parallax

视差

让前后景以克制的速度差移动，建立轻量层次感。

预览

滚动时背景与前景以不同速度移动，从而营造纵深感。

滚动

视差

继续

实现「视差」：让前后景以克制的速度差移动，建立轻量层次感。参数设为位移 48px、速度差 35%、轴向 y。由视口进入或滚动进度驱动。使用语义化 HTML，CSS 作用域限定在 .motion-demo--parallax。为 prefers-reduced-motion 和 .force-reduced-motion 提供等价的低动态方案。

markup.html

<div class="motion-demo motion-demo--parallax" data-motion="parallax" aria-label="视差 示例">
  <div class="motion-scroll-track"><span>滚动</span><article class="motion-surface">
    <strong>视差</strong>
    <span class="motion-line"></span>
    <span class="motion-line"></span>
  </article><span>继续</span></div>
</div>

motion.css

.motion-demo.motion-demo--parallax {
  box-sizing: border-box;
  position: relative;
  display: grid;
  place-items: center;
  width: min(100%, 34rem);
  min-height: 15rem;
  padding: 2rem;
  overflow: hidden;
  color: #18181b;
  background: #fafafa;
  border: 1px solid #e4e4e7;
  border-radius: 16px;
  isolation: isolate;
}

.motion-demo.motion-demo--parallax *, .motion-demo.motion-demo--parallax *::before, .motion-demo.motion-demo--parallax *::after {
  box-sizing: border-box;
}

.motion-demo.motion-demo--parallax .motion-surface {
  position: relative;
  display: grid;
  gap: 0.65rem;
  width: min(100%, 18rem);
  padding: 1.25rem;
  background: #ffffff;
  border: 1px solid #e4e4e7;
  border-radius: 16px;
  box-shadow: none;
}

.motion-demo.motion-demo--parallax .motion-surface strong { font-weight: 500; }

.motion-demo.motion-demo--parallax .motion-line {
  display: block;
  width: 100%;
  height: 0.5rem;
  background: #e4e4e7;
  border-radius: 999px;
}

.motion-demo.motion-demo--parallax .motion-line:last-child { width: 62%; }

.motion-demo.motion-demo--parallax .motion-button {
  position: relative;
  min-height: 2.75rem;
  padding: 0.75rem 1.1rem;
  color: white;
  font: inherit;
  font-weight: 700;
  background: #18181b;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
}

.motion-demo.motion-demo--parallax .motion-button:focus-visible { outline: 3px solid rgb(37 99 235 / 32%); outline-offset: 3px; }

.motion-demo.motion-demo--parallax .motion-action-row {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 0.85rem;
}

.motion-demo.motion-demo--parallax .motion-replay-scene {
  width: min(100%, 22rem);
  display: grid;
  place-items: center;
}

.motion-demo.motion-demo--parallax .motion-pausable-scene {
  width: min(100%, 22rem);
  display: grid;
  place-items: center;
}

.motion-demo.motion-demo--parallax button.motion-surface {
  color: inherit;
  font: inherit;
  text-align: start;
  cursor: pointer;
}

.motion-demo.motion-demo--parallax .motion-replay-button,
.motion-demo.motion-demo--parallax .motion-undo-button,
.motion-demo.motion-demo--parallax .motion-dismiss-button,
.motion-demo.motion-demo--parallax .motion-pause-button {
  min-height: 2.75rem;
  padding: 0.65rem 0.9rem;
  color: #18181b;
  font: 650 0.78rem/1 ui-sans-serif, system-ui, sans-serif;
  background: #ffffff;
  border: 1px solid #d4d4d8;
  border-radius: 8px;
  cursor: pointer;
}

.motion-demo.motion-demo--parallax .motion-replay-button:focus-visible,
.motion-demo.motion-demo--parallax .motion-undo-button:focus-visible,
.motion-demo.motion-demo--parallax .motion-dismiss-button:focus-visible,
.motion-demo.motion-demo--parallax .motion-pause-button:focus-visible,
.motion-demo.motion-demo--parallax [data-reorder-item]:focus-visible,
.motion-demo.motion-demo--parallax [data-swipe-target]:focus-visible {
  outline: 3px solid rgb(37 99 235 / 32%);
  outline-offset: 3px;
}

.motion-demo.motion-demo--parallax .motion-status {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.motion-demo.motion-demo--parallax .motion-ripple-ink {
  position: absolute;
  width: 12px;
  height: 12px;
  pointer-events: none;
  background: rgb(255 255 255 / 72%);
  border-radius: 50%;
  transform: translate(-50%, -50%) scale(0.95);
  opacity: 0;
}

.motion-demo.motion-demo--parallax .motion-state-stack { position: relative; width: min(100%, 18rem); height: 9rem; }
.motion-demo.motion-demo--parallax .motion-state { position: absolute; inset: 0; display: grid; place-items: center; padding: 1rem; background: #ffffff; border: 1px solid #e4e4e7; border-radius: 16px; }
.motion-demo.motion-demo--parallax .motion-state--to { background: #18181b; color: white; }

