direction-aware-transition

方向感过渡

根据导航方向匹配进入和离开方向，维持前后关系。

预览

前进时内容沿一个方向滑动，返回时沿相反方向滑动，让导航具备方向感。

上一状态

方向感过渡

实现「方向感过渡」：根据导航方向匹配进入和离开方向，维持前后关系。参数设为时长 240ms、位移 40px、方向 left、曲线 soft。在状态发生变化时触发一次，并允许重新播放。使用语义化 HTML，CSS 作用域限定在 .motion-demo--direction-aware-transition，并挂载随组件提供的原生 JavaScript 交互运行时。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--direction-aware-transition" data-motion="direction-aware-transition" aria-label="方向感过渡 示例">
  <div class="motion-replay-scene">
    <div class="motion-state-stack"><article class="motion-state motion-state--from">上一状态</article><article class="motion-state motion-state--to">方向感过渡</article></div>
    <div class="motion-action-row"><button class="motion-replay-button" type="button" data-motion-replay>重播动效</button></div>
  </div>
</div>

motion.css

.motion-demo.motion-demo--direction-aware-transition {
  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--direction-aware-transition *, .motion-demo.motion-demo--direction-aware-transition *::before, .motion-demo.motion-demo--direction-aware-transition *::after {
  box-sizing: border-box;
}

.motion-demo.motion-demo--direction-aware-transition .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--direction-aware-transition .motion-surface strong { font-weight: 500; }

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

.motion-demo.motion-demo--direction-aware-transition .motion-line:last-child { width: 62%; }

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

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

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

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

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

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

.motion-demo.motion-demo--direction-aware-transition .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--direction-aware-transition .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--direction-aware-transition .motion-state-stack { position: relative; width: min(100%, 18rem); height: 9rem; }
.motion-demo.motion-demo--direction-aware-transition .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--direction-aware-transition .motion-state--to { background: #18181b; color: white; }

.motion-demo.motion-demo--direction-aware-transition .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--direction-aware-transition .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--direction-aware-transition .motion-text-stack { position: relative; width: min(100%, 18rem); min-height: 4rem; }
.motion-demo.motion-demo--direction-aware-transition svg { width: min(100%, 20rem); height: auto; }

.motion-demo.motion-demo--direction-aware-transition .motion-state--from { animation: motion-direction-aware-transition-out 240ms cubic-bezier(0.23, 1, 0.32, 1) both; }
.motion-demo.motion-demo--direction-aware-transition .motion-state--to { animation: motion-direction-aware-transition-in 240ms cubic-bezier(0.23, 1, 0.32, 1) both; }
@keyframes motion-direction-aware-transition-out { to { opacity: 0; transform: translateX(40px); } }
@keyframes motion-direction-aware-transition-in { from { opacity: 0; transform: translateX(-40px); } to { opacity: 1; transform: none; } }

@keyframes motion-direction-aware-transition-reduced-fade {
  from { opacity: 0.84; }
  to { opacity: 1; }
}

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

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

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

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

  .motion-demo.motion-demo--direction-aware-transition *, .motion-demo.motion-demo--direction-aware-transition *::before, .motion-demo.motion-demo--direction-aware-transition *::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--direction-aware-transition .motion-button,
  .motion-demo.motion-demo--direction-aware-transition [data-reorder-item],
  .motion-demo.motion-demo--direction-aware-transition [data-swipe-target],
  .motion-demo.motion-demo--direction-aware-transition [data-spring-target] {
    transform: none !important;
  }

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

motion.js

(() => {
  const config = {
  "id": "direction-aware-transition",
  "duration": 240,
  "distance": 40,
  "resistance": 65,
  "position": 50,
  "stiffness": 220,
  "damping": 24,
  "mass": 1,
  "velocity": 0,
  "rippleSize": 220,
  "rippleOpacity": 24,
  "dragScale": 103,
  "autoplay": false
};
  const mount = (root, config) => {

    const cleanups = [];
    const addCleanup = (callback) => cleanups.push(callback);
    const cleanup = () => {
      for (let index = cleanups.length - 1; index >= 0; index -= 1) {
        try { cleanups[index](); } catch { /* keep cleanup reentrant */ }
      }
      cleanups.length = 0;
    };
    const on = (target, type, listener, options) => {
      target.addEventListener(type, listener, options);
      addCleanup(() => target.removeEventListener(type, listener, options));
    };
    const reduced = () => root.closest(".force-reduced-motion") !== null ||
      window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    const watchReduced = (callback) => {
      const media = window.matchMedia("(prefers-reduced-motion: reduce)");
      const notify = () => callback(reduced());
      media.addEventListener("change", notify);
      const observer = typeof MutationObserver === "undefined" ? null : new MutationObserver(notify);
      let ancestor = root;
      while (observer && ancestor) {
        observer.observe(ancestor, { attributes: true, attributeFilter: ["class"] });
        ancestor = ancestor.parentElement;
      }
      addCleanup(() => {
        media.removeEventListener("change", notify);
        if (observer) observer.disconnect();
      });
    };

    const replay = root.querySelector("[data-motion-replay]");
    if (!replay) return cleanup;
    const restart = () => {
      root.getAnimations({ subtree: true }).forEach((animation) => {
        animation.cancel();
        animation.currentTime = 0;
        animation.play();
      });
    };
    addCleanup(() => root.getAnimations({ subtree: true }).forEach((animation) => {
      if (animation.playState === "paused") animation.play();
    }));
    on(replay, "click", restart);
    return cleanup;
  };
  document.querySelectorAll("[data-motion=\"direction-aware-transition\"]").forEach((root) => {
    const cleanupKey = "__motionLexiconCleanup";
    if (typeof root[cleanupKey] === "function") root[cleanupKey]();
    root[cleanupKey] = mount(root, config);
  });
})();

深入了解

实现前检查

目的: 用相反方向表达前进与返回，维持导航序列和层级关系。
频率: 适合中频步骤流、分页和历史导航；同级标签切换只在方向有意义时使用。
触发: 由 next、previous、浏览器返回或有序索引变化触发。
进入 / 离开: 前进时新内容从前方进入、旧内容向后方退出；返回时完整反转。
可打断性: 连续导航以当前进度接管，并只渲染当前位置与最新目标。
手势与键盘: 滑动翻页时方向跟随手势；按钮与键盘导航沿用同一空间规则。
减弱动效策略: 改用短交叉淡化，同时保留前进、返回标签和焦点位置。

可访问性

减弱动效

改用短交叉淡化，同时保留前进、返回标签和焦点位置。

参数参考

参数	范围 / 选项	默认值	作用
`duration`	80ms–1200ms	240ms	控制一次动效完成所需的时间。
`distance`	0px–120px	40px	控制元素移动的空间距离。
`direction`	向上 / 向下 / 向左 / 向右 / 离开	向左	选择方向。
`ease`	柔和 / 清脆 / 平稳 / 匀速	柔和	控制速度随时间变化的方式。