:root {
  --ink: #17201c;
  --muted: #5c6b64;
  --paper: #f7f8f4;
  --surface: #ffffff;
  --line: #dfe6df;
  --field: #446356;
  --signal: #d99a3a;
  --sky: #d9e9ef;
  --deep: #0f1917;
  --shadow: 0 18px 45px rgba(20, 32, 28, 0.14);
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.55;
}

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

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

.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 18px clamp(18px, 4vw, 48px);
  color: #fff;
  transition: background 180ms ease, box-shadow 180ms ease, color 180ms ease;
}

.site-header.is-scrolled {
  color: var(--ink);
  background: rgba(247, 248, 244, 0.94);
  box-shadow: 0 1px 0 rgba(23, 32, 28, 0.08);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  width: clamp(178px, 22vw, 286px);
  padding: 5px 8px;
  border-radius: 6px;
  background: rgba(24, 21, 25, 0.88);
}

.brand img {
  width: 100%;
  height: auto;
  object-fit: contain;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  font-weight: 700;
}

.site-nav a {
  padding: 9px 12px;
  border-radius: 6px;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  background: rgba(255, 255, 255, 0.16);
  outline: none;
}

.site-header.is-scrolled .site-nav a:hover,
.site-header.is-scrolled .site-nav a:focus-visible {
  background: #e9eee8;
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid currentColor;
  border-radius: 6px;
  background: transparent;
  color: inherit;
  place-items: center;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  margin: 3px auto;
}

.hero {
  position: relative;
  min-height: 92vh;
  display: grid;
  align-items: end;
  overflow: hidden;
  background: var(--deep);
}

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

.hero-shade {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(9, 18, 17, 0.88), rgba(9, 18, 17, 0.46) 52%, rgba(9, 18, 17, 0.22)),
              linear-gradient(0deg, rgba(9, 18, 17, 0.78), rgba(9, 18, 17, 0.05) 45%);
}

.hero-content {
  position: relative;
  z-index: 1;
  width: min(920px, calc(100% - 36px));
  margin: 0 auto;
  padding: 132px 0 13vh;
  color: #fff;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--signal);
  font-size: 13px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0;
}

.hero h1 {
  margin: 0;
  font-size: clamp(46px, 9vw, 112px);
  line-height: 0.94;
  letter-spacing: 0;
}

.hero-lead {
  width: min(720px, 100%);
  margin: 24px 0 0;
  font-size: clamp(18px, 2.4vw, 27px);
  color: rgba(255, 255, 255, 0.9);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 12px 18px;
  border-radius: 6px;
  font-weight: 800;
  border: 1px solid rgba(255, 255, 255, 0.5);
}

.button.primary {
  color: #15211d;
  background: var(--signal);
  border-color: var(--signal);
}

.button.primary + .button.primary {
  color: #fff;
  background: rgba(68, 99, 86, 0.78);
  border-color: rgba(255, 255, 255, 0.42);
}

.button.secondary {
  color: #fff;
  background: rgba(255, 255, 255, 0.12);
}

.wrap {
  width: min(1180px, calc(100% - 36px));
  margin: 0 auto;
}

.summary-band {
  padding: 48px 0;
  background: var(--deep);
  color: #f4f6ef;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: clamp(28px, 5vw, 78px);
  align-items: start;
}

h2 {
  margin: 0;
  font-size: clamp(30px, 4.6vw, 56px);
  line-height: 1.03;
  letter-spacing: 0;
}

h3 {
  margin: 0 0 12px;
  font-size: 22px;
  line-height: 1.2;
  letter-spacing: 0;
}

p {
  margin: 0;
}

.split > p {
  color: #d9e4dc;
  font-size: 19px;
}

.section {
  padding: clamp(66px, 8vw, 112px) 0;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.feature-card,
.spec-list div,
.doc-panel,
.faq-list details {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 1px 0 rgba(23, 32, 28, 0.03);
}

.feature-card {
  min-height: 220px;
  padding: 26px;
}

.feature-kicker {
  display: block;
  margin-bottom: 34px;
  color: var(--field);
  font-weight: 900;
}

.feature-card p,
.section-head p,
.doc-panel p,
.doc-panel li,
.faq-list p,
.timeline span,
.spec-list p {
  color: var(--muted);
}

.system {
  background: #edf3ee;
}

.section-head {
  max-width: 860px;
  margin-bottom: 38px;
}

.section-head p {
  margin-top: 18px;
  font-size: 18px;
}

.section-head.compact {
  max-width: 720px;
}

.system-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.9fr);
  gap: 22px;
  align-items: stretch;
}

.flow {
  padding: clamp(22px, 4vw, 42px);
  background: #13231f;
  color: #fff;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.flow-node {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 18px;
  align-items: baseline;
  padding: 18px 0;
}

.flow-node strong {
  font-size: 24px;
}

.flow-node span {
  color: #c9d7cf;
}

.flow-line {
  height: 1px;
  background: rgba(255, 255, 255, 0.2);
}

.spec-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.spec-list div {
  padding: 20px;
}

.spec-list span {
  display: block;
  margin-bottom: 5px;
  font-size: 26px;
  font-weight: 900;
  color: var(--field);
}

.field {
  background: var(--surface);
}

.harmonics {
  background: #f7f8f4;
}

.harmonics-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(300px, 0.75fr);
  gap: 18px;
  align-items: start;
}

.acoustic-note {
  display: grid;
  gap: 18px;
  padding: clamp(24px, 4vw, 38px);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.acoustic-note p,
.harmonics-summary {
  color: #34443d;
  font-size: 18px;
}

