remarkで作ったスライドをPDF出力する方法 ref: https://qiita.com/y-temp4/items/96b75d9f27a85b598f34

file0.css

@page {
  size: 1210px 681px;
  margin: 0;
}

@media print {
  .remark-slide-scaler {
    width: 100% !important;
    height: 100% !important;
    transform: scale(1) !important;
    top: 0 !important;
    left: 0 !important;
  }
}