/* =========================================================
   ZK Engineering — Design System
   Modern professional website for an engineering consultancy
   ========================================================= */

/* === DESIGN TOKENS === */
:root {
  --primary:        #1B3D7A;
  --primary-dark:   #122D5E;
  --primary-light:  #2563EB;
  --blue-400:       #60A5FA;
  --blue-100:       #DBEAFE;
  --blue-50:        #EFF6FF;

  --text-dark:      #0F172A;
  --text:           #1E293B;
  --text-muted:     #475569;
  --text-light:     #94A3B8;

  --bg:             #F8FAFC;
  --bg-subtle:      #F1F5F9;
  --card-bg:        #FFFFFF;
  --border:         #E2E8F0;
  --border-light:   #F1F5F9;
  --white:          #FFFFFF;
  --success:        #059669;

  --shadow-xs:  0 1px 2px rgba(15,23,42,0.04);
  --shadow-sm:  0 1px 3px rgba(15,23,42,0.06), 0 1px 2px rgba(15,23,42,0.04);
  --shadow-md:  0 4px 16px rgba(15,23,42,0.08);
  --shadow-lg:  0 10px 40px rgba(15,23,42,0.10), 0 4px 8px rgba(15,23,42,0.05);
  --shadow-blue: 0 4px 24px rgba(37,99,235,0.22);

  --radius-sm:  8px;
  --radius:     12px;
  --radius-lg:  18px;
  --radius-xl:  24px;

  --transition:      0.25s ease;
  --transition-slow: 0.4s ease;

  --nav-height:    72px;
  --container-max: 1200px;
  --container-pad: clamp(20px, 4vw, 48px);
}

/* === RESET & BASE === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  min-height: 100svh;
}

img, svg { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { font-family: inherit; }

/* === LANGUAGE SYSTEM === */
html[data-lang="nl"] .lang-fr { display: none !important; }
html[data-lang="fr"] .lang-nl { display: none !important; }

/* === TYPOGRAPHY === */
h1 { font-size: clamp(2rem, 5vw, 3.25rem); font-weight: 800; line-height: 1.13; color: var(--text-dark); letter-spacing: -0.025em; overflow-wrap: break-word; }
h2 { font-size: clamp(1.625rem, 3.5vw, 2.375rem); font-weight: 700; line-height: 1.2; color: var(--text-dark); letter-spacing: -0.015em; }
h3 { font-size: clamp(1.1rem, 2.5vw, 1.375rem); font-weight: 600; line-height: 1.3; color: var(--text-dark); }
h4 { font-size: 1rem; font-weight: 600; line-height: 1.4; color: var(--text-dark); }
p  { line-height: 1.75; color: var(--text-muted); }

/* === LAYOUT === */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
}
.section       { padding: clamp(64px, 8vw, 104px) 0; }
.section-alt   { background: var(--bg-subtle); }
.section-white { background: var(--white); }
.text-center   { text-align: center; }

/* === SECTION HEADER === */
.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 60px;
}
.section-eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--primary-light);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 14px;
}
.section-header h2  { margin-bottom: 16px; }
.section-header p   { font-size: 1rem; }

/* === NAVBAR === */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: rgba(255,255,255,0.93);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: var(--transition);
}
.navbar.scrolled {
  border-bottom-color: var(--border);
  box-shadow: var(--shadow-sm);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
/* Logo */
.nav-logo {
  display: flex;
  align-items: baseline;
  gap: 3px;
  text-decoration: none;
  flex-shrink: 0;
  transition: opacity var(--transition);
}
.nav-logo:hover { opacity: 0.82; }
.logo-zk  { font-size: 1.625rem; font-weight: 900; color: var(--primary); letter-spacing: -0.04em; line-height: 1; }
.logo-eng { font-size: 0.95rem; font-weight: 400; color: var(--text-muted); letter-spacing: 0.01em; margin-left: 3px; padding-bottom: 1px; }

