@import url('https://fonts.googleapis.com/css2?family=Inter:ital,wght@0,300;0,400;0,500;0,600;1,300&display=swap');

:root {
  --text:         #111111;
  --text-muted:   #666666;
  --bg:           #ffffff;
  --bg-subtle:    #f7f7f7;
  --border:       #e8e8e8;
  --accent:       #4a6fa5;
  --accent-light: #eef2f8;
}

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

html { font-size: 16px; }

body {
  font-family: 'Inter', system-ui, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

/* ── Navigation ─────────────────────────────────────────── */
nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 2.5rem;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 100;
}

.nav-logo {
  font-weight: 600;
  font-size: 1rem;
  letter-spacing: -0.02em;
  color: var(--text);
}

.nav-logo span {
  color: var(--accent);
}

.nav-links {
  display: flex;
  gap: 2.25rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.875rem;
  font-weight: 400;
  transition: color 0.15s ease;
}

.nav-links a:hover {
  color: var(--text);
}

.nav-links a.active {
  color: var(--accent);
  font-weight: 500;
}

/* ── Layout ──────────────────────────────────────────────── */
main {
  max-width: 960px;
  margin: 0 auto;
  padding: 3.5rem 2.5rem 5rem;
}

/* ── Hero ────────────────────────────────────────────────── */
.hero {
  padding: 4.5rem 0 3.5rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 3.5rem;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 600;
  letter-spacing: -0.045em;
  line-height: 1.05;
  margin-bottom: 1rem;
}

.hero .tagline {
  font-size: 1.15rem;
  color: var(--text-muted);
  font-weight: 300;
  font-style: italic;
  margin-bottom: 1.75rem;
}

.hero .intro {
  font-size: 0.975rem;
  color: var(--text-muted);
  max-width: 580px;
  line-height: 1.75;
}

/* ── Page header ─────────────────────────────────────────── */
.page-header {
  padding: 3rem 0 2rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 3rem;
}

.page-header h1 {
  font-size: 2rem;
  font-weight: 600;
  letter-spacing: -0.03em;
  margin-bottom: 0.5rem;
}

.page-header p {
  color: var(--text-muted);
  font-size: 0.925rem;
  max-width: 560px;
  line-height: 1.65;
}

/* ── Section label ───────────────────────────────────────── */
.section-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
  margin-bottom: 2rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--accent-light);
}

/* ── Chart blocks ────────────────────────────────────────── */
.chart-block {
  margin-bottom: 4rem;
}

.chart-block h3 {
  font-size: 0.975rem;
  font-weight: 500;
  margin-bottom: 0.35rem;
  letter-spacing: -0.01em;
}

.chart-block p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.875rem;
  line-height: 1.55;
  max-width: 620px;
}

.chart-block iframe {
  width: 100%;
  height: 520px;
  border: none;
  display: block;
  background: var(--bg-subtle);
}

/* ── About page ──────────────────────────────────────────── */
.about-section {
  margin-bottom: 3rem;
}

.about-section h2 {
  font-size: 1.05rem;
  font-weight: 500;
  margin-bottom: 0.875rem;
  letter-spacing: -0.01em;
}

.about-section p,
.about-section li {
  font-size: 0.925rem;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 0.75rem;
}

.about-section ul {
  padding-left: 1.25rem;
  margin-bottom: 0.75rem;
}

.about-section a {
  color: var(--accent);
  border-bottom: 1px solid var(--accent-light);
  transition: border-color 0.15s;
}

.about-section a:hover {
  border-color: var(--accent);
}

.signoff {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  font-size: 0.9rem;
  color: var(--text-muted);
  font-style: italic;
  line-height: 1.75;
}

/* ── Footer ──────────────────────────────────────────────── */
footer {
  max-width: 960px;
  margin: 0 auto;
  padding: 1.75rem 2.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.775rem;
  color: var(--text-muted);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 680px) {
  nav {
    padding: 1rem 1.25rem;
    flex-wrap: wrap;
    gap: 0.75rem;
  }

  .nav-links {
    gap: 1.5rem;
  }

  main {
    padding: 2rem 1.25rem 4rem;
  }

  .hero {
    padding: 2.5rem 0 2rem;
  }

  .hero h1 {
    font-size: 2.1rem;
  }

  .page-header {
    padding: 2rem 0 1.5rem;
  }

  .chart-block iframe {
    height: 420px;
  }

  footer {
    padding: 1.5rem 1.25rem;
    flex-direction: column;
    align-items: flex-start;
  }
}