.motion-demo.motion-demo--parallax .motion-scroll-track > span { color: #71717a; font: 600 0.72rem/1.2 ui-monospace, monospace; letter-spacing: 0.08em; text-transform: uppercase; }
.motion-demo.motion-demo--parallax .motion-orbit-item { display: grid; place-items: center; width: 2.5rem; height: 2.5rem; color: white; background: #2563eb; border-radius: 50%; }
.motion-demo.motion-demo--parallax .motion-text-stack { position: relative; width: min(100%, 18rem); min-height: 4rem; }
.motion-demo.motion-demo--parallax svg { width: min(100%, 20rem); height: auto; }

.motion-demo.motion-demo--parallax { max-height: 15rem; overflow-x: hidden; overflow-y: auto; place-items: start center; }
.motion-demo.motion-demo--parallax .motion-scroll-track { display: grid; place-items: center; gap: 10rem; width: 100%; min-height: 48rem; padding-block: 5rem; }
.motion-demo.motion-demo--parallax .motion-surface { animation: motion-parallax linear both; animation-timeline: scroll(nearest); animation-range: 10% 80%; }
@keyframes motion-parallax { from { transform: translateY(17px); } to { transform: none; } }
@supports not (animation-timeline: scroll()) { .motion-demo.motion-demo--parallax .motion-surface { animation: motion-parallax 700ms linear both; } }

@keyframes motion-parallax-reduced-fade {
  from { opacity: 0.84; }
  to { opacity: 1; }
}

.force-reduced-motion .motion-demo.motion-demo--parallax {
  animation: motion-parallax-reduced-fade 160ms cubic-bezier(0.23, 1, 0.32, 1) both !important;
}

.force-reduced-motion .motion-demo.motion-demo--parallax *,
.force-reduced-motion .motion-demo.motion-demo--parallax *::before,
.force-reduced-motion .motion-demo.motion-demo--parallax *::after {
  animation: none !important;
  animation-delay: 0ms !important;
  animation-iteration-count: 1 !important;
  transition-property: opacity, color, background-color, border-color !important;
  transition-duration: 160ms !important;
  transition-delay: 0ms !important;
  scroll-behavior: auto !important;
}

.force-reduced-motion .motion-demo.motion-demo--parallax .motion-button,
.force-reduced-motion .motion-demo.motion-demo--parallax [data-reorder-item],
.force-reduced-motion .motion-demo.motion-demo--parallax [data-swipe-target],
.force-reduced-motion .motion-demo.motion-demo--parallax [data-spring-target] {
  transform: none !important;
}

.force-reduced-motion .motion-demo.motion-demo--parallax .motion-path { stroke-dashoffset: 0 !important; }
.force-reduced-motion .motion-demo.motion-demo--parallax .motion-word--from { opacity: 0 !important; visibility: hidden; }
.force-reduced-motion .motion-demo.motion-demo--parallax .motion-word:not(.motion-word--from) { opacity: 1 !important; filter: none !important; transform: none !important; }

@media (prefers-reduced-motion: reduce) {
  .motion-demo.motion-demo--parallax {
    animation: motion-parallax-reduced-fade 160ms cubic-bezier(0.23, 1, 0.32, 1) both !important;
  }

  .motion-demo.motion-demo--parallax *, .motion-demo.motion-demo--parallax *::before, .motion-demo.motion-demo--parallax *::after {
    animation: none !important;
    animation-delay: 0ms !important;
    animation-iteration-count: 1 !important;
    transition-property: opacity, color, background-color, border-color !important;
    transition-duration: 160ms !important;
    transition-delay: 0ms !important;
    scroll-behavior: auto !important;
  }

  .motion-demo.motion-demo--parallax .motion-button,
  .motion-demo.motion-demo--parallax [data-reorder-item],
  .motion-demo.motion-demo--parallax [data-swipe-target],
  .motion-demo.motion-demo--parallax [data-spring-target] {
    transform: none !important;
  }

  .motion-demo.motion-demo--parallax .motion-path { stroke-dashoffset: 0 !important; }
  .motion-demo.motion-demo--parallax .motion-word--from { opacity: 0 !important; visibility: hidden; }
  .motion-demo.motion-demo--parallax .motion-word:not(.motion-word--from) { opacity: 1 !important; filter: none !important; transform: none !important; }
}

深入了解

实现前检查

目的: 用前后景的克制速度差建立层次，同时保持主体内容稳定可读。
频率: 适合低频头图和展示区；长页面重复使用会增加视觉负担。
触发: 由页面滚动持续驱动，运动幅度与容器可见区间绑定。
进入 / 离开: 进入视口前后保持连续位置，避免在观察阈值处突然启动。
可打断性: 方向变化时直接跟随当前滚动位置，无需播放补偿动画。
手势与键盘: 不接管滚动手势；背景层设置 pointer-events 规则，避免遮挡内容操作。
减弱动效策略: 所有层固定在信息最清晰的位置，移除速度差。

可访问性

减弱动效

所有层固定在信息最清晰的位置，移除速度差。

参数参考

参数	范围 / 选项	默认值	作用
`distance`	0px–160px	48px	控制元素移动的空间距离。
`speed`	10%–80%	35%	调节速度差。
`axis`	垂直 / 水平	垂直	选择轴向。