:root {
  --black: #000000;
  --white: #ffffff;
  --gray-50: #f6f6f6;
  --gray-100: rgba(0, 0, 0, 0.08);
  --gray-200: rgba(0, 0, 0, 0.16);
  --gray-500: #6b6b6b;
  --gray-700: #424242;
  --accent: #000000;
  --accent-soft: rgba(0, 0, 0, 0.06);
  --shadow: none;
  --shadow-sm: none;
  --radius: 16px;
  --radius-sm: 10px;
  --container: 1200px;
}

/* Dark theme tokens (matches app _app-theme.scss) */
[data-theme='dark'] {
  color-scheme: dark;
  --black: #ffffff;
  --white: #1a1a1a;
  --gray-50: #242424;
  --gray-100: rgba(255, 255, 255, 0.12);
  --gray-200: rgba(255, 255, 255, 0.16);
  --gray-500: #ffffff;
  --gray-700: #ffffff;
  --accent: #ffffff;
  --accent-soft: rgba(255, 255, 255, 0.08);
  --shadow: none;
  --shadow-sm: none;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--white);
  color: var(--black);
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

button {
  font: inherit;
}

.material-icons {
  font-family: 'Material Icons';
  font-weight: normal;
  font-style: normal;
  line-height: 1;
  letter-spacing: normal;
  text-transform: none;
  white-space: nowrap;
  word-wrap: normal;
  direction: ltr;
  -webkit-font-smoothing: antialiased;
  -webkit-font-feature-settings: 'liga';
  font-feature-settings: 'liga';
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--white);
  background: color-mix(in srgb, var(--white) 92%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 0;
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  width: min(calc(100% - 48px), var(--container));
  margin: 0 auto;
  min-height: 72px;
}

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

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

.brand-logo-light {
  display: none;
}

.brand-logo-dark {
  display: block;
}

[data-theme='dark'] .brand-logo-dark {
  display: none;
}

[data-theme='dark'] .brand-logo-light {
  display: block;
}

.main-nav {
  display: flex;
  gap: 28px;
  margin-left: 16px;
}

.main-nav a {
  color: var(--black);
  font-weight: 500;
  font-size: 0.95rem;
  transition: opacity 0.15s ease;
}

.main-nav a:hover {
  opacity: 0.6;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-left: auto;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  white-space: nowrap;
  transition: transform 0.15s ease, background 0.15s ease, color 0.15s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--black);
  color: var(--white);
}

[data-theme='dark'] .btn-primary {
  background: #ffffff;
  color: #000000;
}

/* ---------- Theme switcher (shared component) ---------- */
.theme-switcher {
  --ts-shell-bg: var(--gray-50);
  --ts-shell-shadow: none;
  --ts-thumb-bg: var(--white);
  --ts-thumb-border: var(--gray-200);
  --ts-thumb-shadow: 0 1px 2px rgba(0, 0, 0, 0.06);
  --ts-focus-ring: rgba(0, 0, 0, 0.28);

  position: relative;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px;
  min-height: 42px;
  padding: 4px;
  border: 1px solid var(--gray-200);
  border-radius: 999px;
  background: var(--ts-shell-bg);
  box-shadow: var(--ts-shell-shadow);
}

[data-theme='dark'] .theme-switcher {
  --ts-shell-bg: rgba(255, 255, 255, 0.08);
  --ts-shell-shadow: none;
  --ts-thumb-bg: var(--white);
  --ts-thumb-border: rgba(255, 255, 255, 0.16);
  --ts-thumb-shadow: 0 1px 2px rgba(0, 0, 0, 0.24);
  --ts-focus-ring: rgba(255, 255, 255, 0.28);
}

.theme-switcher::before {
  content: '';
  position: absolute;
  top: 4px;
  left: 4px;
  width: calc(50% - 6px);
  height: calc(100% - 8px);
  border-radius: 999px;
  background: var(--ts-thumb-bg);
  border: 1px solid var(--ts-thumb-border);
  box-shadow: var(--ts-thumb-shadow);
  transition: transform 0.24s cubic-bezier(0.22, 1, 0.36, 1);
  pointer-events: none;
}

