<div style="display:flex; justify-content:center; align-items:flex-start;">
  <iframe
    id="pdf-frame"
    src="https://drive.google.com/file/d/1JDhm6IASRLVeq1XDDgelHHkdHKq4dLPs/preview"
    style="display:block; border:0; width:70%; height:800px; max-width:95vw;"
    allow="autoplay">
  </iframe>
</div>

<script>
(function () {
  var PAGE_ASPECT  = 0.85;
  var BOTTOM_MARGIN = 16;
  var SIDE_RATIO    = 0.95;

  function resizePDF() {
    var ifr = document.getElementById('pdf-frame');
    if (!ifr) return;

    var vw = window.innerWidth;
    var vh = window.innerHeight;
    var topOffset = ifr.getBoundingClientRect().top;

    var availH = Math.max(150, vh - topOffset - BOTTOM_MARGIN);
    var availW = vw * SIDE_RATIO;

    var h = availH;
    var w = h * PAGE_ASPECT;
    if (w > availW) { 
      w = availW;
      h = w / PAGE_ASPECT;
      if (h > availH) { h = availH; w = h * PAGE_ASPECT; }
    }

    ifr.style.width  = Math.round(w) + 'px';
    ifr.style.height = Math.round(h) + 'px';
  }
  function run() { resizePDF(); resizePDF(); }

  window.addEventListener('load', run);
  window.addEventListener('resize', resizePDF);
  if (document.readyState === 'complete') run();
})();
</script>
<style>
@media screen and (max-width:767px) {
    iframe[src*="drive"] {
    width: 100% !important;
}
}
</style>