Efficiently Teleporting Modals and Overlays in Vue 3

// components/MyModal.vue
<template>
  <Teleport to="body">
    <transition name="modal-fade">
      <div v-if="isOpen" class="modal-backdrop" @click.self="closeModal">
        <div class="modal-content">
          <h3>{{ title }}</h3>
          <slot></slot>
          <button @click="closeModal">Close</button>
        </div>
      </div>
    </transition>
  </Teleport>
</template>

<script setup>
import { defineProps, defineEmits } from 'vue';

const props = defineProps({
  isOpen: {
    type: Boolean,
    default: false,
  },
  title: {
    type: String,
    default: 'Modal Title',
  },
});

const emit = defineEmits(['update:isOpen']);

const closeModal = () => {
  emit('update:isOpen', false);
};
</script>

<style scoped>
.modal-fade-enter-active, .modal-fade-leave-active {
  transition: opacity 0.3s ease;
}
.modal-fade-enter-from, .modal-fade-leave-to {
  opacity: 0;
}

.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(0, 0, 0, 0.5);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000; /* Ensure it's on top */
}

.modal-content {
  background-color: white;
  padding: 30px;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  min-width: 300px;
  max-width: 80%;
  z-index: 1001;
}
</style>

// App.vue
<template>
  <div>
    <h1>Teleport Example</h1>
    <button @click="isModalOpen = true">Open Modal</button>

    <MyModal :is-open="isModalOpen" @update:is-open="isModalOpen = $event" title="Important Notice">
      <p>This content is rendered inside the modal, but the modal itself is teleported to the document body.</p>
      <p>This helps avoid z-index conflicts with parent components.</p>
    </MyModal>

    <div style="margin-top: 50px; padding: 20px; border: 1px dashed #ccc; background-color: #f0f0f0;">
      <p>This is some content in the main app.</p>
      <p>The modal opened above it, but is not a direct child in the DOM hierarchy here.</p>
    </div>
  </div>
</template>

<script setup>
import { ref } from 'vue';
import MyModal from './components/MyModal.vue';

const isModalOpen = ref(false);
</script>