:root {
  --bg: #FAF8F1;
  --fg: #1C1C1E;
  --fg-muted: #6B6B6B;
  --accent: #3D5A47;
  --accent-light: #EBF0EC;
  --card-bg: #FFFFFF;
  --border: #E4E1D8;

  --font-display: 'Playfair Display', Georgia, serif;
  --font-body: 'Source Serif 4', Georgia, serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ─── Navigation ─── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 20px 40px;
  display: flex;
  align-items: center;
}
.nav-logo {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.02em;
}

/* ─── Hero ─── */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 40px 80px;
}
.hero-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}
.hero-eyebrow {
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 20px;
}
.hero-headline {
  font-family: var(--font-display);
  font-size: clamp(42px, 5vw, 72px);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--fg);
  margin-bottom: 28px;
}
.hero-sub {
  font-size: 19px;
  color: var(--fg-muted);
  max-width: 400px;
  line-height: 1.65;
}

/* Hero Visual — Exchange Diagram */
.hero-visual {
  display: flex;
  align-items: center;
  gap: 24px;
  justify-content: flex-end;
}
.diary-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px 22px;
  width: 160px;
  box-shadow: 0 2px 16px rgba(0,0,0,0.06);
}
.diary-label {
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 12px;
}
.diary-line {
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  margin-bottom: 8px;
}
.diary-line--short { width: 65%; }
.diary-card--send {
  background: var(--accent);
  border-color: var(--accent);
}
.diary-card--send .diary-label { color: rgba(255,255,255,0.7); }
.diary-card--send .diary-line { background: rgba(255,255,255,0.25); }
.diary-pile {
  display: flex;
  flex-direction: column;
  gap: -20px;
}
.diary-card--recv {
  width: 148px;
  margin-bottom: -30px;
}
.diary-card--tilt1 { transform: rotate(-3deg); }
.diary-card--tilt2 { transform: rotate(2deg) translateY(-24px); }
.diary-card--tilt3 { transform: rotate(-1.5deg) translateY(-48px); }
.exchange-arrow {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  color: var(--accent);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 600;
  writing-mode: vertical-rl;
  margin: 0 4px;
}

/* ─── Mechanics ─── */
.mechanics {
  background: var(--card-bg);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 100px 40px;
}
.mechanics-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.mechanics-heading {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 60px;
  letter-spacing: -0.01em;
}
.mechanics-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px 80px;
}
.mechanic {}
.mechanic-num {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 400;
  color: var(--fg-muted);
  margin-bottom: 12px;
  font-style: italic;
}
.mechanic-name {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  color: var(--fg);
  margin-bottom: 10px;
}
.mechanic-desc {
  font-size: 16px;
  color: var(--fg-muted);
  line-height: 1.65;
}

/* ─── Exchange / Quote ─── */
.exchange {
  padding: 100px 40px;
}
.exchange-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.exchange-quote {
  text-align: center;
  margin-bottom: 80px;
}
.exchange-quote blockquote {
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 34px);
  font-style: italic;
  color: var(--fg);
  line-height: 1.4;
  max-width: 700px;
  margin: 0 auto 20px;
}
.exchange-quote cite {
  font-size: 14px;
  color: var(--fg-muted);
  font-style: normal;
}

/* Exchange Diagram */
.exchange-diagram {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  flex-wrap: wrap;
}
.exchange-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 0 40px;
}
.exchange-icon {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: var(--accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
}
.poplar-tree { color: var(--accent); }
.exchange-node span {
  font-size: 14px;
  color: var(--fg-muted);
  text-align: center;
}
.exchange-connector {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
.connector-line {
  width: 80px;
  height: 2px;
  background: var(--border);
  position: relative;
}
.connector-badge {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-light);
  padding: 4px 10px;
  border-radius: 20px;
}

/* ─── Manifesto ─── */
.manifesto {
  background: var(--accent);
  color: #fff;
  padding: 100px 40px;
}
.manifesto-inner {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}
.manifesto-text {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 52px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 28px;
}
.manifesto-text--secondary {
  font-size: 18px;
  font-weight: 400;
  font-style: italic;
  opacity: 0.85;
  font-family: var(--font-display);
  line-height: 1.5;
}

/* ─── Closing ─── */
.closing {
  padding: 100px 40px;
}
.closing-inner {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}
.closing-line {
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 400;
  color: var(--fg);
  line-height: 1.45;
  margin-bottom: 20px;
}
.closing-line--small {
  font-size: 17px;
  color: var(--fg-muted);
}

/* ─── Footer ─── */
.footer {
  border-top: 1px solid var(--border);
  padding: 40px;
}
.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.footer-logo {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--accent);
}
.footer-tagline {
  font-size: 13px;
  color: var(--fg-muted);
  margin-top: 4px;
}
.footer-links {
  display: flex;
  gap: 28px;
}
.footer-links a {
  font-size: 14px;
  color: var(--fg-muted);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-links a:hover { color: var(--accent); }

/* ─── Mobile ─── */
@media (max-width: 768px) {
  .nav { padding: 16px 24px; }
  .hero { padding: 100px 24px 60px; }
  .hero-inner { grid-template-columns: 1fr; gap: 48px; }
  .hero-visual { justify-content: flex-start; }
  .hero-sub { max-width: 100%; }
  .mechanics { padding: 72px 24px; }
  .mechanics-grid { grid-template-columns: 1fr; gap: 36px; }
  .exchange { padding: 72px 24px; }
  .exchange-diagram { flex-direction: column; gap: 16px; }
  .exchange-connector { transform: rotate(90deg); }
  .manifesto { padding: 72px 24px; }
  .closing { padding: 72px 24px; }
  .footer { padding: 32px 24px; }
  .footer-inner { flex-direction: column; gap: 20px; align-items: flex-start; }
  .diary-card { width: 130px; }
  .diary-card--recv { width: 120px; }
}