Vue.js 重新加载页面正在 vue 组件中的插槽上闪烁内容

.body {
			padding: 2em;
			text-align: center;
			display: table-cell;
		  	vertical-align: middle;
		}

		.modal-mask {
		  position: absolute;
		  z-index: 9998;
		  top: 0;
		  left: 0;
		  width: 100%;
		  height: 100%;
		  background-color: rgba(0, 0, 0, .5);
		  display: table;
		  transition: opacity .3s ease;
		}

		.modal-wrapper {
		  display: table-cell;
		  vertical-align: middle;
		}

		.modal-container {
		  width: 70%;
		  margin: 1em auto;
		  padding: 20px 30px;
		  background-color: #fff;
		  border-radius: 2px;
		  box-shadow: 0 2px 8px rgba(0, 0, 0, .33);
		  transition: all .3s ease;
		  font-family: Helvetica, Arial, sans-serif;
		}

		.modal-header h3 {
		  margin-top: 0;
		  color: #42b983;
		}

		.modal-body {
		  margin: 20px 0;
		}

		.modal-default-button {
		  float: right;
		}


		/*
		 * The following styles are auto-applied to elements with
		 * transition="modal" when their visibility is toggled
		 * by Vue.js.
		 *
		 * You can easily play with the modal transition by editing
		 * these styles.
		 */

		.modal-enter {
		  opacity: 0;
		}

		.modal-leave-active {
		  opacity: 0;
		}

		.modal-enter .modal-container,
		.modal-leave-active .modal-container {
		  -webkit-transform: scale(1.1);
		  transform: scale(1.1);
		}

<!-- template for the modal component -->
<script type="text/x-template" id="modal-template">
  <transition name="modal">
    <div class="modal-mask">
      <div class="modal-wrapper">
        <div class="modal-container">

          <div class="modal-header">
            <slot name="header">
              default header
            </slot>
            <button class="modal-default-button" @click="$emit('close')">Close</button>
          </div>

          <div class="modal-body">
            <slot name="body">
              default body
            </slot>
          </div>

          <div class="modal-footer">
            <slot name="footer">
              default footer
              <button class="modal-default-button" @click="$emit('close')">
                OK
              </button>
            </slot>
          </div>
        </div>
      </div>
    </div>
  </transition>
</script>

<!-- app -->
<div id="app">
  <button id="show-modal" @click="showModal = true">Show Modal</button>
  <!-- use the modal component, pass in the prop -->
  <modal v-if="showModal" @close="showModal = false">
    <!--
      you can use custom content here to overwrite
      default content
    -->
    <div slot="body">
      <div class="modal-body">
        <h4>Text in a modal</h4>
        <p>Duis mollis, est non commodo luctus, nisi erat porttitor ligula.</p>
        <h4>Popover in a modal</h4>
        <p>This <a href="#" class="btn btn-default popover-test" role="button" title="" data-content="And here's some amazing content. It's very engaging. right?" data-original-title="A Title">button</a> should trigger a popover on click.</p>
        <h4>Tooltips in a modal</h4>
        <p><a href="#" class="tooltip-test" title="" data-original-title="Tooltip">This link</a> and <a href="#" class="tooltip-test" title="" data-original-title="Tooltip">that link</a> should have tooltips on hover.</p>
        <hr>
        <h4>Overflowing text to show scroll behavior</h4>
        <p>Cras mattis consectetur purus sit amet fermentum. Cras justo odio, dapibus ac facilisis in, egestas eget quam. Morbi leo risus, porta ac consectetur ac, vestibulum at eros.</p>
        <p>Praesent commodo cursus magna, vel scelerisque nisl consectetur et. Vivamus sagittis lacus vel augue laoreet rutrum faucibus dolor auctor.</p>
        <p>Aenean lacinia bibendum nulla sed consectetur. Praesent commodo cursus magna, vel scelerisque nisl consectetur et. Donec sed odio dui. Donec ullamcorper nulla non metus auctor fringilla.</p>
        <p>Cras mattis consectetur purus sit amet fermentum. Cras justo odio, dapibus ac facilisis in, egestas eget quam. Morbi leo risus, porta ac consectetur ac, vestibulum at eros.</p>
        <p>Praesent commodo cursus magna, vel scelerisque nisl consectetur et. Vivamus sagittis lacus vel augue laoreet rutrum faucibus dolor auctor.</p>
        <p>Aenean lacinia bibendum nulla sed consectetur. Praesent commodo cursus magna, vel scelerisque nisl consectetur et. Donec sed odio dui. Donec ullamcorper nulla non metus auctor fringilla.</p>
        <p>Cras mattis consectetur purus sit amet fermentum. Cras justo odio, dapibus ac facilisis in, egestas eget quam. Morbi leo risus, porta ac consectetur ac, vestibulum at eros.</p>
        <p>Praesent commodo cursus magna, vel scelerisque nisl consectetur et. Vivamus sagittis lacus vel augue laoreet rutrum faucibus dolor auctor.</p>
        <p>Aenean lacinia bibendum nulla sed consectetur. Praesent commodo cursus magna, vel scelerisque nisl consectetur et. Donec sed odio dui. Donec ullamcorper nulla non metus auctor fringilla.</p>
      </div>
    </div>
    <h3 slot="header">custom header</h3>
  </modal>
</div>

<script src="https://unpkg.com/vue@latest/dist/vue.js"></script>

<script>
	// register modal component
	Vue.component('modal', {
	  template: '#modal-template'
	})

	// start app
	new Vue({
	  el: '#app',
	  data: {
	    showModal: false
	  }
	})
</script>