/* ── Color palette ── */
:root {
  --crimson: #A51C30;
  --crimson-dark: #8C1515;
  --text: #1E1E1E;
  --text-light: #555555;
  --bg: #FFFFFF;
  --bg-warm: #F7F5F2;
  --code-bg: #F3F4F4;
  --border: #E0DCDA;
}

/* ── Reset & base ── */
*, *::before, *::after { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

/* ── Layout ── */
header, nav, .content, footer {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ── Header ── */
header {
  padding-top: 2rem;
  padding-bottom: 0.5rem;
  text-align: center;
}
header h1 {
  font-size: 1.8rem;
  color: var(--crimson-dark);
  margin: 0.5rem 0 0.25rem;
}
header .subtitle {
  color: var(--text-light);
  font-size: 0.95rem;
  margin: 0;
}

/* ── Navigation ── */
nav {
  text-align: center;
  padding: 0.75rem 1.5rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}
nav a {
  display: inline-block;
  margin: 0.25rem 0.6rem;
  text-decoration: none;
  color: var(--crimson);
  font-size: 0.95rem;
}
nav a:hover { text-decoration: underline; }
nav a.active {
  font-weight: bold;
  text-decoration: underline;
}

/* ── Content area ── */
.content {
  padding-top: 0.5rem;
  padding-bottom: 2rem;
}

/* ── Headings ── */
h2 {
  color: var(--crimson-dark);
  border-bottom: 2px solid var(--border);
  padding-bottom: 0.35rem;
  margin-top: 2rem;
}
h3 {
  color: var(--crimson);
  margin-top: 1.5rem;
}
h4 {
  color: var(--text);
  margin-top: 1.25rem;
  font-size: 1rem;
}

/* ── Links ── */
a { color: var(--crimson); }
a:hover { color: var(--crimson-dark); }

/* ── Session cards (home page) ── */
.session-cards {
  display: grid;
  gap: 1.25rem;
  margin: 1.5rem 0;
}
.session-card {
  display: block;
  text-decoration: none;
  color: var(--text);
  background: var(--bg-warm);
  border: 1px solid var(--border);
  border-left: 4px solid var(--crimson);
  border-radius: 4px;
  padding: 1rem 1.25rem;
  transition: border-color 0.2s;
}
.session-card:hover {
  border-left-color: var(--crimson-dark);
}
.session-card h3 {
  margin: 0 0 0.25rem;
  font-size: 1.05rem;
}
.session-card p {
  margin: 0;
  color: var(--text-light);
  font-size: 0.9rem;
}

/* ── Code blocks ── */
pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1rem;
  overflow-x: auto;
  white-space: pre-wrap;
  word-wrap: break-word;
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.88rem;
  line-height: 1.5;
}
code {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.88rem;
}
p code, li code {
  background: var(--code-bg);
  padding: 0.15em 0.4em;
  border-radius: 3px;
}

/* ── Callout / disclaimer boxes ── */
.callout {
  border: 2px solid var(--crimson);
  background: #FFF3F4;
  border-radius: 4px;
  padding: 0.75rem 1rem;
  margin: 1rem 0;
}
.callout.green {
  background: #d4edda;
  border-color: #28a745;
}
.callout.blue {
  background: #d1ecf1;
  border-color: #17a2b8;
}
.callout.yellow {
  background: #fff3cd;
  border-color: #ff9800;
}
.callout strong { display: block; margin-bottom: 0.25rem; }

/* ── Resource lists ── */
ul.resources {
  list-style: none;
  padding: 0;
}
ul.resources li {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border);
}
ul.resources li:last-child { border-bottom: none; }
ul.resources .desc {
  display: block;
  color: var(--text-light);
  font-size: 0.9rem;
}

/* ── Images ── */
.figure {
  text-align: center;
  margin: 1.5rem 0;
}
.figure img {
  max-width: 700px;
  width: 100%;
  border: 1px solid #ddd;
  border-radius: 6px;
}
.figure .caption {
  font-size: 0.8rem;
  color: var(--text-light);
  font-style: italic;
  margin-top: 0.35rem;
}

/* ── Tables ── */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
}
th {
  background: var(--crimson-dark);
  color: #fff;
  text-align: left;
  padding: 0.6rem 0.75rem;
}
td {
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--border);
}
tr:nth-child(even) { background: var(--bg-warm); }

/* ── Buttons ── */
.btn {
  display: inline-block;
  background: var(--crimson);
  color: #fff;
  text-decoration: none;
  padding: 0.5rem 1.25rem;
  border-radius: 4px;
  font-family: -apple-system, Helvetica, Arial, sans-serif;
  font-size: 0.9rem;
  transition: background 0.2s;
}
.btn:hover { background: var(--crimson-dark); color: #fff; }

/* ── Footer ── */
footer {
  text-align: center;
  padding: 1.5rem;
  color: var(--text-light);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
  margin-top: 2rem;
}

/* ── Responsive ── */
@media (max-width: 600px) {
  header h1 { font-size: 1.4rem; }
  nav a { display: block; margin: 0.3rem 0; }
  .content { padding-left: 1rem; padding-right: 1rem; }
}