/* Make the reading column wider */
.book .book-body .page-wrapper .page-inner {
  max-width: 1400px;          /* try 1000–1200px or ~80ch for readability */
}

/* (optional) let wide tables/figures breathe a bit */
.book .book-body .page-wrapper .page-inner section.normal {
  overflow-x: visible;
}
pre, pre code { white-space: pre-wrap; }

.definition { background-color: #c1e6f7; }
.example    { background-color: #EBEBEB; }
.remark     { background-color: #bff6db; }
.theorem    { background-color: #fad7f5; }

/* Bold captions */
.definition .caption,
.example .caption,
.remark .caption,
.theorem .caption {
  font-weight: bold;
  margin: 0;
  padding: 0;
}