:root {
  --bg: #fafaf7;
  --bg-elevated: #ffffff;
  --fg: #1d1d1b;
  --muted: #6b6b66;
  --accent: #8b2c1f;
  --rule: #d8d6cf;
  --code-bg: #efece4;
  --nav-bg: rgba(250,250,247,0.92);
  --max: 38rem;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16161a;
    --bg-elevated: #1d1d22;
    --fg: #e8e6df;
    --muted: #999791;
    --accent: #d4805a;
    --rule: #2f2f35;
    --code-bg: #1f1f24;
    --nav-bg: rgba(22,22,26,0.92);
  }
}
* { box-sizing: border-box; }
html { font-size: 18px; scroll-behavior: smooth; scroll-padding-top: 5rem; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Sticky nav */
header.sticky-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--rule);
}
.nav-inner {
  max-width: 56rem;
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}
.nav-brand {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--fg);
  text-decoration: none;
  letter-spacing: -0.01em;
}
.sticky-nav nav {
  display: flex;
  gap: 1.25rem;
  font-size: 0.9rem;
}
.sticky-nav nav a {
  color: var(--muted);
  text-decoration: none;
  padding: 0.25rem 0;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}
.sticky-nav nav a:hover { color: var(--fg); }
.sticky-nav nav a.active {
  color: var(--fg);
  border-bottom-color: var(--accent);
}
.sticky-nav nav a.nav-external { color: var(--muted); font-size: 0.8rem; }
@media (max-width: 600px) {
  .nav-inner { padding: 0.5rem 1rem; }
  .sticky-nav nav { gap: 0.75rem; font-size: 0.8rem; }
  .nav-brand { font-size: 0.85rem; }
}

main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}
main.wide { max-width: 56rem; }

/* Landing page */
.prose-narrow {
  max-width: 38rem;
  margin: 0 auto;
}
header.intro {
  margin: 0 0 1.5rem;
}
header.intro h1 {
  font-size: 2.2rem;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}
header.intro .tagline {
  color: var(--muted);
  font-size: 1.1rem;
  margin: 0 0 1rem;
}
.cards {
  display: grid;
  gap: 1.25rem;
  margin: 2.5rem 0;
}
@media (min-width: 800px) {
  body.home main, body.wide main { max-width: 56rem; }
  body.home .cards { grid-template-columns: repeat(3, 1fr); }
}
.card {
  background: var(--bg-elevated);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--fg);
  transition: border-color 0.15s, transform 0.15s;
}
.card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}
.card .card-label, .card .tier-label {
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.5rem;
  display: block;
}
.card h2 {
  font-size: 1.2rem;
  margin: 0 0 0.75rem;
  letter-spacing: -0.01em;
}
.card p {
  color: var(--muted);
  font-size: 0.95rem;
  margin: 0 0 1rem;
  flex-grow: 1;
}
.card .card-meta, .card .meta {
  font-size: 0.8rem;
  color: var(--muted);
  border-top: 1px solid var(--rule);
  padding-top: 0.75rem;
  margin-top: auto;
  margin-bottom: 0;
}

/* Tier-page header */
.tier-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--rule);
}
.tier-header .tier-label {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
  font-weight: 600;
}
.tier-header h1 {
  font-size: 2rem;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}
.tier-header .meta {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0;
}

/* Audio block — now at top of page */
.audio-block {
  background: var(--code-bg);
  padding: 1rem 1.25rem;
  border-radius: 6px;
  margin: 0 0 2.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}
.audio-block .label {
  font-size: 0.85rem;
  color: var(--muted);
  white-space: nowrap;
}
.audio-block .label strong { color: var(--fg); }
.audio-block audio {
  flex: 1;
  min-width: 250px;
  height: 36px;
}

/* Content */
h1, h2, h3 { letter-spacing: -0.015em; }
h2 { font-size: 1.45rem; margin-top: 2.5rem; }
h3 { font-size: 1.15rem; margin-top: 2rem; }
p, ul, ol { margin: 1rem 0; }
ul, ol { padding-left: 1.5rem; }
li { margin: 0.4rem 0; }
em { color: var(--muted); font-style: italic; }
strong { color: var(--fg); }
a { color: var(--accent); }
hr { border: none; border-top: 1px solid var(--rule); margin: 2.5rem 0; }
blockquote {
  border-left: 3px solid var(--accent);
  margin: 1.5rem 0;
  padding: 0.5rem 0 0.5rem 1.25rem;
  color: var(--muted);
}
code {
  background: var(--code-bg);
  padding: 0.1em 0.35em;
  border-radius: 3px;
  font-size: 0.9em;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}
pre {
  background: var(--code-bg);
  padding: 1rem;
  border-radius: 4px;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.5;
}
pre code { background: none; padding: 0; }
table {
  border-collapse: collapse;
  width: 100%;
  margin: 1.5rem 0;
  font-size: 0.95rem;
  display: block;
  overflow-x: auto;
}
th, td {
  border: 1px solid var(--rule);
  padding: 0.5rem 0.75rem;
  text-align: left;
  vertical-align: top;
}
th { background: var(--code-bg); }

/* Prev/next footer between tiers */
nav.tier-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 4rem 0 2rem;
  padding-top: 2rem;
  border-top: 1px solid var(--rule);
}
nav.tier-nav a {
  display: block;
  padding: 1rem 1.25rem;
  background: var(--bg-elevated);
  border: 1px solid var(--rule);
  border-radius: 6px;
  text-decoration: none;
  color: var(--fg);
  transition: border-color 0.15s;
}
nav.tier-nav a:hover { border-color: var(--accent); }
nav.tier-nav .dir {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.25rem;
}
nav.tier-nav .title, nav.tier-nav .label {
  display: block;
  font-weight: 500;
}
nav.tier-nav .next { text-align: right; }
nav.tier-nav .placeholder { visibility: hidden; }
nav.tier-nav a.disabled {
  opacity: 0.4;
  pointer-events: none;
  cursor: default;
}

.meta-bar {
  font-size: 0.85rem;
  color: var(--muted);
  margin: 0 0 2rem;
  padding: 0.75rem 1rem;
  background: var(--code-bg);
  border-radius: 4px;
}

footer {
  max-width: var(--max);
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-size: 0.9rem;
  text-align: center;
}
footer p { margin: 0.5rem 0; }