<div class="toggle" ref="switchRef" @click.stop="toggleDark()">
   <el-icon v-show="!isDark" :size="30"><Moon /></el-icon>
   <el-icon v-show="isDark" :size="30"><Sunny /></el-icon>
 </div>

import { useDark } from '@vueuse/core';
const isDark = useDark();
//獲取切換元素的ref
const switchRef = ref<HTMLElement>();
const toggleDark = () => {
  // 若瀏覽器不支持 View Transitions
  if (!document.startViewTransition) {
    return true;
  }
  return new Promise(resolve => {
    const switchEl = switchRef.value as HTMLElement;
    const rect = switchEl.getBoundingClientRect();
    const x = rect.left + rect.width / 2;
    const y = rect.top + rect.height / 2;
    const radius = Math.hypot(Math.max(x, innerWidth - x), Math.max(y, innerHeight - y));
    const transition = document.startViewTransition(() => {
      resolve(true);
    });
    transition.ready.then(() => {
      const clipPath = [`circle(0px at ${x}px ${y}px)`, `circle(${radius}px at ${x}px ${y}px)`];
      document.documentElement.animate(
        {
          clipPath,
        },
        {
          duration: 400,
          easing: 'ease-in',
          pseudoElement: '::view-transition-new(root)',
        }
      );
      isDark.value = !isDark.value;
    });
  });
};