<div class="modal" v-if="modalStep === 1">
<p>第一個對話框</p>
<button @click="modalStep =2">下一步</button>
</div>
<div class="modal" v-if="modalStep === 2">
<p>第二個對話框</p>
<button @click="modalStep =3">下一步</button>
</div>
<div class="modal" v-if="modalStep === 3">
<p>第三個對話框</p>
<button @click="modalStep =0">下一步</button>
</div>
data: modalStep: 1,
效果: