:root {
  --bg: #f6f6f6;
  --bg-soft: #efefef;
  --surface-dark: #242424;
  --surface-cta: #1a1a1a;
  --line: rgba(0, 0, 0, 0.1);
  --line-strong: rgba(0, 0, 0, 0.16);
  --line-inv: rgba(255, 255, 255, 0.12);
  --text: #111111;
  --text-muted: #666666;
  --text-inv: #ebebeb;
  --text-inv-muted: rgba(220, 220, 220, 0.68);
  --accent: #1f8f5f;
  --accent-strong: #166b47;
  --container: 1160px;
  --radius-sm: 5px;
}

*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 4rem;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
  color: var(--text);
  line-height: 1.6;
  background: var(--bg);
}

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

pre, code {
  font-family: Consolas, "SFMono-Regular", "Liberation Mono", Menlo, monospace;
}

/* Accessibility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -3rem;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  background: var(--accent-strong);
  color: #fff;
  font-weight: 600;
}

.skip-link:focus {
  top: 1rem;
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid rgba(31, 143, 95, 0.35);
  outline-offset: 2px;
}

/* Layout */
.container {
  width: min(calc(100% - 2rem), var(--container));
  margin: 0 auto;
}

/* Section bands */
.section {
  padding: 5rem 0;
  scroll-margin-top: 4rem;
}

section[id] {
  scroll-margin-top: 4rem;
}

.section--hero {
  padding-top: 3rem;
  padding-bottom: 3.5rem;
  border-bottom: 1px solid var(--line);
}

.section--soft {
  background: var(--bg-soft);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section--dark {
  background: var(--surface-dark);
  color: var(--text-inv);
}

.section--cta {
  background: #f1f1f1;
  color: var(--text);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding-top: 4rem;
  padding-bottom: 4.5rem;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(8px);
  background: rgba(246, 246, 246, 0.82);
  border-bottom: 1px solid rgba(0, 0, 0, 0.07);
}

.site-header__inner,
.site-footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.site-header__inner {
  min-height: 3.25rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
}

.brand__logo {
  width: 2rem;
  height: 2rem;
  border-radius: 0.65rem;
  flex-shrink: 0;
}

.brand__name {
  font-size: 1.18rem;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.footer-title {
  font-weight: 700;
  letter-spacing: -0.03em;
  margin: 0;
}

.site-nav {
  display: inline-flex;
  align-items: center;
  gap: 1.1rem;
  font-size: 0.82rem;
}

.site-nav a {
  color: var(--text-muted);
  transition: color 0.15s;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--accent-strong);
}

/* Buttons */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  min-height: 2.6rem;
  padding: 0 1.1rem;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  font-weight: 600;
  font-size: 0.92rem;
  transition: opacity 0.15s;
  cursor: pointer;
}

.button:hover,
.button:focus-visible {
  opacity: 0.85;
}

.button--small {
  min-height: 2.1rem;
  padding: 0 0.85rem;
  font-size: 0.85rem;
  background: transparent;
  border-color: var(--line-strong);
  color: var(--text);
}

.button--primary {
  color: #fff;
  background: var(--accent);
  border-color: var(--accent-strong);
}

.button--ghost {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--text);
}

.button--ghost-inv {
  background: transparent;
  border-color: var(--line-inv);
  color: var(--text-inv);
}

/* Typography primitives */
.eyebrow {
  margin: 0 0 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.74rem;
  font-weight: 700;
  color: var(--accent);
}

.section--dark .eyebrow,
.section--cta .eyebrow {
  color: var(--accent);
}

.section-heading {
  max-width: 52rem;
  margin-bottom: 2.5rem;
}

.section-heading h2 {
  margin: 0 0 0.6rem;
  font-size: clamp(1.9rem, 3.5vw, 3rem);
  letter-spacing: -0.04em;
  line-height: 1.1;
}

.section-heading p {
  margin: 0;
  color: var(--text-muted);
  max-width: 46rem;
}

.section--dark .section-heading p,
.section--dark .section-heading h2 {
  color: var(--text-inv);
}

.section--dark .section-heading p {
  color: var(--text-inv-muted);
}

.section-heading--compact {
  margin-bottom: 1.5rem;
}

.section-divider {
  height: 1px;
  background: var(--line);
  margin: 3rem 0;
}

/* Hero band */
.hero__title {
  margin: 0 0 1rem;
  font-size: clamp(2.5rem, 5.5vw, 4.2rem);
  letter-spacing: -0.05em;
  line-height: 1.05;
  max-width: 16ch;
}

.hero__lead {
  margin: 0 0 1.8rem;
  max-width: 44rem;
  font-size: 1.06rem;
  color: var(--text-muted);
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

/* Technical pillars — numbered matrix */
.pillar-matrix {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  column-gap: 3rem;
  border-top: 1px solid var(--line);
}

.pillar-row {
  display: grid;
  grid-template-columns: 2.5rem 1fr;
  gap: 0 1rem;
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--line);
  align-items: start;
}

.pillar-row__num {
  font-size: 0.74rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
  padding-top: 0.18rem;
}

.pillar-row__body h3 {
  margin: 0 0 0.35rem;
  font-size: 0.97rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.pillar-row__body p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.93rem;
}

/* Adoption flow — ruled column band */
.steps-band {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.step-row {
  padding: 1.5rem 1.5rem 1.5rem 1.5rem;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.step-row__head {
  display: flex;
  align-items: baseline;
  gap: 0.65rem;
  margin-bottom: 0.7rem;
}

