:root {
  color-scheme: dark;
  --bg: #080d12;
  --panel: #101820;
  --panel-2: #151e28;
  --line: rgba(255, 255, 255, 0.12);
  --text: #f6f8fb;
  --muted: #aeb9c7;
  --red: #ec3d32;
  --amber: #f7a43b;
  --blue: #39a8ff;
  --green: #36d585;
  --radius: 8px;
  font-family: Inter, "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  letter-spacing: 0;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 68px;
  padding: 14px clamp(18px, 4vw, 56px);
  border-bottom: 1px solid var(--line);
  background: rgba(8, 13, 18, 0.86);
  backdrop-filter: blur(16px);
}

.language-select {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 36px;
  color: var(--muted);
  font-size: 13px;
  white-space: nowrap;
}

.language-select select {
  min-height: 36px;
  max-width: 150px;
  border: 1px solid rgba(139, 208, 255, 0.42);
  border-radius: 6px;
  background: #101820;
  color: #f6f8fb;
  padding: 0 10px;
  font: inherit;
  color-scheme: dark;
}

.language-select select:focus-visible {
  outline: 2px solid rgba(57, 168, 255, 0.82);
  outline-offset: 2px;
}

.language-select option {
  background: #101820;
  color: #f6f8fb;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-height: 40px;
  font-weight: 800;
  white-space: nowrap;
}

.brand-logo {
  width: auto;
  height: 30px;
  max-width: 150px;
  flex: 0 0 auto;
  object-fit: contain;
}

.brand span {
  min-height: 26px;
  border-left: 1px solid rgba(255, 255, 255, 0.2);
  padding-left: 12px;
  color: var(--text);
  font-size: clamp(14px, 1.2vw, 17px);
  line-height: 1.2;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
}

.nav a {
  min-height: 36px;
  padding: 9px 12px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 14px;
}

.nav a:hover {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text);
}

.hero {
  display: grid;
  grid-template-columns: minmax(320px, 0.82fr) minmax(420px, 1.18fr);
  align-items: stretch;
  min-height: calc(100svh - 68px);
  border-bottom: 1px solid var(--line);
}

.hero-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: clamp(40px, 7vw, 94px) clamp(22px, 5vw, 72px);
  background:
    linear-gradient(145deg, rgba(236, 61, 50, 0.13), transparent 44%),
    linear-gradient(180deg, #0e141b, #080d12);
}

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

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

h1 {
  max-width: 680px;
  margin-bottom: 22px;
  font-size: clamp(38px, 5.5vw, 76px);
  line-height: 1.02;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 16px;
  font-size: clamp(28px, 3.5vw, 48px);
  line-height: 1.12;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 20px;
  line-height: 1.28;
}

.lead,
.section-heading p,
.panel-copy p,
.risk-grid p,
.install-grid p,
.device-grid p,
.footer p {
  color: var(--muted);
  line-height: 1.75;
}

.lead {
  max-width: 660px;
  margin-bottom: 30px;
  font-size: 18px;
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid var(--line);
  border-radius: 6px;
  font-weight: 800;
}

.button.primary {
  border-color: rgba(236, 61, 50, 0.8);
  background: var(--red);
  color: #fff;
}

.button.secondary {
  background: rgba(255, 255, 255, 0.06);
}

.hero-visual {
  position: relative;
  min-height: 520px;
  margin: 0;
  overflow: hidden;
}

.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 700ms ease;
}

.hero-slide.active {
  opacity: 1;
}

.hero-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(8, 13, 18, 0.74), transparent 38%);
  pointer-events: none;
}

.hero-switcher {
  position: absolute;
  right: clamp(18px, 3vw, 42px);
  bottom: clamp(18px, 3vw, 42px);
  z-index: 2;
  display: flex;
  gap: 10px;
}

.hero-dot {
  width: 34px;
  height: 8px;
  border: 0;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.38);
  cursor: pointer;
}

.hero-dot.active {
  background: var(--red);
  box-shadow: 0 0 18px rgba(236, 61, 50, 0.62);
}

