:root {
  --primary: #0d4f5c;
  --primary-light: #15697a;
  --primary-dark: #083840;
  --accent: #2a9d8f;
  --text: #1a2332;
  --muted: #5c6b7a;
  --bg: #f4f7f9;
  --white: #ffffff;
  --border: #dde4ea;
  --radius: 12px;
  --shadow: 0 12px 40px rgba(13, 79, 92, 0.08);
  --max: 1120px;
}

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

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}

img { max-width: 100%; height: auto; }

a { color: var(--primary-light); }
a:hover { color: var(--primary-dark); }

.container {
  width: min(var(--max), calc(100% - 2rem));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  min-height: 4rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  text-decoration: none;
  margin-right: auto;
}

.logo-mark {
  display: inline-grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  font-size: 0.95rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem 1rem;
  flex-wrap: wrap;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 500;
  padding: 0.35rem 0;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
}

.header-cta { display: none; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  background: var(--primary);
  color: white !important;
  padding: 0.85rem 1.4rem;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 600;
  border: 2px solid transparent;
  cursor: pointer;
  font-size: 0.95rem;
  transition: background 0.15s, transform 0.15s;
}

.btn:hover { background: var(--primary-dark); transform: translateY(-1px); }

.btn-outline {
  background: transparent;
  color: var(--primary) !important;
  border-color: var(--primary);
}

.btn-outline:hover { background: var(--primary); color: white !important; }

.btn-sm { padding: 0.55rem 1rem; font-size: 0.85rem; }

.btn-accent { background: var(--accent); }
.btn-accent:hover { background: #238b7f; }

.hero {
  padding: 4.5rem 0 3.5rem;
  background: linear-gradient(160deg, #e8f3f5 0%, var(--bg) 55%, #eef6f4 100%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 2.5rem;
  align-items: center;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent);
  margin: 0 0 0.75rem;
}

.hero h1 {
  font-size: clamp(2rem, 4.5vw, 3rem);
  line-height: 1.12;
  margin: 0 0 1rem;
  color: var(--primary-dark);
}

.lead {
  font-size: 1.12rem;
  color: var(--muted);
  margin: 0 0 1.5rem;
  max-width: 52ch;
}

.hero-actions { display: flex; flex-wrap: wrap; gap: 0.75rem; }

.hero-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.hero-card h2 {
  margin: 0 0 0.75rem;
  font-size: 1.15rem;
  color: var(--primary);
}

.hero-stat {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.65rem 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.92rem;
}

.hero-stat:last-child { border-bottom: none; }

.hero-stat strong { color: var(--primary-dark); }

.section { padding: 4rem 0; }
.section-alt { background: var(--white); }

.section-header {
  max-width: 680px;
  margin-bottom: 2.5rem;
}

.section-header h2 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  color: var(--primary-dark);
}

.section-header p { margin: 0; color: var(--muted); }

.diagram-section .section-header {
  max-width: 720px;
}

.diagram-figure {
  margin: 0;
  padding: 1rem;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow-x: auto;
}

.diagram-figure img {
  display: block;
  width: 100%;
  min-width: 640px;
  height: auto;
  margin-inline: auto;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.5rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.5rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1.25rem;
}

.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  color: var(--primary);
}

.card p { margin: 0; color: var(--muted); font-size: 0.95rem; }

.card-icon {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 10px;
  background: #e6f3f5;
  color: var(--primary);
  display: grid;
  place-items: center;
  font-weight: 700;
  margin-bottom: 1rem;
}

.featured-card {
  border-color: var(--accent);
  background: linear-gradient(135deg, #f0faf8, var(--white));
}

.stat-block {
  text-align: center;
  padding: 1.5rem 1rem;
}

.stat-number {
  display: block;
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  font-weight: 800;
  color: var(--primary);
  line-height: 1.1;
}

.stat-label {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.88rem;
  color: var(--muted);
}