/* Nav links */
.nav-links {
  display: flex;
  align-items: center;
  gap: 2px;
  margin: 0 24px;
}
.nav-links a {
  padding: 8px 13px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: var(--transition);
  white-space: nowrap;
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
  background: var(--blue-50);
}

/* Services dropdown */
.nav-dropdown { position: relative; }
.nav-dropdown-toggle {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  user-select: none;
  padding: 8px 13px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: var(--transition);
  white-space: nowrap;
}
.nav-dropdown-toggle:hover,
.nav-dropdown-toggle.active {
  color: var(--primary);
  background: var(--blue-50);
}
.nav-dropdown-toggle svg { width: 14px; height: 14px; transition: transform var(--transition); }
.nav-dropdown.open .nav-dropdown-toggle svg { transform: rotate(180deg); }
.nav-dropdown.open .nav-dropdown-toggle,
.nav-dropdown:hover .nav-dropdown-toggle { color: var(--primary); background: var(--blue-50); }
/* When dropdown is open, suppress active highlight on sibling nav links */
.nav-links:has(.nav-dropdown.open) > a.active {
  color: var(--text-muted);
  background: transparent;
}

.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%) translateY(-8px);
  min-width: 256px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: 8px;
  opacity: 0;
  pointer-events: none;
  transition: var(--transition);
  z-index: 200;
}
.nav-dropdown.open .nav-dropdown-menu,
.nav-dropdown:hover .nav-dropdown-menu {
  opacity: 1;
  pointer-events: auto;
  transform: translateX(-50%) translateY(0);
}
.nav-dropdown-menu a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text);
  transition: var(--transition);
}
.nav-dropdown-menu a:hover {
  background: var(--blue-50);
  color: var(--primary);
}
.dd-icon {
  width: 34px; height: 34px;
  background: var(--blue-50);
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
  transition: var(--transition);
}
.dd-icon svg { width: 16px; height: 16px; color: var(--primary-light); }
.nav-dropdown-menu a:hover .dd-icon { background: var(--blue-100); }

/* Nav right */
.nav-right { display: flex; align-items: center; gap: 10px; }

/* Language toggle */
.lang-toggle {
  display: flex;
  align-items: center;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 3px;
  gap: 2px;
}
.lang-btn {
  padding: 4px 11px;
  border-radius: 16px;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--text-light);
  cursor: pointer;
  transition: var(--transition);
  background: none;
  border: none;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.lang-btn.active {
  background: var(--white);
  color: var(--primary);
  box-shadow: var(--shadow-xs);
}

/* Nav CTA button */
.btn-nav {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 20px;
  background: var(--primary);
  color: var(--white);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  transition: var(--transition);
  white-space: nowrap;
  border: none;
  cursor: pointer;
}
.btn-nav:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-blue);
}

/* Hamburger */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 10px 8px;
  cursor: pointer;
  background: none;
  border: none;
}
.nav-hamburger span {
  display: block;
  width: 22px; height: 2px;
  background: var(--text-dark);
  border-radius: 2px;
  transition: var(--transition);
}
.nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile menu */
.nav-mobile {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0; right: 0; bottom: 0;
  background: var(--white);
  padding: 16px var(--container-pad) 32px;
  overflow-y: auto;
  z-index: 999;
  flex-direction: column;
}
.nav-mobile.open { display: flex; }
.nav-mobile-section { margin-bottom: 8px; }
.nav-mobile-label {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-light);
  padding: 16px 12px 8px;
}
.nav-mobile a {
  display: block;
  padding: 13px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text);
  transition: var(--transition);
}
.nav-mobile a:hover,
.nav-mobile a.active { color: var(--primary); background: var(--blue-50); }
.nav-mobile a.sub { padding-left: 28px; font-size: 0.875rem; color: var(--text-muted); }
.nav-mobile-footer {
  margin-top: auto;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* === BUTTONS === */
.btn-primary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 28px;
  background: var(--primary);
  color: var(--white);
  border: none; border-radius: var(--radius-sm);
  font-size: 0.975rem; font-weight: 600;
  cursor: pointer; transition: var(--transition);
  text-decoration: none;
}
.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-blue);
}
.btn-secondary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 28px;
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
  border-radius: var(--radius-sm);
  font-size: 0.975rem; font-weight: 600;
  cursor: pointer; transition: var(--transition);
  text-decoration: none;
}
.btn-secondary:hover {
  background: var(--blue-50);
  transform: translateY(-2px);
}
.btn-outline {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 22px;
  background: transparent;
  color: var(--text-muted);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem; font-weight: 500;
  cursor: pointer; transition: var(--transition);
  text-decoration: none;
}
.btn-outline:hover {
  color: var(--primary);
  border-color: var(--primary-light);
  background: var(--blue-50);
}
.btn-white {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 28px;
  background: var(--white);
  color: var(--primary);
  border: none; border-radius: var(--radius-sm);
  font-size: 0.975rem; font-weight: 700;
  cursor: pointer; transition: var(--transition);
  text-decoration: none;
}
.btn-white:hover {
  background: var(--blue-50);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(0,0,0,0.18);
}
.btn-white-outline {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 28px;
  background: transparent;
  color: var(--white);
  border: 2px solid rgba(255,255,255,0.45);
  border-radius: var(--radius-sm);
  font-size: 0.975rem; font-weight: 600;
  cursor: pointer; transition: var(--transition);
  text-decoration: none;
}
.btn-white-outline:hover {
  border-color: var(--white);
  background: rgba(255,255,255,0.12);
  transform: translateY(-2px);
}
.cta-btns { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }

/* === HERO (home) === */
.hero {
  padding-top: var(--nav-height);
  min-height: 100svh;
  display: flex; align-items: center;
  position: relative; overflow: hidden;
  background: linear-gradient(150deg, #F8FAFF 0%, #EEF4FF 45%, #E2EEFF 100%);
}
.hero-bg {
  position: absolute; inset: 0;
  pointer-events: none; overflow: hidden;
}
.hero-bg::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(37,99,235,0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(37,99,235,0.055) 1px, transparent 1px);
  background-size: 52px 52px;
}
.hero-shape {
  position: absolute;
  right: -8%;
  top: 8%;
  width: 54%;
  height: 84%;
  background: linear-gradient(135deg, rgba(37,99,235,0.07) 0%, rgba(96,165,250,0.03) 100%);
  clip-path: polygon(18% 0%, 100% 0%, 82% 100%, 0% 100%);
}
.hero-shape-2 {
  position: absolute;
  right: 4%;
  bottom: -10%;
  width: 30%;
  height: 50%;
  background: linear-gradient(135deg, rgba(37,99,235,0.04) 0%, transparent 100%);
  clip-path: polygon(0% 0%, 100% 20%, 80% 100%, 0% 80%);
  border-radius: 4px;
}
.hero-inner {
  position: relative; z-index: 1;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 48px;
  align-items: center;
  width: 100%;
  padding-top: clamp(40px, 6vw, 80px);
  padding-bottom: clamp(40px, 6vw, 80px);
}
.hero-content { max-width: 660px; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 14px;
  background: var(--blue-50);
  border: 1px solid var(--blue-100);
  border-radius: 20px;
  font-size: 0.75rem; font-weight: 700;
  color: var(--primary-light);
  letter-spacing: 0.08em; text-transform: uppercase;
  margin-bottom: 24px;
}
.hero-badge svg { width: 14px; height: 14px; }
.hero h1 { margin-bottom: 20px; }
.hero h1 em { font-style: normal; color: var(--primary-light); }
.hero-lead {
  font-size: clamp(0.975rem, 2vw, 1.1rem);
  color: var(--text-muted);
  margin-bottom: 36px;
  max-width: 540px;
}
.hero-ctas { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 52px; }
.hero-trust {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}
.hero-trust-item {
  display: flex; align-items: center; gap: 8px;
}
.hero-trust-item svg { width: 16px; height: 16px; color: var(--primary-light); flex-shrink: 0; }
.hero-trust-item span { font-size: 0.8rem; font-weight: 600; color: var(--text-muted); }

/* Hero visual (right side) */
/* Hero visual (right side) */
.hero-visual {
  flex-shrink: 0;
}

/* 2×2 domain tiles grid — square cards */
.hero-domains-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.hero-domain-tile {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  gap: 0;
  padding: 28px 26px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--white);
  text-decoration: none;
  text-align: center;
  aspect-ratio: 1 / 1;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  position: relative;
  overflow: hidden;
}
.hero-domain-tile::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--blue-50) 0%, transparent 60%);
  opacity: 0;
  transition: opacity 0.2s ease;
}
.hero-domain-tile:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(37,99,235,0.25);
}
.hero-domain-tile:hover::before { opacity: 1; }

/* All icons use the site's blue palette — differentiated by shade */
.hdt-icon {
  width: 52px; height: 52px;
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
  position: relative;
}
.tile-heat   .hdt-icon { background: rgba(37,99,235,0.08);  color: #1D4ED8; }
.tile-air    .hdt-icon { background: rgba(37,99,235,0.13);  color: var(--primary); }
.tile-peb    .hdt-icon { background: rgba(30,64,175,0.10);  color: #1E40AF; }
.tile-energy .hdt-icon { background: rgba(59,130,246,0.12); color: #3B82F6; }
.hdt-icon svg { width: 26px; height: 26px; position: relative; }

.hdt-body {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  flex: 1;
  position: relative;
  width: 100%;
}
.hdt-body strong {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
  display: block;
}
.hdt-body span {
  font-size: 0.875rem;
  color: var(--text-muted);
  display: block;
}

.hdt-arrow { display: none; }

/* === PAGE HEADER (sub-pages) === */
.page-header {
  padding-top: var(--nav-height);
  background: linear-gradient(150deg, #F8FAFF 0%, #EEF4FF 55%, #E5EEFF 100%);
  position: relative; overflow: hidden;
}
.page-header-bg {
  position: absolute; inset: 0; pointer-events: none;
}
.page-header-bg::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(37,99,235,0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(37,99,235,0.045) 1px, transparent 1px);
  background-size: 52px 52px;
}
.page-header-bg::after {
  content: '';
  position: absolute;
  right: -5%; top: 5%;
  width: 45%; height: 90%;
  background: linear-gradient(135deg, rgba(37,99,235,0.06) 0%, transparent 100%);
  clip-path: polygon(20% 0%, 100% 0%, 80% 100%, 0% 100%);
}
.page-header-inner {
  position: relative; z-index: 1;
  padding-top: 56px;
  padding-bottom: 80px;
}
.page-header-breadcrumb {
  display: flex; align-items: center; gap: 8px;
  margin-bottom: 20px;
}
.page-header-breadcrumb a,
.page-header-breadcrumb span {
  font-size: 0.8rem;
  color: var(--text-light);
  font-weight: 500;
  transition: color var(--transition);
}
.page-header-breadcrumb a:hover { color: var(--primary-light); }
.page-header-breadcrumb .sep { color: var(--border); }
.page-header-breadcrumb .current { color: var(--primary-light); font-weight: 600; }
.page-header h1 { margin-bottom: 18px; }
.page-header-lead {
  font-size: clamp(0.975rem, 2vw, 1.1rem);
  color: var(--text-muted);
  max-width: 600px;
  line-height: 1.75;
}

/* Wave divider */
.wave-divider { display: block; width: 100%; overflow: hidden; line-height: 0; }
.wave-divider svg { display: block; width: 100%; }