.theme-switcher--dark::before {
  transform: translateX(calc(100% + 4px));
}

.theme-switcher__option {
  position: relative;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 36px;
  min-height: 34px;
  padding: 0 10px;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--gray-500);
  cursor: pointer;
  transition: color 0.2s ease;
}

.theme-switcher__option.is-active,
.theme-switcher__option:hover:not(.is-active) {
  color: var(--black);
}

[data-theme='dark'] .theme-switcher__option.is-active,
[data-theme='dark'] .theme-switcher__option:hover:not(.is-active) {
  color: var(--black);
}

.theme-switcher__option:focus-visible {
  outline: 2px solid var(--ts-focus-ring);
  outline-offset: 2px;
}

.theme-switcher__icon {
  display: block;
  flex-shrink: 0;
}

/* ---------- Layout ---------- */
main {
  width: min(calc(100% - 48px), var(--container));
  margin: 0 auto;
  padding: 56px 0 88px;
}

.hero {
  text-align: center;
  margin-bottom: 48px;
}

.eyebrow {
  margin: 0 0 12px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gray-500);
}

.hero h1 {
  margin: 0;
  font-size: clamp(2.2rem, 4vw, 3.6rem);
  line-height: 1.05;
  letter-spacing: -0.04em;
}

.hero p {
  margin: 16px auto 0;
  max-width: 760px;
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--gray-500);
}

/* ---------- Cards ---------- */
.architecture-card,
.content-grid article,
.benefits {
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow-sm);
}

.architecture-card {
  padding: clamp(20px, 3vw, 34px);
}

.section-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 28px;
}

.section-head .eyebrow {
  margin-bottom: 6px;
}

.section-head h2,
.content-grid h2,
.benefits h2 {
  margin: 0;
  font-size: clamp(1.4rem, 2vw, 1.9rem);
  letter-spacing: -0.03em;
}

/* ---------- Architecture diagram ---------- */
.architecture-diagram {
  display: grid;
  grid-template-columns: 1.15fr 0.55fr 1fr 0.75fr 2.1fr 0.45fr 1.3fr;
  gap: 16px;
  align-items: center;
}

.diagram-column {
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm);
  padding: 16px;
  background: var(--gray-50);
}

.diagram-column h3 {
  margin: 0 0 14px;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--gray-500);
}

.site-card,
.apps article,
.cloud-modules article {
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm);
  background: var(--white);
}

.site-card {
  padding: 12px;
}

.site-card + .site-card {
  margin-top: 12px;
}

.site-card strong {
  display: block;
  margin-bottom: 10px;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.site-card small {
  display: block;
  margin-top: 8px;
  font-weight: 600;
  color: var(--gray-500);
}

.site-icons {
  display: flex;
  align-items: end;
  gap: 14px;
}

.factory-icon {
  position: relative;
  width: 48px;
  height: 32px;
  border: 2px solid var(--gray-700);
  border-top: 0;
}

.factory-icon::before {
  content: '';
  position: absolute;
  left: 4px;
  top: -20px;
  width: 8px;
  height: 20px;
  border: 2px solid var(--gray-700);
}

.factory-icon::after {
  content: '';
  position: absolute;
  inset: 17px 8px auto;
  height: 4px;
  background: repeating-linear-gradient(90deg, var(--gray-700), var(--gray-700) 4px, transparent 4px, transparent 10px);
}

.plc-icon {
  width: 52px;
  height: 36px;
  border: 2px solid var(--gray-700);
  background: repeating-linear-gradient(90deg, transparent 0 12px, var(--gray-700) 12px 14px);
}

.site-dots {
  text-align: center;
  font-size: 1.3rem;
  letter-spacing: 0.18em;
  color: var(--gray-500);
}

.diagram-arrow,
.diagram-arrow--apps {
  position: relative;
  min-height: 2px;
  border-top: 2px solid var(--accent);
}

.diagram-arrow::after,
.diagram-arrow--apps::after {
  content: '';
  position: absolute;
  right: -1px;
  top: -6px;
  border-left: 10px solid var(--accent);
  border-top: 5px solid transparent;
  border-bottom: 5px solid transparent;
}

