/* ============================================================
   Org-Mode with Emacs — Book Stylesheet
   ============================================================ */

:root {
  --bg:        #fafaf8;
  --bg-alt:    #f0efe8;
  --bg-code:   #1e1e2e;
  --fg:        #1a1a1a;
  --fg-muted:  #555;
  --accent:    #7c6fcd;
  --accent-dk: #5a4fa3;
  --link:      #5a4fa3;
  --border:    #d8d6cc;
  --sidebar-w: 240px;
  --content-w: 760px;
  --font-body: 'IBM Plex Serif', Georgia, serif;
  --font-ui:   'IBM Plex Sans', system-ui, sans-serif;
  --font-mono: 'IBM Plex Mono', 'Fira Code', monospace;
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

/* ── Base ── */
html { font-size: 18px; scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  line-height: 1.75;
}

/* ── Fixed sidebar ── */
#org-nav {
  position: fixed;
  top: 0; left: 0;
  width: var(--sidebar-w);
  height: 100vh;
  overflow-y: auto;
  background: var(--bg-alt);
  border-right: 1px solid var(--border);
  padding: 2rem 1.25rem;
  font-family: var(--font-ui);
  font-size: 0.82rem;
  z-index: 100;
}

#org-nav .nav-title {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1.5rem;
  display: block;
  text-decoration: none;
}

#org-nav ol { list-style: none; padding: 0; }
#org-nav li { margin-bottom: 0.3rem; }

#org-nav a {
  color: var(--fg-muted);
  text-decoration: none;
  display: block;
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  line-height: 1.4;
  transition: color 0.15s, background 0.15s;
}

#org-nav a:hover { color: var(--accent); background: rgba(124,111,205,0.08); }

#org-nav .nav-index {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}
#org-nav .nav-index a { color: var(--accent); font-weight: 600; }

/* ── Page sections — all shift right past the fixed sidebar ── */
#preamble,
#content,
#postamble {
  margin-left: var(--sidebar-w);
}

/* ── Preamble (org wraps our HTML in <div id="preamble">) ── */
#preamble {
  padding: 1.25rem 2.5rem 0;
  max-width: calc(var(--sidebar-w) + var(--content-w) + 5rem);
  font-family: var(--font-ui);
}

/* ── Main content ── */
#content {
  padding: 2.5rem 2.5rem 4rem;
  max-width: calc(var(--sidebar-w) + var(--content-w) + 5rem);
}

/* ── Footer ── */
#postamble {
  padding: 1.25rem 2.5rem 2rem;
  max-width: calc(var(--sidebar-w) + var(--content-w) + 5rem);
  border-top: 1px solid var(--border);
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--fg-muted);
}

/* ── Typography ── */
h1, h2, h3, h4, h5 {
  font-family: var(--font-ui);
  font-weight: 700;
  line-height: 1.25;
  color: var(--fg);
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
}

h1 {
  font-size: 2rem;
  margin-top: 0;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent);
}
h2 { font-size: 1.45rem; color: var(--accent-dk); }
h3 { font-size: 1.15rem; }
h4 { font-size: 1rem; }

p { margin-bottom: 1.1rem; }

a { color: var(--link); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--accent); }

strong, b { font-weight: 700; }
em, i     { font-style: italic; }
del, s    { text-decoration: line-through; color: var(--fg-muted); }

/* ── Inline table of contents ── */
#table-of-contents {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1.25rem 1.75rem;
  margin-bottom: 2rem;
  font-family: var(--font-ui);
  font-size: 0.88rem;
}
#table-of-contents h2 {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--fg-muted);
  margin-top: 0;
  margin-bottom: 0.75rem;
}
#table-of-contents ul { list-style: none; padding: 0; }
#table-of-contents ul ul { padding-left: 1.25rem; margin-top: 0.2rem; }
#table-of-contents li { margin-bottom: 0.2rem; }
#table-of-contents a { color: var(--link); text-decoration: none; }
#table-of-contents a:hover { text-decoration: underline; }

/* ── Lists ── */
ul, ol { padding-left: 1.75rem; margin-bottom: 1rem; }
li { margin-bottom: 0.25rem; }
li p { margin-bottom: 0.25rem; }

/* ── Code ── */
code, kbd, samp {
  font-family: var(--font-mono);
  font-size: 0.86em;
  background: rgba(0,0,0,0.06);
  padding: 0.1em 0.35em;
  border-radius: 3px;
  color: #a72145;
}

pre {
  background: var(--bg-code);
  color: #cdd6f4;
  font-family: var(--font-mono);
  font-size: 0.83rem;
  line-height: 1.6;
  padding: 1.25rem 1.5rem;
  border-radius: 6px;
  overflow-x: auto;
  margin: 1rem 0 1.5rem;
}
pre code { background: none; padding: 0; color: inherit; font-size: inherit; border-radius: 0; }
.org-src-container { margin: 1rem 0 1.5rem; }
.org-src-container pre { margin: 0; }

/* ── Blockquote ── */
blockquote {
  border-left: 4px solid var(--accent);
  margin: 1.5rem 0;
  padding: 0.75rem 1.5rem;
  background: rgba(124,111,205,0.05);
  font-style: italic;
  color: var(--fg-muted);
  border-radius: 0 4px 4px 0;
}
blockquote p:last-child { margin-bottom: 0; }

/* ── Tables ── */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.88rem;
  font-family: var(--font-ui);
}
th {
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  padding: 0.55rem 0.85rem;
  text-align: left;
}
td { padding: 0.45rem 0.85rem; border-bottom: 1px solid var(--border); }
tr:nth-child(even) td { background: var(--bg-alt); }

/* ── Horizontal rule ── */
hr { border: none; border-top: 1px solid var(--border); margin: 2rem 0; }

/* ── Chapter prev/next nav ── */
.chapter-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  font-family: var(--font-ui);
  font-size: 0.88rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0.5rem;
}
.chapter-nav a {
  padding: 0.4rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--link);
  text-decoration: none;
  transition: border-color 0.15s, background 0.15s;
}
.chapter-nav a:hover { border-color: var(--accent); background: rgba(124,111,205,0.06); }

/* ── Responsive ── */
@media (max-width: 860px) {
  #org-nav { display: none; }
  #preamble, #content, #postamble { margin-left: 0; }
  #preamble, #content, #postamble { padding-left: 1.25rem; padding-right: 1.25rem; }
}

@media print {
  #org-nav, #preamble { display: none; }
  #content { margin: 0; padding: 0; }
  pre { white-space: pre-wrap; }
}