:root {
  --navy: #0A1F3C;
  --navy-deep: #07162B;
  --blue: #2563EB;
  --blue-tint: rgba(37, 99, 235, 0.08);
  --blue-border: rgba(37, 99, 235, 0.25);
  --gray: #475569;
  --gray-light: #6B7A8C;
  --surface: #F8FAFC;
  --surface-alt: #F5F8FC;
  --border: #E2E8F0;
  --white: #FFFFFF;
  --blue-pale: #C7D9F2;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--navy);
  background: var(--white);
  line-height: 1.5;
}

h1, h2, h3 {
  font-weight: 700;
  line-height: 1.2;
}

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

/* Buttons */

.btn {
  display: inline-block;
  border-radius: 10px;
  font-weight: 600;
  font-size: 16px;
  padding: 15px 28px;
  transition: opacity 0.15s ease, transform 0.15s ease;
}

.btn:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--blue);
  color: var(--white);
}

.btn-secondary {
  background: var(--white);
  color: var(--navy);
  border: 1px solid #CFD8E5;
}

.btn-sm {
  font-size: 15px;
  padding: 11px 22px;
  border-radius: 8px;
}

.btn-lg {
  font-size: 17px;
  padding: 16px 32px;
}

/* Nav */

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 80px;
  background: var(--white);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-mark {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--blue);
  position: relative;
}

.logo-mark::after {
  content: "";
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--white);
  left: 8px;
  top: 8px;
}

.logo-word {
  font-size: 22px;
  font-weight: 700;
  color: var(--navy);
}

.nav-links {
  display: flex;
  gap: 36px;
}

.nav-links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--gray);
  transition: color 0.15s ease;
}

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

/* Hero */

.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 28px;
  padding: 88px 160px 72px;
  background: linear-gradient(180deg, var(--white) 0%, #EFF4FB 100%);
  text-align: center;
}

.eyebrow {
  display: inline-block;
  padding: 7px 14px;
  border-radius: 100px;
  background: var(--blue-tint);
  border: 1px solid var(--blue-border);
  color: var(--blue);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.hero h1 {
  font-size: 56px;
  line-height: 1.12;
}

.hero-sub {
  max-width: 720px;
  font-size: 19px;
  line-height: 1.55;
  color: var(--gray);
}

.hero-ctas {
  display: flex;
  gap: 16px;
  align-items: center;
}

/* Flow card */

.flow-card {
  display: flex;
  align-items: center;
  gap: 36px;
  margin-top: 20px;
  padding: 40px 48px;
  border-radius: 20px;
  background: var(--white);
  border: 1px solid var(--border);
  box-shadow: 0 12px 32px -8px rgba(10, 31, 61, 0.08);
  text-align: left;
}

.flow-col {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.mini-card {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 14px 18px;
  border-radius: 12px;
  background: var(--surface);
  border: 1px solid var(--border);
}

.mini-card strong {
  font-size: 15px;
  font-weight: 600;
  color: var(--navy);
}

.mini-card span {
  font-size: 12.5px;
  color: var(--gray-light);
}

.flow-arrow {
  flex-shrink: 0;
}

.engine-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 24px 28px;
  border-radius: 14px;
  background: var(--navy);
  color: var(--white);
}

.engine-card strong {
  font-size: 18px;
  font-weight: 600;
}

.engine-card ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
  text-align: center;
}

.engine-card li {
  font-size: 13px;
  color: var(--blue-pale);
}

.engine-card li::before {
  content: "•  ";
}

/* Sections */

.section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 48px;
  padding: 96px 160px;
  background: var(--white);
}

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

.section-header {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  text-align: center;
}

.section-header h2 {
  font-size: 38px;
}

.section-header p {
  font-size: 17px;
  line-height: 1.5;
  color: var(--gray);
}

/* How it works */

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  max-width: 1144px;
  width: 100%;
}

.step-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 28px 24px;
  border-radius: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
}

.step-num {
  font-size: 15px;
  font-weight: 700;
  color: var(--blue);
}

.step-card h3 {
  font-size: 19px;
  font-weight: 600;
}

.step-card p {
  font-size: 14.5px;
  line-height: 1.5;
  color: var(--gray);
}

/* Who it's for */

.audience {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 1120px;
  width: 100%;
}

.audience-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 16px;
  padding: 32px 28px;
  border-radius: 16px;
  background: var(--white);
  border: 1px solid var(--border);
  box-shadow: 0 6px 18px -4px rgba(10, 31, 61, 0.05);
}

.icon-box {
  display: inline-flex;
  padding: 12px;
  border-radius: 12px;
  background: var(--blue-tint);
}

.audience-card h3 {
  font-size: 21px;
  font-weight: 600;
}

.audience-card p {
  font-size: 15px;
  line-height: 1.55;
  color: var(--gray);
}

/* Why Neutrino */

.features {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: 1120px;
  width: 100%;
}

.feature-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 32px;
  border-radius: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
}

.feature-card h3 {
  font-size: 20px;
  font-weight: 600;
}

.feature-card p {
  font-size: 15px;
  line-height: 1.55;
  color: var(--gray);
}

/* CTA */

.cta {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 28px;
  padding: 88px 160px;
  background: var(--navy);
  text-align: center;
}

.cta h2 {
  font-size: 40px;
  color: var(--white);
}

.cta p {
  max-width: 640px;
  font-size: 17px;
  line-height: 1.5;
  color: var(--blue-pale);
}

/* Footer */

.footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 32px 80px;
  background: var(--navy-deep);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.footer .logo-word {
  font-size: 17px;
  color: var(--white);
}

.footer-copy {
  font-size: 13.5px;
  color: #8C9EB8;
}

.footer-links {
  display: flex;
  gap: 28px;
}

.footer-links a {
  font-size: 13.5px;
  font-weight: 500;
  color: #B3C4D9;
  transition: color 0.15s ease;
}

.footer-links a:hover {
  color: var(--white);
}

/* Responsive */

@media (max-width: 1200px) {
  .hero,
  .section,
  .cta {
    padding-left: 48px;
    padding-right: 48px;
  }

  .steps {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 900px) {
  .nav {
    padding: 20px 24px;
  }

  .nav-links {
    display: none;
  }

  .hero h1 {
    font-size: 38px;
  }

  .hero h1 br,
  .cta h2 br {
    display: none;
  }

  .flow-card {
    flex-direction: column;
    gap: 20px;
  }

  .flow-arrow {
    transform: rotate(90deg);
  }

  .audience {
    grid-template-columns: 1fr;
  }

  .features {
    grid-template-columns: 1fr;
  }

  .section-header h2 {
    font-size: 30px;
  }

  .cta h2 {
    font-size: 32px;
  }

  .footer {
    flex-direction: column;
    gap: 16px;
    padding: 28px 24px;
  }
}

@media (max-width: 600px) {
  .hero,
  .section,
  .cta {
    padding-left: 20px;
    padding-right: 20px;
  }

  .steps {
    grid-template-columns: 1fr;
  }

  .hero-ctas {
    flex-direction: column;
    width: 100%;
  }

  .hero-ctas .btn {
    width: 100%;
  }
}