.diagram-arrow span {
  position: absolute;
  left: 50%;
  top: 8px;
  transform: translateX(-50%);
  font-size: 0.74rem;
  font-weight: 600;
  white-space: nowrap;
  color: var(--gray-500);
}

.gateway-device {
  display: grid;
  gap: 8px;
  width: 78px;
  height: 110px;
  margin: 6px auto 16px;
  padding: 14px;
  border: 2px solid var(--gray-700);
  border-radius: 8px;
  transform: skewY(8deg);
}

.gateway-device span {
  border: 2px solid var(--gray-700);
  border-radius: 4px;
}

.gateway ul,
.content-grid ul,
.content-grid ol {
  margin: 0;
  padding-left: 20px;
}

.gateway li {
  margin: 8px 0;
  font-size: 0.88rem;
}

.diagram-link {
  display: grid;
  gap: 5px;
  justify-items: center;
  text-align: center;
}

.lock {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 50%;
  color: var(--accent);
}

.lock .material-icons {
  font-size: 22px;
}

.diagram-link strong {
  color: var(--accent);
}

.diagram-link small {
  font-weight: 600;
  color: var(--gray-500);
}

.cloud {
  padding: 22px;
}

.cloud h3 {
  text-align: center;
}

.cloud-modules {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
}

.cloud-modules article {
  display: grid;
  gap: 8px;
  justify-items: center;
  min-height: 96px;
  padding: 14px 8px;
  text-align: center;
  font-weight: 600;
  font-size: 0.86rem;
}

.module-icon {
  font-size: 26px;
  color: var(--black);
}

.apps {
  display: grid;
  gap: 12px;
}

.apps article {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px;
  font-weight: 600;
  font-size: 0.9rem;
}

.app-icon {
  flex-shrink: 0;
  font-size: 22px;
  color: var(--black);
}

.apps small {
  font-weight: 400;
  color: var(--gray-500);
}

/* ---------- Content grid & benefits ---------- */
.content-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  margin-top: 24px;
}

.content-grid article,
.benefits {
  padding: 28px;
}

.content-grid li {
  margin: 12px 0;
}

.benefits {
  margin-top: 24px;
}

.benefit-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 14px;
  margin-top: 22px;
}

.benefit-grid article {
  display: grid;
  gap: 6px;
  padding: 18px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm);
  background: var(--gray-50);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.benefit-grid .benefit-icon {
  font-size: 28px;
  color: var(--black);
  margin-bottom: 4px;
}

.benefit-grid article:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.benefit-grid strong {
  font-size: 0.95rem;
}

.benefit-grid span {
  font-size: 0.82rem;
  color: var(--gray-500);
}

/* ---------- Mobile menu toggle ---------- */
.mobile-menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--black);
  cursor: pointer;
  transition: background 0.15s ease;
}

.mobile-menu-toggle:hover {
  background: var(--accent-soft);
}

.mobile-menu-toggle svg {
  display: block;
}

/* ---------- Responsive ---------- */
@media (max-width: 980px) {
  .architecture-diagram,
  .content-grid,
  .benefit-grid {
    grid-template-columns: 1fr;
  }

  .diagram-arrow,
  .diagram-arrow--apps {
    min-height: 44px;
    width: 2px;
    margin: 0 auto;
    border-top: 0;
    border-left: 2px solid var(--accent);
  }

  .diagram-arrow::after,
  .diagram-arrow--apps::after {
    right: auto;
    top: auto;
    bottom: -1px;
    left: -6px;
    border-top: 10px solid var(--accent);
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-bottom: 0;
  }

  .diagram-arrow span {
    left: 16px;
    top: 10px;
    transform: none;
  }

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

@media (max-width: 720px) {
  .mobile-menu-toggle {
    display: inline-flex;
  }

  .main-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    margin: 0;
    padding: 12px 24px 16px;
    background: var(--white);
    border-bottom: 0;
  }