.section {
  padding: clamp(56px, 8vw, 108px) clamp(18px, 4vw, 56px);
}

.section-heading {
  max-width: 920px;
  margin-bottom: 34px;
}

.section-heading.compact {
  max-width: 1080px;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-bottom: 18px;
}

.metric,
.risk-grid article,
.install-grid article,
.device-grid article {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.065), rgba(255, 255, 255, 0.025));
}

.metric {
  min-height: 172px;
  padding: 22px;
}

.metric span {
  display: block;
  margin-bottom: 14px;
  color: var(--muted);
  font-weight: 700;
}

.metric strong {
  display: block;
  margin-bottom: 10px;
  font-size: clamp(34px, 5vw, 58px);
  line-height: 1;
}

.metric p {
  margin: 0;
  color: var(--muted);
}

.metric.accent {
  border-color: rgba(236, 61, 50, 0.42);
  box-shadow: inset 0 0 0 1px rgba(236, 61, 50, 0.12);
}

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

.risk-grid article,
.install-grid article,
.device-grid article {
  padding: 24px;
}

.systems {
  background:
    linear-gradient(180deg, rgba(57, 168, 255, 0.07), transparent 34%),
    #0a1118;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.system-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 18px;
}

.tab {
  min-height: 42px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.05);
  color: var(--muted);
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}

.tab.active {
  border-color: rgba(57, 168, 255, 0.8);
  background: rgba(57, 168, 255, 0.16);
  color: var(--text);
}

.system-panel {
  display: none;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #070b10;
}

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

.panel-copy {
  display: grid;
  grid-template-columns: minmax(240px, 0.35fr) minmax(320px, 1fr);
  gap: 22px;
  align-items: start;
  padding: 22px 24px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(90deg, rgba(236, 61, 50, 0.1), rgba(57, 168, 255, 0.08));
}

.panel-label {
  display: inline-flex;
  width: fit-content;
  min-height: 30px;
  align-items: center;
  padding: 0 10px;
  border-radius: 999px;
  background: rgba(247, 164, 59, 0.15);
  color: var(--amber);
  font-size: 13px;
  font-weight: 900;
}

.panel-copy h3,
.panel-copy p {
  grid-column: 2;
}

.panel-copy h3 {
  margin-bottom: 8px;
}

.panel-copy p {
  margin-bottom: 0;
}

.system-panel img {
  width: 100%;
  aspect-ratio: 1672 / 941;
  object-fit: cover;
}

.wireless {
  background:
    linear-gradient(135deg, rgba(236, 61, 50, 0.1), transparent 45%),
    linear-gradient(180deg, #0a1118, #080d12);
}

.wireless-layout {
  display: grid;
  grid-template-columns: minmax(300px, 0.85fr) minmax(320px, 1.15fr);
  gap: 28px;
  align-items: start;
}

.wireless-points {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.wireless-points div {
  min-height: 126px;
  padding: 20px;
  border: 1px solid rgba(236, 61, 50, 0.24);
  border-radius: var(--radius);
  background: rgba(236, 61, 50, 0.08);
}

.wireless-points strong {
  display: block;
  margin-bottom: 8px;
  font-size: 26px;
}

.wireless-points span {
  color: var(--muted);
  line-height: 1.6;
}

.device-grid {
  grid-template-columns: repeat(6, minmax(0, 1fr));
  margin-top: 22px;
}

.device-grid article {
  min-height: 232px;
  padding: 18px;
}

.device-icon {
  display: block;
  width: 58px;
  height: 58px;
  margin-bottom: 18px;
  border: 2px solid rgba(255, 255, 255, 0.78);
  box-shadow: 0 0 22px rgba(236, 61, 50, 0.2);
}

.device-icon.detector,
.device-icon.heat {
  border-radius: 50%;
  background: radial-gradient(circle, #f8fbff 0 42%, #cfd6dd 43% 52%, #f3f6f8 53%);
}

.device-icon.heat {
  background: radial-gradient(circle, #fff 0 28%, #d9dee3 29% 46%, #f4f6f7 47%);
}

.device-icon.call {
  border-radius: 6px;
  background: linear-gradient(#d92322, #8d1718);
}