.citation-list {
  margin: 2rem 0 0;
  padding: 0;
  list-style: none;
}

.citation-list li {
  padding: 1rem 0;
  border-top: 1px solid var(--border);
  font-size: 0.88rem;
  color: var(--muted);
}

.citation-list a { word-break: break-word; }

.stat-callout {
  background: #edf6f7;
  border-left: 4px solid var(--accent);
  padding: 1.25rem 1.5rem;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin: 1.5rem 0;
}

.stat-callout p { margin: 0; }

.stat-callout strong { color: var(--primary-dark); }

.steps {
  counter-reset: step;
  display: grid;
  gap: 1.25rem;
}

.step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.25rem;
  align-items: start;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.step::before {
  counter-increment: step;
  content: counter(step);
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  background: var(--primary);
  color: white;
  display: grid;
  place-items: center;
  font-weight: 700;
}

.cta-band {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: white;
  padding: 3rem 0;
  text-align: center;
}

.cta-band h2 { margin: 0 0 0.75rem; color: white; }
.cta-band p { margin: 0 auto 1.5rem; max-width: 520px; opacity: 0.9; }
.cta-band .btn-outline { border-color: white; color: white !important; }
.cta-band .btn-outline:hover { background: white; color: var(--primary) !important; }

.page-hero {
  padding: 3rem 0 2rem;
  background: var(--white);
  border-bottom: 1px solid var(--border);
}

.page-hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.8rem, 3.5vw, 2.5rem);
  color: var(--primary-dark);
}

.page-hero p { margin: 0; color: var(--muted); max-width: 65ch; }

.prose { max-width: 72ch; }
.prose h2 { color: var(--primary-dark); margin-top: 2rem; }
.prose h3 { color: var(--primary); margin-top: 1.5rem; font-size: 1.15rem; }
.prose p, .prose li { color: var(--muted); }

.notice-box {
  background: #fff8f0;
  border: 1px solid #e8d4b8;
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  max-width: 72ch;
}

.notice-box p {
  margin: 0;
  font-size: 0.92rem;
  color: var(--text);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  margin: 1.5rem 0;
}

.comparison-table th,
.comparison-table td {
  border: 1px solid var(--border);
  padding: 0.85rem 1rem;
  text-align: left;
}

.comparison-table th {
  background: #edf4f6;
  color: var(--primary-dark);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: start;
}

.contact-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
}

.contact-form {
  display: grid;
  gap: 1rem;
}

.contact-form label {
  display: grid;
  gap: 0.35rem;
  font-weight: 600;
  font-size: 0.9rem;
}

.contact-form input,
.contact-form select,
.contact-form textarea {
  font: inherit;
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--white);
}

.contact-form textarea { min-height: 120px; resize: vertical; }

.site-footer {
  background: var(--primary-dark);
  color: rgba(255, 255, 255, 0.85);
  padding: 3rem 0 0;
  margin-top: 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 2rem;
  padding-bottom: 2rem;
}

.footer-brand { margin: 0 0 0.5rem; font-size: 1.1rem; }
.footer-tagline { margin: 0; opacity: 0.75; font-size: 0.92rem; }
.footer-heading { font-weight: 700; margin: 0 0 0.75rem; color: white; }

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-links li { margin-bottom: 0.45rem; }
.footer-links a { color: rgba(255, 255, 255, 0.8); text-decoration: none; }
.footer-links a:hover { color: white; }

.footer-address {
  font-size: 0.88rem;
  line-height: 1.5;
  opacity: 0.85;
  margin-top: 0.35rem;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding: 1rem 0 1.5rem;
  font-size: 0.85rem;
  opacity: 0.7;
}

@media (min-width: 900px) {
  .header-cta { display: inline-flex; }
}

@media (max-width: 899px) {
  .nav-toggle { display: flex; }
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    padding: 1rem;
    box-shadow: var(--shadow);
  }
  .nav-links.is-open { display: flex; }
  .site-header .container { position: relative; }
  .hero-grid, .grid-2, .grid-3, .grid-4, .contact-grid, .footer-grid {
    grid-template-columns: 1fr;
  }
}