:root {
  --bg: #eef1f0;
  --surface: #ffffff;
  --surface-soft: #f7f8f6;
  --ink: #1c2421;
  --muted: #60706b;
  --line: #d8dfdc;
  --teal: #0c7c72;
  --teal-dark: #07564f;
  --amber: #c7832b;
  --red: #b94738;
  --graphite: #27302d;
  --shadow: 0 18px 50px rgba(28, 36, 33, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
}

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 10;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 32px;
  color: #fff;
  background: rgba(22, 28, 26, 0.72);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
}

.brand-mark {
  width: 20px;
  height: 20px;
  border: 2px solid #cfe7df;
  border-radius: 50%;
  position: relative;
}

.brand-mark::after {
  content: "";
  position: absolute;
  width: 8px;
  height: 8px;
  right: -5px;
  bottom: -3px;
  background: var(--amber);
  border-radius: 50%;
}

.nav-links {
  display: flex;
  gap: 22px;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.78);
}

.nav-links a:hover {
  color: #fff;
}

.hero {
  position: relative;
  min-height: 92vh;
  display: grid;
  align-items: center;
  padding: 118px 32px 72px;
  overflow: hidden;
  background: #18211f;
  color: #fff;
}

#knowledge-canvas,
.hero-shade {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-shade {
  background:
    linear-gradient(90deg, rgba(16, 22, 20, 0.96) 0%, rgba(16, 22, 20, 0.82) 38%, rgba(16, 22, 20, 0.2) 100%),
    linear-gradient(180deg, rgba(16, 22, 20, 0.18) 0%, rgba(16, 22, 20, 0.76) 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 830px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--amber);
  font-size: 13px;
  font-weight: 800;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  max-width: 780px;
  font-size: 64px;
  line-height: 1.06;
}

.hero-copy {
  max-width: 680px;
  margin: 24px 0 0;
  color: rgba(255, 255, 255, 0.78);
  font-size: 18px;
}

.hero-actions,
.contact-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.primary-link,
.secondary-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 6px;
  font-weight: 700;
  border: 1px solid transparent;
}

.primary-link {
  background: var(--teal);
  color: #fff;
}

.primary-link:hover {
  background: var(--teal-dark);
}

.secondary-link {
  border-color: rgba(255, 255, 255, 0.38);
  color: #fff;
}

.secondary-link:hover {
  border-color: rgba(255, 255, 255, 0.76);
}

.signal-panel {
  position: absolute;
  right: 32px;
  bottom: 36px;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(3, minmax(120px, 1fr));
  gap: 1px;
  width: min(560px, calc(100% - 64px));
  background: rgba(255, 255, 255, 0.18);
  border: 1px solid rgba(255, 255, 255, 0.18);
}

.signal-panel > div {
  padding: 18px;
  background: rgba(13, 20, 18, 0.62);
}

.metric {
  display: block;
  font-size: 22px;
  font-weight: 800;
}

.metric-label {
  display: block;
  margin-top: 4px;
  color: rgba(255, 255, 255, 0.64);
  font-size: 13px;
}

.section {
  padding: 92px 32px;
}

.section-heading {
  max-width: 720px;
  margin-bottom: 34px;
}

.section-heading h2,
.contact-copy h2 {
  margin: 0;
  font-size: 40px;
  line-height: 1.16;
}

.section-heading p:not(.eyebrow),
.contact-copy p {
  color: var(--muted);
  font-size: 17px;
}

.intro-band {
  background: var(--surface);
}

.focus-grid,
.systems-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.focus-card,
.system-card,
.principles article,
.timeline-item {
  background: var(--surface-soft);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 24px;
}

.focus-card h3,
.system-card h3,
.principles h3,
.timeline h3 {
  margin: 0 0 10px;
  font-size: 18px;
}

.focus-card p,
.system-card p,
.principles p,
.timeline p {
  margin: 0;
  color: var(--muted);
}

.split-section {
  display: grid;
  grid-template-columns: minmax(280px, 0.85fr) minmax(320px, 1.15fr);
  gap: 58px;
  background: #e7ece9;
}

.sticky-heading {
  position: sticky;
  top: 100px;
  align-self: start;
}

.timeline {
  display: grid;
  gap: 14px;
}

.timeline-item {
  display: grid;
  grid-template-columns: 68px 1fr;
  gap: 8px 18px;
  align-items: start;
  background: #fff;
}

.timeline-item .step {
  grid-row: span 2;
  color: var(--teal);
  font-size: 28px;
  font-weight: 900;
}

.agent-section {
  background: var(--graphite);
  color: #fff;
}

.agent-section .section-heading p:not(.eyebrow),
.agent-section .principles p {
  color: rgba(255, 255, 255, 0.66);
}

.architecture {
  position: relative;
  display: grid;
  grid-template-columns: repeat(5, minmax(140px, 1fr));
  gap: 12px;
  margin-bottom: 22px;
}

.arch-node {
  min-height: 120px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 18px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.07);
}

.arch-node.core {
  background: var(--teal);
}

.arch-node span {
  font-size: 18px;
  font-weight: 800;
}

.arch-node small {
  color: rgba(255, 255, 255, 0.68);
}

.principles {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.principles article {
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.12);
}

.systems-band {
  background: var(--surface);
}

.writing-section {
  background: #f1ece4;
}

.notes-list {
  display: grid;
  gap: 10px;
  max-width: 980px;
}

.notes-list a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 20px 22px;
  background: rgba(255, 255, 255, 0.58);
  border: 1px solid rgba(71, 61, 46, 0.14);
  border-radius: 8px;
}

.notes-list a:hover {
  background: #fff;
}

.notes-list span {
  font-weight: 800;
}

.notes-list small {
  color: #786b58;
}

.contact-section {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  background: #17201e;
  color: #fff;
}

.contact-copy {
  max-width: 760px;
}

.contact-copy p {
  color: rgba(255, 255, 255, 0.72);
  font-size: 17px;
}

@media (max-width: 980px) {
  .site-header {
    height: auto;
    min-height: 64px;
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
    padding: 14px 18px;
  }

  .nav-links {
    width: 100%;
    overflow-x: auto;
    gap: 16px;
    padding-bottom: 4px;
  }

  .hero {
    min-height: 860px;
    padding: 132px 20px 190px;
  }

  .hero h1 {
    font-size: 44px;
  }

  .signal-panel {
    left: 20px;
    right: 20px;
    bottom: 24px;
    width: auto;
    grid-template-columns: 1fr;
  }

  .section {
    padding: 68px 20px;
  }

  .focus-grid,
  .systems-grid,
  .principles,
  .architecture,
  .split-section {
    grid-template-columns: 1fr;
  }

  .sticky-heading {
    position: static;
  }

  .contact-section {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 560px) {
  .hero h1,
  .section-heading h2,
  .contact-copy h2 {
    font-size: 34px;
  }

  .hero-copy {
    font-size: 16px;
  }

  .timeline-item {
    grid-template-columns: 1fr;
  }

  .timeline-item .step {
    grid-row: auto;
  }

  .notes-list a {
    align-items: flex-start;
    flex-direction: column;
  }
}