<div id="app">
  <div class="container">
    <h3 class="text-center" style="color:#fff">PDF Viewer</h3>
    <a href="https://res.cloudinary.com/christekh/image/upload/v1504118111/oirhtz7q6ymlf6nm6trz.pdf" target="_blank">Download</a>
    <div class="row">
      <div class="col-md-3 col-sm-3 col-xs-3 prev">
          <span class="glyphicon glyphicon-triangle-left" @click="prev()"></span>
        </div>
      <div class="col-md-6 col-sm-6 col-xs-6" v-if="preview">
        <img :src="preview" alt="" class="preview">
      </div>
      <div class="col-md-3 col-sm-3 col-xs-3 next">
          <span class="glyphicon glyphicon-triangle-right" @click="next()"></span>
        </div>
    </div>
    <div class="row pages">
      <div class="col-md-3" v-for="page in pages">
        <img :src="page.url" alt="" class="img-responsive" @click="selectImage(page.page)">
      </div>
    </div>
  </div>
</div>


html, body, #app, .container {
  height: 100%;
}

.preview {
  margin-top: 40px;
}
img {
  display: block;
  margin: auto;
  border: #E1E1E1;
  box-shadow: 0px 3px 6px 0px rgba(0,0,0,0.3);
}

.upload {
  margin-top: 30%;
  margin-left: 14%;
}

button {
  color: #687DDB;
  padding: 10px 15px;
  border: #e1e1e1;
  background: #fff;
  border-radius: 4px;
}

body {
  background: #687DDB;
}

.pages {
  margin-top: 20px;
  height: 400px;
  overflow: scroll;
}

.pages img {
  cursor: pointer;
  margin-top: 10px;
}

a {
  color: #fff;
  text-align: center;
  text-decoration: underline;
  display: block
}

a:hover {
  color: #fff;
}

.prev, .next {
  display: flex;
  align-items: center;
  justify-content: center;
}

.prev span, .next span {
  display: block;
  font-size: 25px;
  color: #fff;
  cursor: pointer;
}
new Vue({
  el: '#app',
  data: {
    preview: null,
    currIndex: 1,
    pageCount: 21,
    pages: []
  },
  mounted() {
    this.preview = `https://res.cloudinary.com/christekh/image/upload/w_350,h_400,c_fill,pg_1/oirhtz7q6ymlf6nm6trz.jpg`;
    for (let i = 1; i <= this.pageCount; i++) {
      this.pages.push(
        {
          url: `https://res.cloudinary.com/christekh/image/upload/w_200,h_250,c_fill,pg_${i}/oirhtz7q6ymlf6nm6trz.jpg`,
          page: i
        }
      )
    }
  },
  methods: {
    selectImage(page) {
      this.preview = `http://res.cloudinary.com/christekh/image/upload/w_350,h_400,c_fill,pg_${page}/oirhtz7q6ymlf6nm6trz.jpg`
    },
    prev() {
      if(this.currIndex <= 1) return;
      this.currIndex -= 1;
      this.preview = `http://res.cloudinary.com/christekh/image/upload/w_350,h_400,c_fill,pg_${this.currIndex}/oirhtz7q6ymlf6nm6trz.jpg`
    },
    next() {
      if(this.currIndex >= this.pageCount) return;
      this.currIndex += 1;
      this.preview = `http://res.cloudinary.com/christekh/image/upload/w_350,h_400,c_fill,pg_${this.currIndex}/oirhtz7q6ymlf6nm6trz.jpg`
    }
  }
});

External CSS

  1. https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/vue/2.3.4/vue.min.js
  2. https://widget.cloudinary.com/global/all.js