </section>
</section>

html {
  height: 100%;
}
body {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: system-ui;
}
* {
  box-sizing: border-box;
}
a {
  color: inherit;
}

.flex-col {
  display: flex;
  flex-direction: column;
}

.viewport {
  width: 390px;
  height: 80vh;
  padding: 0 16px;
  border: 3px solid black;
  overflow: hidden auto;
  border-radius: 16px;
}

.header {
  position: sticky;
  z-index: 2;
  top: 16px;
  margin: 48px 0;
  text-align: center;
}

.header::before {
  content: "";
  position: absolute;
  z-index: -1;
  top: -16px;
  left: 0;
  right: 0;
  height: 96px;
  background: linear-gradient(to bottom, white 50%, transparent);
}

.location > .label {
  font-size: 28px;
}
.location > .value {
  font-size: 12px;
  margin-top: 8px;
}

.summary {
  position: absolute;
  left: 0;
  right: 0;
  top: 56px;
  opacity: 0;
}

.temperature {
  margin-top: 8px;
  position: relative;
  font-size: 80px;
  font-weight: 300;
}
/* 单独处理温度符号，确保数字是居中的 */
.temperature::after {
  content: "°";
  position: absolute;
  top: 0;
}

.temperature-range {
  margin-top: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
}

.temperature-range > div {
  display: flex;
}
.temperature-range .label {
  margin-right: 4px;
  writing-mode: vertical-lr;
}
.temperature-range .value {
  font-size: 32px;
  font-weight: 300;
}

.condition {
  margin-top: 8px;
}

@supports (animation-timeline: scroll()) {
  .summary {
    animation: linear fade-in both;
    animation-timeline: scroll();
    animation-range: 144px 160px;
  }
  .temperature {
    animation: linear fade-out both;
    animation-timeline: scroll();
    animation-range: 96px 144px;
  }

  .temperature-range {
    animation: linear fade-out both;
    animation-timeline: scroll();
    animation-range: 64px 96px;
  }
  .condition {
    animation: linear fade-out both;
    animation-timeline: scroll();
    animation-range: 32px 64px;
  }
}

@keyframes fade-out {
  to {
    opacity: 0;
  }
}

@keyframes fade-in {
  to {
    opacity: 1;
  }
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: -112px;
}

.grid > .placeholder {
  position: sticky;
  z-index: 1;
  top: 0;
  grid-column: span 2;
  height: 112px;
  background-color: white;
}

.grid > article {
  position: relative;
  background-color: hsl(0, 0%, 92%);
  border-radius: 16px;
}
.grid > article > h2 {
  position: sticky;
  top: 96px;
  z-index: 1;
  padding: 8px 16px;
  background-color: inherit;
  border-radius: inherit;
}

.grid > article:not(.tile) {
  grid-column: span 2;
}

.grid > .tile {
  aspect-ratio: 1;
}

.grid > footer {
  grid-column: span 2;
  text-align: center;
  margin-bottom: 48px;
}
.grid > footer > h2 {
  font-weight: 600;
}
.grid > footer > p {
  margin-top: 8px;
  font-size: 12px;
}