/* ── Mobile navigation ── */
html { scroll-behavior: smooth; }
body { overflow-x: hidden; }
body.nav-lock {
  overflow: hidden !important;
  position: relative;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  background: transparent;
  border: 1.5px solid #DDE8F2;
  border-radius: 8px;
  cursor: pointer;
  flex-shrink: 0;
  z-index: 110;
}
.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: #0F3460;
  border-radius: 2px;
  transition: transform 0.25s, opacity 0.25s;
}
nav.nav-open .nav-toggle span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
nav.nav-open .nav-toggle span:nth-child(2) { opacity: 0; }
nav.nav-open .nav-toggle span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-menu .nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

@media (min-width: 901px) {
  .nav-toggle { display: none !important; }

  nav,
  #site-nav {
    overflow: visible !important;
  }

  .nav-menu,
  #nav-menu {
    position: static !important;
    transform: none !important;
    background: transparent !important;
    padding: 0 !important;
    border: none !important;
    overflow: visible !important;
    height: 100% !important;
    width: auto !important;
    visibility: visible !important;
    pointer-events: auto !important;
    display: flex !important;
    flex-direction: row !important;
    align-items: center !important;
    gap: 2rem !important;
  }

  .nav-links,
  .nav-menu .nav-links {
    height: 100%;
    align-items: stretch;
    overflow: visible;
  }

  .nav-links > li {
    display: flex;
    align-items: center;
  }
}

/* ── Tablet & mobile (≤900px) ── */
@media (max-width: 900px) {
  nav,
  #site-nav {
    padding: 0 4%;
    height: 64px;
    overflow: visible !important;
    /* backdrop-filter creates a containing block and traps position:fixed children */
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
    transform: none !important;
    filter: none !important;
  }

  .nav-toggle { display: flex; }

  .nav-menu,
  #nav-menu {
    position: fixed !important;
    top: 64px !important;
    left: 0 !important;
    right: 0 !important;
    bottom: 0 !important;
    width: 100% !important;
    height: calc(100vh - 64px) !important;
    height: calc(100dvh - 64px) !important;
    max-height: none !important;
    display: flex !important;
    flex-direction: column !important;
    align-items: stretch !important;
    justify-content: flex-start !important;
    gap: 0 !important;
    background: #fff !important;
    backdrop-filter: blur(12px);
    padding: 1.25rem 5% 2rem !important;
    transform: translateX(100%) !important;
    transition: transform 0.3s ease, visibility 0.3s ease;
    overflow-x: hidden !important;
    overflow-y: auto !important;
    z-index: 200 !important;
    border-top: 1px solid #DDE8F2;
    box-shadow: none;
    visibility: hidden;
    pointer-events: none;
  }

  nav.nav-open .nav-menu,
  #site-nav.nav-open #nav-menu {
    transform: translateX(0) !important;
    visibility: visible !important;
    pointer-events: auto !important;
  }

  .nav-links,
  .nav-menu .nav-links {
    display: flex !important;
    flex-direction: column !important;
    gap: 0 !important;
    width: 100% !important;
    list-style: none !important;
    margin: 0 !important;
    padding: 0 !important;
    flex: 0 0 auto !important;
  }

  .nav-links li {
    display: block !important;
    border-bottom: 1px solid #DDE8F2;
    width: 100%;
  }

  .nav-links a {
    display: block !important;
    padding: 1rem 0 !important;
    font-size: 1.05rem !important;
    color: #1C2B3A !important;
    visibility: visible !important;
  }

  nav .nav-cta,
  .nav-menu .nav-cta {
    margin-top: 1.25rem !important;
    text-align: center;
    padding: 0.85rem 1.5rem !important;
    width: 100% !important;
    display: block !important;
    flex-shrink: 0;
  }

  .logo {
    font-size: 1.15rem !important;
    gap: 8px !important;
    min-width: 0;
  }

  .logo img {
    width: 36px !important;
    height: 36px !important;
  }

  /* Page heroes */
  .page-hero {
    padding: 110px 5% 50px !important;
  }

  .page-hero h1 {
    font-size: clamp(1.75rem, 6vw, 2.4rem) !important;
  }

  .page-hero p {
    font-size: 0.95rem !important;
  }

  /* Sections */
  section {
    padding: 50px 5% !important;
  }

  .section-header {
    margin-bottom: 2rem !important;
  }

  .section-title {
    font-size: clamp(1.4rem, 5vw, 1.9rem) !important;
  }

  /* Homepage hero */
  .hero {
    min-height: auto !important;
    padding: 100px 5% 60px !important;
  }

  .hero-visual {
    display: flex;
    justify-content: center;
  }

  .vitals-card {
    width: 100%;
    max-width: 380px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn-primary,
  .hero-actions .btn-ghost {
    justify-content: center;
    text-align: center;
  }

  /* Grids */
  .steps-grid,
  .flow-grid,
  .services-grid,
  .sensors-grid,
  .pipeline-grid,
  .escalation-grid,
  .features-grid,
  .detail-grid,
  .benefits-grid,
  .rpm-grid,
  .cta-cards {
    grid-template-columns: 1fr !important;
  }

  .monitor-layout,
  .activity-layout,
  .consult-layout {
    grid-template-columns: 1fr !important;
    gap: 2rem !important;
    padding-left: 5% !important;
    padding-right: 5% !important;
  }

  .activity-stats {
    grid-template-columns: 1fr 1fr !important;
  }

  .vitals-grid {
    grid-template-columns: repeat(2, 1fr) !important;
  }

  .trust-grid {
    grid-template-columns: 1fr 1fr !important;
  }

  .stats-grid {
    grid-template-columns: 1fr 1fr !important;
    gap: 1.5rem !important;
  }