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

  .main-nav a {
    display: block;
    padding: 12px 0;
  }

  .header-inner {
    flex-wrap: wrap;
  }
}

@media (max-width: 640px) {
  .header-inner {
    gap: 10px;
    width: min(calc(100% - 32px), var(--container));
    min-height: 56px;
  }

  .brand-logo {
    height: 22px;
  }

  .btn-primary {
    min-height: 38px;
    padding: 0 14px;
    font-size: 0.85rem;
  }

  .theme-switcher {
    min-height: 36px;
    padding: 3px;
  }

  .theme-switcher__option {
    min-width: 30px;
    min-height: 28px;
    padding: 0 8px;
  }

  .theme-switcher__icon {
    width: 16px;
    height: 16px;
  }

  main {
    width: min(calc(100% - 32px), var(--container));
    padding: 32px 0 56px;
  }

  .hero {
    margin-bottom: 28px;
  }

  .hero h1 {
    font-size: 1.75rem;
    line-height: 1.12;
    letter-spacing: -0.03em;
  }

  .hero p {
    margin-top: 12px;
    font-size: 0.95rem;
  }

  .eyebrow {
    font-size: 0.72rem;
    margin-bottom: 8px;
  }

  .architecture-card {
    padding: 16px;
  }

  .section-head {
    flex-direction: column;
    align-items: start;
    gap: 8px;
    margin-bottom: 20px;
  }

  .section-head h2,
  .content-grid h2,
  .benefits h2 {
    font-size: 1.2rem;
  }

  .diagram-column {
    padding: 12px;
  }

  .site-card {
    padding: 10px;
  }

  .site-card + .site-card {
    margin-top: 8px;
  }

  .factory-icon {
    width: 36px;
    height: 24px;
  }

  .factory-icon::before {
    top: -16px;
    width: 6px;
    height: 16px;
  }

  .plc-icon {
    width: 40px;
    height: 28px;
  }

  .gateway-device {
    width: 60px;
    height: 84px;
    padding: 10px;
    margin: 4px auto 12px;
  }

  .gateway li {
    font-size: 0.82rem;
    margin: 6px 0;
  }

  .cloud {
    padding: 14px;
  }

  .cloud-modules {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .cloud-modules article {
    min-height: auto;
    padding: 12px 10px;
    grid-template-columns: auto 1fr;
    grid-template-rows: auto;
    justify-items: start;
    text-align: left;
    gap: 8px;
  }

  .apps article {
    padding: 10px;
    font-size: 0.84rem;
    gap: 10px;
  }

  .diagram-link {
    gap: 4px;
  }

  .lock {
    width: 36px;
    height: 36px;
  }

  .lock .material-icons {
    font-size: 18px;
  }

  .diagram-link strong {
    font-size: 0.82rem;
  }

  .diagram-link small {
    font-size: 0.74rem;
  }

  .content-grid {
    gap: 14px;
    margin-top: 16px;
  }

  .content-grid article,
  .benefits {
    padding: 18px;
  }

  .content-grid li {
    margin: 8px 0;
    font-size: 0.9rem;
  }

  .benefits {
    margin-top: 16px;
  }

  .benefit-grid {
    gap: 10px;
    margin-top: 16px;
  }

  .benefit-grid article {
    padding: 14px;
    grid-template-columns: auto 1fr;
    grid-template-rows: auto auto;
    column-gap: 12px;
    row-gap: 2px;
  }

  .benefit-grid .benefit-icon {
    grid-row: 1 / -1;
    font-size: 24px;
    margin-bottom: 0;
    align-self: center;
  }

  .benefit-grid strong {
    font-size: 0.88rem;
  }

  .benefit-grid span {
    font-size: 0.78rem;
  }
}

/* Extra small phones (< 380px) */
@media (max-width: 380px) {
  .header-inner {
    width: min(calc(100% - 24px), var(--container));
  }

  main {
    width: min(calc(100% - 24px), var(--container));
  }

  .hero h1 {
    font-size: 1.5rem;
  }

  .architecture-card {
    padding: 12px;
  }

  .content-grid article,
  .benefits {
    padding: 14px;
  }

  .btn-primary {
    min-height: 36px;
    padding: 0 12px;
    font-size: 0.82rem;
  }
}