/* layout */
html,body { margin:0; height:100%; background:#f8f5f0; font-family: Georgia, serif; }
#book-wrap { position:relative; min-height:100vh; display:flex; align-items:center; justify-content:center; padding:2rem; }

/* livre */
#book { 
  width:800px; 
  height:600px; 
  margin: 0 auto;
  display: block;
}
#book .page {
  width:400px; height:600px;
  background:#fff; border:1px solid #ddd; box-sizing:border-box; overflow:hidden;
}
.page-inner { padding:2rem; line-height:1.55; }
.page-inner h2 { margin:0 0 1rem; }

/* flèches */
.arrow{
  position:absolute; top:50%; transform:translateY(-50%);
  font-size:2rem; padding:.4rem .8rem;
  background:rgba(0,0,0,.35); color:#fff; border:0; border-radius:50%;
  cursor:pointer; z-index:20;
}
.arrow-left{ left:10px; } .arrow-right{ right:10px; }
.arrow[disabled]{ opacity:.4; cursor:not-allowed; }

/* responsive simple */
@media (max-width: 960px){
  #book{ width:600px; height:450px; }
  #book .page{ width:300px; height:450px; }
}
@media (max-width: 720px){
  #book{ width:400px; height:600px; }
  #book .page{ width:400px; height:600px; }
}

/* Texte paragr. générés depuis du brut */
.page-inner p { margin: 0 0 1rem; }
.page-inner p:last-child { margin-bottom: 0; }