  /* Device profiles */
  .device-header {
    grid-template-columns: 1fr !important;
    text-align: center;
    padding: 1.5rem !important;
  }

  .device-icon { margin: 0 auto; }

  .device-badges {
    justify-content: center !important;
  }

  .device-body {
    grid-template-columns: 1fr !important;
  }

  .device-col {
    border-right: none !important;
    border-bottom: 1px solid #DDE8F2;
    padding: 1.5rem !important;
  }

  .device-col:last-child { border-bottom: none; }

  .device-footer {
    flex-direction: column;
    align-items: stretch;
    padding: 1.25rem 1.5rem !important;
  }

  .device-footer .select-btn,
  .device-footer .pricing-note {
    width: 100%;
    max-width: none;
  }

  .devices-section {
    padding: 50px 4% 70px !important;
  }

  /* Forms */
  .form-row {
    grid-template-columns: 1fr !important;
  }

  .form-card {
    padding: 1.75rem !important;
  }

  /* CTA strips */
  .cta-strip {
    padding: 60px 5% !important;
  }

  .cta-strip .btn-primary,
  .cta-strip .btn-ghost {
    width: 100%;
    justify-content: center;
    margin-left: 0 !important;
    margin-top: 0.5rem;
  }

  .cta-section {
    padding: 70px 5% !important;
  }

  /* Footer */
  .footer-grid {
    grid-template-columns: 1fr 1fr !important;
    gap: 2rem !important;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
    gap: 0.75rem;
  }

  /* Touch: disable hover zoom on sensors */
  .zoom-overlay {
    display: none !important;
  }

  .step-arrow { display: none !important; }
}

/* ── Small phones (≤480px) ── */
@media (max-width: 480px) {
  nav { padding: 0 3.5%; }

  .logo-text {
    font-size: 1rem !important;
  }

  .logo img {
    width: 32px !important;
    height: 32px !important;
  }

  .page-hero {
    padding: 96px 4% 40px !important;
  }

  section {
    padding: 40px 4% !important;
  }

  .hero {
    padding: 88px 4% 48px !important;
  }

  .hero h1 {
    font-size: 2rem !important;
  }

  .hero-eyebrow {
    font-size: 0.7rem !important;
  }

  .activity-stats,
  .vitals-mini-grid,
  .vitals-grid,
  .stats-grid,
  .trust-grid {
    grid-template-columns: 1fr !important;
  }

  .footer-grid {
    grid-template-columns: 1fr !important;
  }

  .device-product {
    font-size: 1.25rem !important;
  }

  .form-card h2 {
    font-size: 1.25rem !important;
  }

  .stat-num {
    font-size: 1.75rem !important;
  }

  .cta-cards .cta-card {
    min-width: 0 !important;
    width: 100%;
  }

  .monitor-dashboard,
  .form-card {
    border-radius: 14px !important;
  }

  .pipe-step,
  .flow-card,
  .service-card,
  .sensor-card {
    padding: 1.5rem !important;
  }
}

/* ── Devices nav submenu ── */
.nav-has-submenu {
  position: relative;
}

.nav-has-submenu > .nav-parent {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.nav-caret {
  font-size: 0.65rem;
  line-height: 1;
  transition: transform 0.2s ease;
}

.nav-submenu {
  list-style: none;
  margin: 0;
  padding: 0;
}

@media (min-width: 901px) {
  .nav-has-submenu {
    height: 100%;
  }

  .nav-has-submenu > .nav-parent {
    height: 100%;
    padding: 0 0.15rem;
  }

  .nav-has-submenu:hover .nav-caret,
  .nav-has-submenu:focus-within .nav-caret,
  .nav-has-submenu.open .nav-caret {
    transform: rotate(180deg);
  }

  .nav-submenu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    min-width: 250px;
    background: #fff;
    border: 1.5px solid #DDE8F2;
    border-radius: 12px;
    box-shadow: 0 12px 32px rgba(13, 148, 136, 0.12);
    padding: 0.45rem 0;
    margin-top: 0;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.15s ease, visibility 0.15s ease;
    z-index: 300;
  }

  /* Invisible bridge so the cursor never leaves hover between link and menu */
  .nav-submenu::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: -16px;
    height: 16px;
  }

  .nav-has-submenu:hover .nav-submenu,
  .nav-has-submenu:focus-within .nav-submenu {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }

  .nav-submenu li {
    border-bottom: none;
    display: block;
  }

  .nav-submenu a {
    display: block;
    padding: 0.6rem 1.25rem;
    font-size: 0.85rem;
    color: #6B7D8E;
    text-decoration: none;
    white-space: nowrap;
  }

  .nav-submenu a:hover,
  .nav-submenu a.active {
    background: #E6FAF8;
    color: #0D9488;
  }
}

@media (max-width: 900px) {
  .nav-has-submenu > .nav-parent {
    width: 100%;
    justify-content: space-between;
  }

  .nav-has-submenu.open .nav-caret {
    transform: rotate(180deg);
  }

  .nav-submenu {
    display: none;
    padding: 0 0 0.75rem 1rem;
    margin-bottom: 0.25rem;
    border-left: 2px solid #E6FAF8;
  }

  .nav-has-submenu.open .nav-submenu {
    display: block;
  }

  .nav-submenu li {
    border-bottom: none;
  }

  .nav-submenu a {
    display: block !important;
    padding: 0.65rem 0 !important;
    font-size: 0.95rem !important;
    color: #6B7D8E !important;
  }

  .nav-submenu a.active {
    color: #0D9488 !important;
    font-weight: 600;
  }
}