/* ------------------------------
   Base book typography
   ------------------------------ */

body {
  font-family: "Libertinus Serif", Georgia, serif;
  max-width: 42em;
  margin: auto;
  padding: 3rem 1.25rem;
  line-height: 1.65;
  background: #fff;
  color: #111;
}

/* ------------------------------
   Headings
   ------------------------------ */

h1, h2, h3, h4 {
  font-family: "Libertinus Sans", sans-serif;
  font-weight: 600;
  margin-top: 2em;
  margin-bottom: 0.6em;
}

h1 {
  font-size: 2.1rem;
  border-bottom: 2px solid #ddd;
  padding-bottom: 0.4rem;
}

h2 {
  font-size: 1.6rem;
}

h3 {
  font-size: 1.25rem;
}

/* ------------------------------
   Front matter page
   ------------------------------ */

.frontmatter {
  text-align: center;
  margin-top: 10vh;
}

.frontmatter img {
  max-width: 30%;
  margin: 2rem auto;
  display: block;
}

/* ------------------------------
   Lists / paragraphs
   ------------------------------ */

p {
  margin: 1em 0;
}

ul, ol {
  padding-left: 1.5em;
  margin: 1em 0;
}

/* ------------------------------
   Math block spacing
   ------------------------------ */

.math.display {
  margin: 1.2em 0;
}

/* ------------------------------
   Callouts (final tuned spacing)
   ------------------------------ */

.callout-established,
.callout-proposed,
.callout-speculative {
  border-radius: 6px;
  padding: 5px;  /* internal padding */
  margin-top: 5px;     /* external spacing tightened */
  margin-bottom: 5px;
  border-left: 6px solid;
  background: #fefefe;
}

/* Title line */
.callout-established p:first-child strong,
.callout-proposed p:first-child strong,
.callout-speculative p:first-child strong {
  display: block;
  font-family: "Libertinus Sans", sans-serif;
  font-weight: 600;
  font-size: 1.05rem;
  margin-bottom: 5px;
}

/* Paragraphs inside callouts */
.callout-established p,
.callout-proposed p,
.callout-speculative p {
  margin-top: 5px;
  margin-bottom: 5px;
  line-height: 1.45;  /* slightly condensed text spacing */
}

/* Remove top margin on first paragraph, bottom on last */
.callout-established p:first-child,
.callout-proposed p:first-child,
.callout-speculative p:first-child {
  margin-top: 0;
}
.callout-established p:last-child,
.callout-proposed p:last-child,
.callout-speculative p:last-child {
  margin-bottom: 0;
}

/* Math inside callouts */
.callout-established .math.display,
.callout-proposed .math.display,
.callout-speculative .math.display {
  margin: 0.4em 0;
}

/* Colors */
.callout-established {
  background: #e8f7e8;
  border-left-color: #3a8d3a;
}
.callout-proposed {
  background: #e8f0ff;
  border-left-color: #3b6dd8;
}
.callout-speculative {
  background: #f7e8ff;
  border-left-color: #8b2be2;
}


/* ------------------------------
   Images (in body content)
   ------------------------------ */

img {
  max-width: 100%;
  display: block;
  margin: 1.2em auto;
}

/* ------------------------------
   Blockquotes (normal ones)
   ------------------------------ */

blockquote {
  border-left: 4px solid #ccc;
  padding-left: 1em;
  font-style: italic;
  color: #444;
}

/* ------------------------------
   Horizontal rule
   ------------------------------ */

hr {
  margin: 3rem 0;
  border: none;
  border-top: 1px solid #ddd;
}

/* ------------------------------
   Code (rare in your book)
   ------------------------------ */

code {
  background: #f3f3f3;
  padding: 0.1em 0.3em;
  border-radius: 4px;
  font-size: 0.95em;
}