:root {
  --brand-50: #f1faec;
  --brand-100: #dff3d3;
  --brand-200: #c0e7ac;
  --brand-300: #98d67c;
  --brand-400: #72c052;
  --brand-500: #4f9c31;
  --brand-600: #3c7d25;
  --brand-700: #2f611f;
  --brand-800: #264d1c;
  --brand-900: #20401b;
  --ink-900: #0d1a12;

  --neutral-50: #fafafa;
  --neutral-100: #f5f5f5;
  --neutral-200: #e5e5e5;
  --neutral-400: #a3a3a3;
  --neutral-500: #737373;
  --neutral-600: #525252;
  --neutral-900: #171717;

  --max-width: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--ink-900);
  background: #ffffff;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
}

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

/* --- Header --- */

header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--neutral-200);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav-logo img {
  height: 40px;
  width: auto;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a.nav-link {
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--neutral-600);
  text-decoration: none;
}

.nav-links a.nav-link:hover {
  background: var(--neutral-100);
  color: var(--ink-900);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 600;
  padding: 10px 20px;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: background-color 0.15s ease, box-shadow 0.15s ease;
}

.btn-primary {
  background: var(--brand-600);
  color: #ffffff;
}

.btn-primary:hover {
  background: var(--brand-700);
}

.btn-secondary {
  background: #ffffff;
  color: var(--ink-900);
  border: 1px solid var(--neutral-200);
}

.btn-secondary:hover {
  border-color: var(--brand-400);
  color: var(--brand-700);
}

/* --- Hero --- */

.hero {
  background: linear-gradient(180deg, var(--brand-50) 0%, #ffffff 65%);
  padding: 88px 0 96px;
  text-align: center;
}

.hero .eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--brand-700);
  background: var(--brand-100);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: 44px;
  line-height: 1.15;
  margin: 0 0 20px;
  letter-spacing: -0.01em;
}

.hero p.lead {
  font-size: 18px;
  color: var(--neutral-600);
  max-width: 620px;
  margin: 0 auto 36px;
  line-height: 1.6;
}

.hero .cta-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

/* --- Sections --- */

section {
  padding: 88px 0;
}

section.alt {
  background: var(--neutral-50);
}

.section-head {
  text-align: center;
  max-width: 620px;
  margin: 0 auto 56px;
}

.section-head .kicker {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--brand-600);
  margin-bottom: 10px;
}

.section-head h2 {
  font-size: 30px;
  margin: 0 0 12px;
  letter-spacing: -0.01em;
}

.section-head p {
  color: var(--neutral-600);
  font-size: 16px;
  line-height: 1.6;
  margin: 0;
}

/* --- Feature grid --- */

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.card {
  background: #ffffff;
  border: 1px solid var(--neutral-200);
  border-radius: 16px;
  padding: 28px;
}

.card .icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--brand-100);
  color: var(--brand-700);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
}

.card h3 {
  font-size: 17px;
  margin: 0 0 8px;
}

.card p {
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--neutral-600);
  margin: 0;
}

/* --- Chart card --- */

.chart-card {
  background: #ffffff;
  border: 1px solid var(--neutral-200);
  border-radius: 16px;
  padding: 28px;
  max-width: 760px;
  margin: 0 auto;
}

.chart-card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.chart-card-head h3 {
  font-size: 17px;
  margin: 0 0 2px;
}

.chart-sub {
  font-size: 13px;
  color: var(--neutral-500);
}

.chip-muted {
  background: var(--neutral-100);
  color: var(--neutral-600);
  border: none;
  font-size: 12.5px;
}

.chip-muted .dot {
  background: var(--neutral-400);
}

.chart-wrap {
  position: relative;
}

.chart-wrap svg {
  width: 100%;
  height: auto;
  display: block;
  cursor: crosshair;
}

.chart-tooltip {
  position: absolute;
  background: var(--ink-900);
  color: #ffffff;
  font-size: 12.5px;
  font-weight: 600;
  padding: 5px 10px;
  border-radius: 8px;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.1s ease;
  white-space: nowrap;
}

/* --- Steps --- */

.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 32px;
  counter-reset: step;
}

.step {
  position: relative;
  padding-left: 52px;
}

.step .num {
  position: absolute;
  left: 0;
  top: 0;
  width: 36px;
  height: 36px;
  border-radius: 999px;
  background: var(--brand-600);
  color: #fff;
  font-weight: 700;
  font-size: 15px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.step h3 {
  font-size: 16px;
  margin: 4px 0 8px;
}

.step p {
  font-size: 14.5px;
  color: var(--neutral-600);
  line-height: 1.6;
  margin: 0;
}

/* --- Sensor type chips --- */

.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #ffffff;
  border: 1px solid var(--neutral-200);
  border-radius: 999px;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 500;
}

.chip .dot {
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: var(--brand-500);
}

/* --- Contact --- */

.contact-card {
  background: linear-gradient(135deg, var(--brand-700), var(--brand-900));
  border-radius: 24px;
  padding: 56px;
  text-align: center;
  color: #ffffff;
}

.contact-card h2 {
  font-size: 28px;
  margin: 0 0 12px;
}

.contact-card p {
  color: var(--brand-100);
  font-size: 16px;
  max-width: 480px;
  margin: 0 auto 28px;
  line-height: 1.6;
}

.contact-card .email-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: #ffffff;
  color: var(--brand-800);
  font-weight: 700;
  font-size: 17px;
  padding: 14px 28px;
  border-radius: 12px;
  text-decoration: none;
}

.contact-card .email-link:hover {
  background: var(--brand-50);
}

/* --- Footer --- */

footer {
  border-top: 1px solid var(--neutral-200);
  padding: 40px 0;
}

.footer-row {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 16px;
}

.footer-row .footer-logo {
  justify-self: start;
}

.footer-row .powered-by {
  justify-self: center;
}

.footer-row .copyright {
  justify-self: end;
  text-align: right;
}

@media (max-width: 640px) {
  .footer-row {
    grid-template-columns: 1fr;
    justify-items: center;
    text-align: center;
  }
  .footer-row .footer-logo,
  .footer-row .powered-by,
  .footer-row .copyright {
    justify-self: center;
    text-align: center;
  }
}

.footer-row img.footer-logo {
  height: 28px;
  width: auto;
}

.powered-by {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--ink-900);
  border-radius: 999px;
  padding: 8px 16px;
}

.powered-by span {
  font-size: 12px;
  color: var(--neutral-400);
}

.powered-by img {
  height: 20px;
  width: auto;
}

.copyright {
  font-size: 13px;
  color: var(--neutral-500);
}

.legal-row {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--neutral-200);
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 6px;
  font-size: 12px;
  color: var(--neutral-500);
  text-align: center;
}

.legal-row .legal-sep {
  color: var(--neutral-200);
}

@media (max-width: 640px) {
  .legal-row .legal-sep {
    display: none;
  }
  .legal-row {
    flex-direction: column;
    gap: 2px;
  }
  .hero h1 {
    font-size: 32px;
  }
  .hero p.lead {
    font-size: 16px;
  }
  .contact-card {
    padding: 36px 24px;
  }
  .nav-links a.nav-link {
    display: none;
  }
}