materio-d8/web/themes/custom/materiotheme/vuejs/components/Helper/Modal.vue

<template>
  <div class="overlay">
    <div class="modal">
      <slot></slot>
    </div>
  </div>
</template>
<script>
export default {
  name: "",
  data: () => ({

  })
}
</script>
<style lang="scss" scoped>
.overlay{
  background-color: rgba(0,0,0,0.8);
  position:fixed;
  top:0; right:0; bottom:0; left:0;
  z-index:99999;
}
.modal{
  background-color:#fff;
  position:absolute;
  width:250px;
  height:200px;
  top:0; right:0; bottom:0; left:0;
  margin:auto;
}
</style>