:root {
  /* Single source of truth for pages that offset content below the fixed site header. */
  --site-header-height: 72px;
  --ink: #03070d;
  --blue: #2563eb;
  --cyan: #00d4ff;
  --paper: #ffffff;
  --gray: #a1a1aa;
  --line: rgba(255, 255, 255, 0.2);
  --soft: #f4f6fa;
  --text: #151515;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--site-header-height) + 12px);
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: Inter, Arial, sans-serif;
}

a {
  color: inherit;
}

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  height: var(--site-header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 36px;
  background: rgba(3, 7, 13, 0.92);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  text-decoration: none;
  color: var(--paper);
}

.brand-mark,
.signal-ring {
  position: relative;
  width: 42px;
  height: 42px;
  border: 2px solid var(--paper);
  border-radius: 50%;
}

.brand-mark::before,
.brand-mark::after,
.signal-ring::before,
.signal-ring::after {
  content: "";
  position: absolute;
  border: 2px solid var(--paper);
  border-radius: 50%;
  inset: 4px;
}

.brand-mark::after,
.signal-ring::after {
  inset: -6px;
  border-right-color: transparent;
  border-bottom-color: transparent;
}

.brand-name {
  color: var(--paper);
  font-size: 30px;
  font-weight: 400;
}

.top-nav {
  display: flex;
  align-items: center;
  gap: 22px;
}

.top-nav a {
  color: rgba(255, 255, 255, 0.82);
  text-decoration: none;
  font-size: 14px;
}

.top-nav a:hover {
  color: var(--cyan);
}

.hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--ink);
}

main#top {
  padding-top: var(--site-header-height);
}

.hero-image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.38;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: rgba(3, 7, 13, 0.58);
}

.hero-copy {
  position: relative;
  z-index: 2;
  max-width: 850px;
  padding: 132px 36px 72px;
  color: var(--paper);
}

.eyebrow,
.section-kicker {
  color: var(--cyan);
  font-weight: 700;
  font-size: 13px;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 780px;
  margin-bottom: 20px;
  font-size: 64px;
  line-height: 1.02;
  font-weight: 650;
}

h2 {
  max-width: 780px;
  margin-bottom: 16px;
  font-size: 38px;
  line-height: 1.14;
  font-weight: 650;
}

h3 {
  margin-bottom: 10px;
  font-size: 20px;
}

p {
  max-width: 760px;
  color: #3b3b42;
  font-size: 17px;
  line-height: 1.62;
}

.hero-copy p {
  color: rgba(255, 255, 255, 0.86);
  font-size: 19px;
}

.hero-actions,
.download-box {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 700;
}

.button.primary {
  background: var(--blue);
  color: var(--paper);
}

.button.secondary {
  border: 1px solid rgba(255, 255, 255, 0.62);
  color: var(--paper);
}

.section,
.band {
  padding: 86px 36px;
}

.section {
  background: var(--paper);
}

#fixie {
  min-height: calc(100vh - 72px);
  padding-top: 48px;
  padding-bottom: 40px;
  scroll-margin-top: 72px;
}

#fixie h2 {
  max-width: none;
  margin-bottom: 10px;
  font-size: 32px;
  line-height: 1.12;
}

#fixie .lead {
  max-width: 1120px;
  margin-bottom: 0;
  font-size: 17px;
  line-height: 1.45;
}

#fixie .guide-link {
  display: inline-block;
  margin-left: 8px;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(37, 99, 235, 0.10);
  color: var(--blue);
  font-weight: 700;
  text-decoration: none;
  box-shadow: inset 0 0 0 1px rgba(37, 99, 235, 0.18);
}

#fixie .guide-link:hover {
  background: rgba(37, 99, 235, 0.16);
  color: #1747b7;
}

#fixie .feature-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-top: 22px;
}

#fixie .feature {
  min-height: 0;
  padding: 18px;
}

#fixie .feature h3 {
  margin-bottom: 8px;
  font-size: 18px;
}

#fixie .feature p {
  font-size: 15.5px;
  line-height: 1.6;
}

.lead {
  font-size: 19px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-top: 30px;
}

.feature {
  min-height: 210px;
  padding: 24px;
  border: 1px solid #e3e5eb;
  border-radius: 8px;
  background: var(--paper);
}

.feature p {
  font-size: 15px;
}

.band {
  display: grid;
  grid-template-columns: minmax(0, 0.88fr) minmax(360px, 1.12fr);
  gap: 34px;
  align-items: center;
  background: var(--ink);
  color: var(--paper);
}

.band p {
  color: rgba(255, 255, 255, 0.78);
}

.signal-panel {
  display: grid;
  grid-template-columns: 170px minmax(0, 1fr);
  gap: 28px;
  align-items: center;
  padding: 34px;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.signal-ring {
  width: 136px;
  height: 136px;
}

.signal-ring::before {
  inset: 9px;
}

.signal-ring::after {
  inset: -12px;
  border-color: var(--blue);
  border-right-color: transparent;
  border-bottom-color: transparent;
}

.signal-panel ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.signal-panel li {
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.signal-panel li:last-child {
  border-bottom: 0;
}

.signal-panel strong {
  display: block;
  color: var(--cyan);
  margin-bottom: 4px;
}

.signal-panel span {
  color: rgba(255, 255, 255, 0.78);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 430px);
  gap: 28px;
  align-items: start;
  background: var(--soft);
}

.download-box {
  flex-direction: column;
  align-items: flex-start;
  padding: 24px;
  border: 1px solid #dfe3eb;
  border-radius: 8px;
  background: var(--paper);
}

.download-box code {
  display: block;
  width: 100%;
  padding: 14px;
  border-radius: 6px;
  background: var(--ink);
  color: var(--cyan);
  font-family: Menlo, Consolas, monospace;
}

.download-box p {
  font-size: 14px;
  margin-bottom: 0;
}

.contact {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 28px;
}

.contact-link {
  color: var(--blue);
  font-size: 24px;
  font-weight: 700;
  text-decoration: none;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  padding: 24px 36px;
  background: var(--ink);
  color: rgba(255, 255, 255, 0.7);
  font-size: 13px;
}

@media (max-width: 860px) {
  .site-header {
    height: auto;
    min-height: 72px;
    padding: 12px 18px;
    align-items: flex-start;
    flex-direction: column;
  }

  .top-nav {
    gap: 14px;
    flex-wrap: wrap;
  }

  .hero-copy {
    padding: 154px 20px 54px;
  }

  h1 {
    font-size: 42px;
  }

  h2 {
    font-size: 30px;
  }

  .section,
  .band {
    padding: 56px 20px;
  }

  #fixie {
    min-height: auto;
    padding-top: 56px;
    padding-bottom: 56px;
  }

  #fixie h2 {
    font-size: 30px;
  }

  #fixie .lead {
    font-size: 18px;
  }

  .feature-grid,
  .band,
  .split {
    grid-template-columns: 1fr;
  }

  .signal-panel {
    grid-template-columns: 1fr;
  }

  .contact {
    display: block;
  }
}