vs-epub.css

@page {
  margin: 8%;
  @bottom-center {
    writing-mode: horizontal-tb;
    font-size: 67%;
    content: "– " counter(page) " –";
  }
}
@page :first {
  margin: 0;
  @bottom-center {
    content: none;
  }
  @top-left {
    content: none;
  }
  @top-right {
    content: none;
  }
}

@page :left {
  @top-left {
    writing-mode: horizontal-tb;
    font-size: 75%;
    content: env(pub-title);
  }
}

@page :right {
  @top-right {
    writing-mode: horizontal-tb;
    font-size: 75%;
    content: string(sect-title);
  }
}

html, body {
  margin: 0;
}
h1,h2,h3,h4,h5,h6 {
  break-after: avoid;
}
img {
  max-width: 100vw !important;
  max-height: 100vh !important;
}

/* 以下のCSSルールは、電書協EPUB3制作ガイドなど使われている実際の日本語EPUBデータでそれなりの結果になるようにしたもの */

.p-cover img,
.titlepage img,
#cover+.full img,
body.newImgPage img.pagefit,
body.imgpage img.pagefit {
  width: 100vw !important;
  height: 100vh !important;
  object-fit: contain;
}
.v-valign-height,
.v-valign-height02,
.v-valign-height03 {
  height: 100vh !important;
}
.h-valign-width,
.h-valign-width02,
.h-valign-width03 {
  width: 100vw !important;
}

h1, h2, h3, h4,
.font-120per,
.font-130per,
.font-140per,
.font-150per,
.font-160per,
.font-170per,
.font-180per,
.font-190per,
.font-200per,
.font-250per,
.font-300per {
  string-set: sect-title content();
}
*:empty {
  string-set: none;
}