.step-row__num {
  font-size: 0.74rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.08em;
  flex-shrink: 0;
  font-variant-numeric: tabular-nums;
}

.step-row__head h3 {
  margin: 0;
  font-size: 0.97rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.step-row__text {
  margin: 0 0 0.5rem;
  color: var(--text-muted);
  font-size: 0.93rem;
}

.step-row__meta {
  font-size: 0.8rem;
  font-family: Consolas, "SFMono-Regular", monospace;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

/* Runtime architecture — dark band with layer rows */
.architecture-summary {
  margin: 0 0 2rem;
  max-width: 50rem;
  color: var(--text-inv-muted);
  font-size: 0.97rem;
}

.layer-stack {
  border-top: 1px solid var(--line-inv);
}

.layer-row {
  display: grid;
  grid-template-columns: minmax(0, 170px) minmax(0, 210px) 1fr;
  gap: 1.5rem;
  align-items: start;
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--line-inv);
}

.layer-row__label {
  margin: 0;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-inv);
  text-transform: uppercase;
  letter-spacing: 0.07em;
}

.layer-row__detail {
  margin: 0;
}

.layer-row__detail code {
  font-size: 0.85rem;
  color: #a0d4b0;
  background: rgba(255, 255, 255, 0.06);
  padding: 0.18rem 0.45rem;
  border-radius: 3px;
}

.layer-row__text {
  margin: 0;
  color: var(--text-inv-muted);
  font-size: 0.93rem;
}

/* Product surfaces — two-column flat grid */
.surface-index {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-top: 1px solid var(--line);
}

.surface-row {
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  padding: 1.6rem 0;
  border-bottom: 1px solid var(--line);
}

.surface-row:nth-child(odd) {
  padding-right: 2.5rem;
  border-right: 1px solid var(--line);
}

.surface-row:nth-child(even) {
  padding-left: 2.5rem;
}

.surface-row__type {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.surface-row__image {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border-radius: 0.8rem;
  border: 1px solid var(--line);
  background: #0f0f0f;
  margin-bottom: 0.15rem;
}

.surface-row__name {
  margin: 0;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.surface-row__text {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.93rem;
  flex-grow: 1;
}

/* Docs + FAQ — flat knowledge band */
.knowledge-section {
  padding: 0;
}

.docs-list {
  border-top: 1px solid var(--line);
}

.docs-entry {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1rem;
  align-items: baseline;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--line);
}

.docs-entry:hover .docs-entry__title,
.docs-entry:focus-visible .docs-entry__title {
  color: var(--accent-strong);
}

.docs-entry__title {
  font-weight: 700;
  font-size: 0.93rem;
}

.docs-entry__note {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.faq-list {
  border-top: 1px solid var(--line);
}

.faq-entry {
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--line);
}

.faq-entry h3 {
  margin: 0 0 0.4rem;
  font-size: 0.97rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.faq-entry p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.93rem;
}

/* Text link */
.text-link {
  display: inline-flex;
  font-weight: 700;
  font-size: 0.85rem;
  color: var(--accent-strong);
}

.text-link:hover,
.text-link:focus-visible {
  color: var(--accent);
}

/* Final CTA band */
.cta-band__title {
  margin: 0 0 0.75rem;
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  letter-spacing: -0.04em;
  line-height: 1.1;
  color: var(--text);
}

.cta-band__text {
  margin: 0 0 1.8rem;
  max-width: 44rem;
  color: var(--text-muted);
}

.cta-band__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

/* Footer */
.site-footer {
  padding: 2rem 0 3rem;
  border-top: 1px solid var(--line);
}

.footer-copy {
  color: var(--text-muted);
  margin: 0.25rem 0 0;
  font-size: 0.88rem;
}

.footer-links {
  display: flex;
  gap: 1.25rem;
}

.footer-links a {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.footer-links a:hover,
.footer-links a:focus-visible {
  color: var(--accent-strong);
}

/* Responsive — tablet */
@media (max-width: 1080px) {
  .site-header__inner {
    flex-wrap: wrap;
    min-height: auto;
    padding: 0.9rem 0;
  }

  .site-nav {
    order: 3;
    flex: 1 1 100%;
    flex-wrap: wrap;
  }

  .pillar-matrix {
    grid-template-columns: 1fr;
    column-gap: 0;
  }

  .layer-row {
    grid-template-columns: 1fr;
    gap: 0.4rem;
  }
}

/* Responsive — mobile */
@media (max-width: 760px) {
  .section {
    padding: 3.5rem 0;
  }

  .site-header__inner,
  .site-footer__inner {
    display: grid;
    justify-content: stretch;
  }

  .site-nav {
    flex-wrap: wrap;
  }

  .brand__logo {
    width: 1.8rem;
    height: 1.8rem;
    border-radius: 0.55rem;
  }

  .brand__name {
    font-size: 1.05rem;
  }

  .hero__title {
    font-size: clamp(2.3rem, 14vw, 3.8rem);
    max-width: none;
  }

  .steps-band {
    grid-template-columns: 1fr;
    border-left: none;
    border-top: none;
  }

  .step-row {
    border-top: 1px solid var(--line);
    border-right: none;
    padding: 1.25rem 0;
  }

  .surface-index {
    grid-template-columns: 1fr;
  }

  .surface-row:nth-child(odd) {
    padding-right: 0;
    border-right: none;
  }

  .surface-row:nth-child(even) {
    padding-left: 0;
  }

  .footer-links {
    flex-direction: column;
    gap: 0.6rem;
  }

  .cta-band__actions {
    flex-direction: column;
    align-items: flex-start;
  }
}