.device-icon.strobe {
  border-radius: 6px;
  background: linear-gradient(#eef2f6 0 48%, #b60f17 49% 100%);
}

.device-icon.module,
.device-icon.isolator {
  border-radius: 6px;
  background: linear-gradient(180deg, #f5f7f9, #d5dce2);
}

.device-icon.isolator::after {
  content: "";
  display: block;
  width: 34px;
  height: 12px;
  margin: 31px auto 0;
  border-radius: 2px;
  background: #5b646e;
}

.install {
  background: #0b1016;
}

.install-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.cta {
  display: grid;
  grid-template-columns: minmax(320px, 0.8fr) minmax(360px, 1.2fr);
  gap: 24px;
  align-items: center;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(90deg, rgba(57, 168, 255, 0.1), rgba(54, 213, 133, 0.08)),
    #0d141b;
}

.contact {
  display: grid;
  grid-template-columns: minmax(320px, 0.75fr) minmax(420px, 1.25fr);
  gap: 28px;
  align-items: start;
  background:
    linear-gradient(135deg, rgba(236, 61, 50, 0.12), transparent 42%),
    #080d12;
}

.contact > div:first-child {
  max-width: 680px;
}

.contact > div:first-child p:last-child {
  color: var(--muted);
  line-height: 1.75;
}

.contact-cards {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.contact-card {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 118px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.075), rgba(255, 255, 255, 0.03));
}

.contact-card span {
  margin-bottom: 8px;
  color: var(--amber);
  font-size: 13px;
  font-weight: 900;
  text-transform: uppercase;
}

.contact-card strong {
  color: var(--text);
  font-size: 18px;
  line-height: 1.35;
  overflow-wrap: anywhere;
}

.contact-card small {
  margin-top: 8px;
  color: var(--muted);
  line-height: 1.5;
}

.steps {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
}

.steps span {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 78px;
  padding: 12px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.06);
  text-align: center;
  font-weight: 800;
  line-height: 1.35;
}

.footer {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 18px;
  align-items: center;
  padding: 28px clamp(18px, 4vw, 56px);
  color: var(--muted);
  font-size: 13px;
}

.footer p {
  flex: 1 1 520px;
  margin: 0;
}

.footer a {
  color: #8bd0ff;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer-links {
  display: flex;
  flex: 1 1 100%;
  flex-wrap: wrap;
  gap: 10px 14px;
  align-items: center;
  padding-top: 4px;
}

.footer-links strong {
  color: var(--text);
  font-size: 13px;
}

.footer-links a {
  display: inline-flex;
  min-height: 32px;
  align-items: center;
  border: 1px solid rgba(139, 208, 255, 0.22);
  border-radius: 6px;
  padding: 0 10px;
  background: rgba(139, 208, 255, 0.06);
  text-decoration: none;
}

.footer-links a:hover {
  border-color: rgba(139, 208, 255, 0.55);
  color: #dff3ff;
}

.footer-company {
  flex-basis: 100%;
  color: var(--muted);
}

@media (max-width: 1180px) {
  .hero {
    grid-template-columns: 1fr;
  }

  .hero-copy {
    min-height: 520px;
  }

  .hero-visual {
    min-height: 440px;
  }

  .device-grid,
  .install-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 780px) {
  .site-header {
    position: static;
    align-items: flex-start;
    flex-direction: column;
  }

  .brand {
    min-height: 34px;
  }

  .brand-logo {
    height: 26px;
    max-width: 132px;
  }

  .nav {
    justify-content: flex-start;
  }

  .hero-copy {
    min-height: auto;
  }

  .hero-visual {
    min-height: 300px;
  }

  .metrics,
  .risk-grid,
  .wireless-layout,
  .wireless-points,
  .install-grid,
  .device-grid,
  .cta,
  .contact,
  .contact-cards {
    grid-template-columns: 1fr;
  }

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

  .panel-copy h3,
  .panel-copy p {
    grid-column: auto;
  }

  .system-panel img {
    min-height: 330px;
  }

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

@media (max-width: 460px) {
  .nav a {
    width: calc(50% - 4px);
    text-align: center;
  }

  .hero-actions .button {
    width: 100%;
  }
}