@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,400;9..144,600;9..144,700&family=Inter:wght@400;500;600&family=IBM+Plex+Mono:wght@400;500&display=swap');

:root {
  --ink: #1C1A17;
  --ink-soft: #262320;
  --paper: #F6F1E6;
  --paper-soft: #ECE5D4;
  --paper-line: #DAD0B8;
  --text: #2A2622;
  --text-muted: #83796A;
  --accent: #5F7A52;
  --accent-strong: #4C6542;
  --gold: #C9A15A;
  --danger: #B5573F;

  --font-display: 'Fraunces', Georgia, 'Times New Roman', serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'IBM Plex Mono', 'SF Mono', Consolas, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--font-body);
  -webkit-font-smoothing: antialiased;
}

body {
  background-image: radial-gradient(var(--paper-line) 1px, transparent 1px);
  background-size: 22px 22px;
  background-attachment: fixed;
  min-height: 100vh;
}

a { color: var(--accent-strong); }
a:hover { color: var(--gold); }

.layout {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  min-height: 100vh;
}

/* ---- Spine: the signature element, a notebook binding used as nav ---- */
.spine {
  position: sticky;
  top: 0;
  height: 100vh;
  background: var(--ink);
  color: var(--paper);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 28px 0;
  border-right: 1px solid var(--paper-line);
}

.spine-mark {
  display: flex;
  flex-direction: column;
  gap: 5px;
  margin-bottom: 34px;
}
.spine-mark span {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--gold);
  display: block;
}

.spine-holes {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  align-items: center;
  padding: 6px 0;
}
.spine-holes::before,
.spine-holes::after,
.spine-holes i {
  content: '';
  display: block;
}

.spine-nav {
  display: flex;
  flex-direction: column;
  gap: 26px;
  align-items: center;
}
.spine-nav a {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  transform: rotate(180deg);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  text-decoration: none;
  padding: 10px 4px;
  border-radius: 4px;
  transition: color .15s ease, background .15s ease;
}
.spine-nav a:hover { color: var(--paper); background: rgba(246,241,230,.06); }
.spine-nav a.active { color: var(--gold); }

.spine-dots {
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.spine-dots span {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--paper-line);
  opacity: .5;
}

/* ---- Content ---- */
.content {
  padding: 64px 28px 96px;
  display: flex;
  justify-content: center;
}
.page {
  width: 100%;
  max-width: 660px;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--accent-strong);
  margin: 0 0 14px;
}

h1 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(34px, 5vw, 48px);
  line-height: 1.08;
  margin: 0 0 18px;
  letter-spacing: -0.01em;
}

h2 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 24px;
  margin: 44px 0 12px;
  padding-top: 20px;
  border-top: 1px solid var(--paper-line);
}
.page > h2:first-of-type { border-top: none; padding-top: 0; }

h3 {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 15px;
  margin: 22px 0 8px;
}

.lede {
  font-size: 18px;
  line-height: 1.6;
  color: var(--text);
  max-width: 54ch;
}

p, li {
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--text);
}
.text-muted, .meta { color: var(--text-muted); }

.meta {
  font-family: var(--font-mono);
  font-size: 12.5px;
  margin-top: -6px;
  margin-bottom: 40px;
}

ul.plain { padding-left: 20px; }
ul.plain li { margin-bottom: 8px; }

.card-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin: 36px 0 8px;
}
.feature {
  background: var(--paper);
  border: 1px solid var(--paper-line);
  border-radius: 10px;
  padding: 18px 18px 16px;
}
.feature .feature-mark {
  width: 8px; height: 8px;
  border-radius: 2px;
  background: var(--accent);
  margin-bottom: 10px;
}
.feature h3 { margin: 0 0 6px; font-size: 14.5px; }
.feature p { font-size: 13.5px; margin: 0; color: var(--text-muted); line-height: 1.55; }

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 36px 0 8px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 14px;
  text-decoration: none;
  padding: 12px 20px;
  border-radius: 8px;
  border: 1px solid var(--ink);
  color: var(--ink);
}
.btn.primary { background: var(--ink); color: var(--paper); }
.btn.primary:hover { background: var(--accent-strong); border-color: var(--accent-strong); color: var(--paper); }
.btn.ghost:hover { background: var(--paper-soft); color: var(--ink); }

.callout {
  background: var(--paper-soft);
  border-left: 3px solid var(--gold);
  border-radius: 6px;
  padding: 16px 18px;
  margin: 18px 0;
  font-size: 14.5px;
}
.callout p { margin: 0; font-size: 14.5px; }
.callout code { font-family: var(--font-mono); font-size: 13px; background: rgba(0,0,0,.05); padding: 1px 6px; border-radius: 4px; }

code, .mono { font-family: var(--font-mono); font-size: 13.5px; }

hr.rule {
  border: none;
  border-top: 1px solid var(--paper-line);
  margin: 48px 0 32px;
}

footer.page-footer {
  margin-top: 56px;
  padding-top: 24px;
  border-top: 1px solid var(--paper-line);
  font-size: 13px;
  color: var(--text-muted);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}
footer.page-footer a { color: var(--text-muted); }
footer.page-footer a:hover { color: var(--accent-strong); }

.top-mobile-nav { display: none; }

@media (max-width: 720px) {
  .layout { grid-template-columns: 1fr; }
  .spine { display: none; }
  .top-mobile-nav {
    display: flex;
    position: sticky;
    top: 0;
    z-index: 5;
    align-items: center;
    justify-content: space-between;
    background: var(--ink);
    color: var(--paper);
    padding: 14px 18px;
  }
  .top-mobile-nav .brand { display: flex; align-items: center; gap: 10px; font-family: var(--font-display); font-weight: 600; }
  .top-mobile-nav .brand-dots { display: flex; gap: 4px; }
  .top-mobile-nav .brand-dots span { width: 5px; height: 5px; border-radius: 50%; background: var(--gold); }
  .top-mobile-nav nav { display: flex; gap: 16px; }
  .top-mobile-nav nav a { font-family: var(--font-mono); font-size: 11px; text-transform: uppercase; letter-spacing: .08em; color: var(--text-muted); text-decoration: none; }
  .top-mobile-nav nav a.active { color: var(--gold); }
  .content { padding: 40px 20px 72px; }
  .card-grid { grid-template-columns: 1fr; }
}