:root {
  --ink: #1c2430;
  --ink-soft: #44505f;
  --paper: #faf9f5;
  --paper-alt: #f0efe6;
  --brand: #0f6656;
  --brand-dark: #0a4a3f;
  --brand-light: #eaf6f1;
  --border: #e2e0d4;
  --max: 760px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.55;
}

.wrap {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

h1, h2, h3 {
  line-height: 1.2;
  font-weight: 700;
  color: var(--ink);
}

h2 {
  font-size: 1.7rem;
  margin-bottom: 1rem;
}

h3 {
  font-size: 1.15rem;
  margin: 0.75rem 0 0.4rem;
}

p {
  color: var(--ink-soft);
  margin: 0 0 1rem;
}

a { color: var(--brand-dark); }

/* Header */

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--paper);
  position: sticky;
  top: 0;
  z-index: 10;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  padding-bottom: 14px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.brand-mark {
  display: block;
  border-radius: 8px;
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  color: var(--brand-dark);
}

.nav-cta {
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--brand-dark);
  border: 1px solid var(--brand-dark);
  padding: 8px 16px;
  border-radius: 999px;
  white-space: nowrap;
}

.nav-cta:hover {
  background: var(--brand-dark);
  color: var(--brand-light);
}

/* Hero */

.hero {
  background: linear-gradient(180deg, var(--brand-dark), var(--brand));
  color: var(--brand-light);
  padding: 76px 0 84px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  align-items: center;
  gap: 32px;
}

.hero-copy { text-align: left; }

.hero h1 {
  color: #ffffff;
  font-size: clamp(2rem, 5vw, 2.9rem);
  margin: 0 0 20px;
  letter-spacing: -0.02em;
}

.hero-sub {
  color: var(--brand-light);
  font-size: 1.1rem;
  max-width: 480px;
  margin: 0 0 32px;
}

.hero-visual svg {
  width: 100%;
  height: auto;
  max-width: 420px;
  display: block;
  margin: 0 auto;
}

.nfc-wave path {
  animation: nfc-pulse 2.2s ease-in-out infinite;
}

.nfc-wave path:nth-child(2) { animation-delay: 0.2s; }
.nfc-wave path:nth-child(3) { animation-delay: 0.4s; }

@keyframes nfc-pulse {
  0%, 100% { opacity: 0.25; }
  50% { opacity: 0.9; }
}

@media (max-width: 760px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-copy { text-align: center; }
  .hero-sub { margin-left: auto; margin-right: auto; }
  .hero-visual { max-width: 320px; margin: 0 auto; }
}

/* Buttons */

.btn {
  display: inline-block;
  text-decoration: none;
  font-weight: 700;
  font-size: 1rem;
  padding: 14px 30px;
  border-radius: 999px;
  transition: transform 0.1s ease;
}

.btn:hover { transform: translateY(-1px); }

.btn-primary {
  background: #ffffff;
  color: var(--brand-dark);
}

.btn-primary:hover {
  background: var(--brand-light);
}

/* Sections */

.section {
  padding: 64px 0;
}

.section.problem,
.section.how,
.section.why {
  background: var(--paper-alt);
}

.section p:last-child { margin-bottom: 0; }

/* Eco section (dark, like the hero, for visual weight) */

.section.eco {
  background: linear-gradient(180deg, var(--brand-dark), var(--brand));
}

.section.eco h2 {
  color: #ffffff;
}

.section.eco p {
  color: var(--brand-light);
}

.eco-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--brand-light);
  background: rgba(255, 255, 255, 0.14);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 18px;
}

.stat-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  margin: 8px 0 32px;
}

.stat-value {
  font-size: clamp(2.4rem, 6vw, 3rem);
  font-weight: 700;
  color: #ffffff;
  line-height: 1;
  margin-bottom: 8px;
}

.stat-label {
  color: var(--brand-light);
  font-size: 0.92rem;
  max-width: 320px;
}

.section.eco .impact-tile {
  background: #ffffff;
  border-color: rgba(255, 255, 255, 0.35);
}

.section.eco .impact-tile h3 {
  color: #1c2430;
}

.section.eco .impact-tile p {
  color: #44505f;
}

.section.eco .step-icon {
  color: var(--brand);
}

@media (max-width: 640px) {
  .stat-row {
    grid-template-columns: 1fr;
  }
}

.flow-diagram {
  margin-top: 28px;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
}

.flow-diagram svg {
  width: 100%;
  height: auto;
  display: block;
}

.layer-diagram {
  margin-top: 28px;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
}

.layer-diagram svg {
  width: 100%;
  height: auto;
  display: block;
}

.diagram-box { stroke: #9aa5b1; }
.diagram-box-fill { fill: #efeee3; stroke: #cfcdbb; }
.diagram-label { fill: #44505f; }
.diagram-sublabel { fill: #6b7684; }
.diagram-arrow { stroke: #9aa5b1; }
.diagram-arrowhead { fill: #9aa5b1; }

.pilot-note {
  margin-top: 1.5rem;
  padding: 16px 20px;
  background: var(--brand-light);
  border-left: 4px solid var(--brand);
  border-radius: 4px;
  color: var(--ink);
  font-size: 0.95rem;
}

/* How it works steps / impact tiles (same card treatment) */

.steps,
.impact-tiles {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-top: 24px;
}

.step,
.impact-tile {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 28px 22px 24px;
}

.step-icon {
  width: 48px;
  height: 48px;
  color: var(--brand);
}

.step-icon svg {
  width: 100%;
  height: 100%;
  display: block;
}

.step-num {
  position: absolute;
  top: -14px;
  right: 18px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--brand);
  color: #fff;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
}

.impact-tiles--two {
  grid-template-columns: repeat(2, 1fr);
  max-width: 600px;
}

@media (max-width: 640px) {
  .steps,
  .impact-tiles {
    grid-template-columns: 1fr;
    gap: 28px;
  }
}

/* Pilot / contact */

.section.pilot {
  text-align: center;
}

.section.pilot .btn-primary {
  background: var(--brand);
  color: #fff;
}

.section.pilot .btn-primary:hover {
  background: var(--brand-dark);
}

/* Footer */

.site-footer {
  background: var(--ink);
  color: #b9c2cd;
  padding: 24px 0;
  font-size: 0.85rem;
}

.site-footer .wrap {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #eef1f4;
    --ink-soft: #b7c0cb;
    --paper: #12181d;
    --paper-alt: #1a2129;
    --border: #2a323b;
    --brand-light: #d9efe7;
  }

  .btn-primary {
    background: #182420;
    color: var(--brand-light);
  }

  .btn-primary:hover {
    background: #223832;
  }

  .site-header {
    background: var(--paper);
  }

  .pilot-note {
    background: #16302a;
    color: var(--ink);
  }

  .diagram-box { stroke: #495159; }
  .diagram-box-fill { fill: #1c242c; stroke: #333c46; }
  .diagram-label { fill: #dfe4ea; }
  .diagram-sublabel { fill: #9aa5b1; }
  .diagram-arrow { stroke: #6b7684; }
  .diagram-arrowhead { fill: #6b7684; }
}