.harmonic-points {
  display: grid;
  gap: 12px;
}

.harmonic-points div {
  padding: 20px;
  background: #13231f;
  color: #fff;
  border-radius: 8px;
}

.harmonic-points span {
  display: block;
  margin-bottom: 8px;
  color: var(--signal);
  font-size: 22px;
  font-weight: 900;
}

.harmonic-points p {
  color: #d5e0d8;
}

.harmonics-summary {
  margin-top: 18px;
  padding: 22px;
  border-left: 4px solid var(--signal);
  background: #eef4ee;
  border-radius: 8px;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: steps;
}

.timeline li {
  counter-increment: steps;
  min-height: 132px;
  padding: 22px 22px 22px 72px;
  border-left: 3px solid var(--signal);
  background: var(--paper);
  border-radius: 8px;
  position: relative;
}

.timeline li::before {
  content: counter(steps, decimal-leading-zero);
  position: absolute;
  left: 20px;
  top: 22px;
  font-weight: 900;
  color: var(--field);
}

.timeline strong,
.timeline span {
  display: block;
}

.timeline strong {
  margin-bottom: 8px;
}

.docs {
  background: #f3f5f0;
}

.doc-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.tab {
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 10px 14px;
  background: #fff;
  color: var(--ink);
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}

.tab.active {
  background: var(--field);
  border-color: var(--field);
  color: #fff;
}

.doc-panel {
  display: none;
  padding: clamp(24px, 4vw, 38px);
}

.doc-panel.active {
  display: block;
}

.doc-panel ul {
  display: grid;
  gap: 10px;
  margin: 20px 0 0;
  padding-left: 20px;
}

.doc-article {
  max-width: 960px;
}

.doc-article h4 {
  margin: 30px 0 10px;
  font-size: clamp(1.1rem, 2vw, 1.35rem);
}

.doc-article p {
  margin: 12px 0;
}

.doc-article code {
  overflow-wrap: anywhere;
}

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

.faq-list {
  display: grid;
  gap: 12px;
}

.faq-list details {
  padding: 20px 22px;
}

.faq-list summary {
  cursor: pointer;
  font-weight: 900;
}

.faq-list p {
  margin-top: 12px;
}

.contacts {
  background: #edf3ee;
}

.download {
  background: var(--surface);
}

.download-card,
.contact-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 28px;
  align-items: center;
  padding: clamp(26px, 5vw, 46px);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.download-card + .download-card {
  margin-top: 18px;
}

.download-card h2,
.contact-card h2 {
  margin-bottom: 14px;
}

.download-card p:not(.eyebrow),
.contact-card p:not(.eyebrow) {
  color: var(--muted);
}

.download-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.download-meta span {
  padding: 7px 10px;
  color: var(--field);
  background: #edf3ee;
  border: 1px solid var(--line);
  border-radius: 6px;
  font-size: 14px;
  font-weight: 800;
}

.checksum {
  margin-top: 16px;
  max-width: 820px;
}

.checksum code {
  display: inline-block;
  max-width: 100%;
  padding: 3px 6px;
  color: #13231f;
  background: #edf3ee;
  border-radius: 4px;
  overflow-wrap: anywhere;
  font-size: 13px;
}

.download-button,
.contact-mail {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 13px 18px;
  color: #fff;
  background: var(--field);
  border-radius: 6px;
  font-weight: 900;
}

.install-guide {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 14px;
}

.install-guide div {
  padding: 18px;
  background: #f7f8f4;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.install-guide strong {
  display: block;
  margin-bottom: 8px;
  color: var(--ink);
}

.install-guide p {
  color: var(--muted);
  font-size: 15px;
}

.security-note {
  margin-top: 14px;
  color: var(--muted);
  font-size: 15px;
}

.site-footer {
  padding: 46px 0;
  background: var(--deep);
  color: #eef4ee;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 0.7fr 0.7fr;
  gap: 28px;
}

.site-footer p,
.site-footer a {
  color: #cbd8d0;
}

.site-footer span,
.site-footer strong {
  display: block;
  margin-bottom: 10px;
  font-weight: 900;
}

.footer-logo {
  width: min(280px, 100%);
  margin-bottom: 18px;
  border-radius: 6px;
}

.site-footer a {
  display: block;
  margin: 6px 0;
}

@media (max-width: 820px) {
  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: calc(100% - 8px);
    right: 18px;
    left: 18px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 10px;
    color: var(--ink);
    background: rgba(247, 248, 244, 0.98);
    border: 1px solid var(--line);
    border-radius: 8px;
    box-shadow: var(--shadow);
  }

  .site-nav.is-open {
    display: flex;
  }

  .site-nav a {
    padding: 12px;
  }

  .hero {
    min-height: 88vh;
  }

  .hero-content {
    padding-bottom: 10vh;
  }

  .split,
  .feature-grid,
  .system-layout,
  .harmonics-layout,
  .timeline,
  .download-card,
  .install-guide,
  .contact-card,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .flow-node {
    grid-template-columns: 1fr;
    gap: 6px;
  }
}

@media (max-width: 520px) {
  .site-header {
    padding: 14px 18px;
  }

  .brand {
    width: min(190px, calc(100vw - 104px));
  }

  .hero-actions,
  .doc-tabs {
    flex-direction: column;
  }

  .button,
  .tab,
  .download-button,
  .contact-mail {
    width: 100%;
  }

  .feature-card {
    min-height: auto;
  }

  .timeline li {
    padding-left: 58px;
  }
}