/* === SERVICE CARDS GRID === */
.services-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.service-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: var(--transition);
  position: relative; overflow: hidden;
  display: flex; flex-direction: column;
}
.service-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--primary-light));
  transform: scaleX(0);
  transition: var(--transition);
  transform-origin: left;
}
.service-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--blue-100);
}
.service-card:hover::before { transform: scaleX(1); }
.service-card-icon {
  width: 54px; height: 54px;
  background: var(--blue-50);
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 20px;
  transition: var(--transition);
}
.service-card:hover .service-card-icon { background: var(--blue-100); }
.service-card-icon svg { width: 26px; height: 26px; color: var(--primary-light); }
.service-card h3 { margin-bottom: 12px; }
.service-card > p { font-size: 0.9rem; margin-bottom: 20px; flex-grow: 1; }
.service-card ul { margin-bottom: 24px; }
.service-card ul li {
  font-size: 0.85rem; color: var(--text-muted);
  padding: 5px 0 5px 16px;
  position: relative;
  border-bottom: 1px solid var(--border-light);
}
.service-card ul li:last-child { border-bottom: none; }
.service-card ul li::before {
  content: '';
  position: absolute; left: 0; top: 50%; transform: translateY(-50%);
  width: 6px; height: 6px;
  background: var(--primary-light);
  border-radius: 50%;
}

/* === INFO CARDS === */
.info-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}
.info-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  transition: var(--transition);
  display: flex; flex-direction: column;
}
.info-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
  border-color: var(--blue-100);
}
.info-card-icon {
  width: 60px; height: 60px;
  background: linear-gradient(135deg, var(--blue-50), var(--blue-100));
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 24px;
}
.info-card-icon svg { width: 30px; height: 30px; color: var(--primary); }
.info-card h3 { margin-bottom: 12px; }
.info-card > p { font-size: 0.9rem; line-height: 1.72; margin-bottom: 20px; flex-grow: 1; }
.info-card ul { margin-bottom: 24px; }
.info-card ul li {
  font-size: 0.85rem; color: var(--text-muted);
  padding: 7px 0 7px 20px;
  position: relative;
  border-bottom: 1px solid var(--border-light);
}
.info-card ul li:last-child { border-bottom: none; }
.info-card ul li::before {
  content: '→';
  position: absolute; left: 0;
  color: var(--primary-light);
  font-size: 0.8rem;
  line-height: 1.75;
}

/* === TECHNIQUE ITEMS === */
.technique-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 32px;
  align-items: start;
  padding: 40px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  margin-bottom: 24px;
  transition: var(--transition);
}
.technique-item:last-child { margin-bottom: 0; }
.technique-item:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--blue-100);
}
.technique-icon-wrap {
  width: 68px; height: 68px;
  background: linear-gradient(135deg, var(--blue-50), var(--blue-100));
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
}
.technique-icon-wrap svg { width: 34px; height: 34px; color: var(--primary); }
.technique-content h3 { margin-bottom: 10px; }
.technique-content > p { font-size: 0.925rem; margin-bottom: 18px; }
.technique-content ul {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 6px 24px;
}
.technique-content ul li {
  font-size: 0.85rem; color: var(--text-muted);
  padding: 5px 0 5px 16px;
  position: relative;
}
.technique-content ul li::before {
  content: '';
  position: absolute; left: 0; top: 50%; transform: translateY(-50%);
  width: 6px; height: 6px;
  background: var(--primary-light);
  border-radius: 50%;
}

/* === FEATURE ROW (2-col alternating) === */
.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 72px;
  align-items: center;
  margin-bottom: 80px;
}
.feature-row:last-child { margin-bottom: 0; }
.feature-row.reverse .feature-visual { order: 1; }
.feature-row.reverse .feature-content { order: -1; }

.feature-visual {
  background: linear-gradient(135deg, var(--blue-50) 0%, #D9EAFF 100%);
  border-radius: var(--radius-xl);
  padding: 48px 40px;
  display: flex; align-items: center; justify-content: center;
  min-height: 300px;
  position: relative; overflow: hidden;
}
.feature-visual::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(37,99,235,0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(37,99,235,0.07) 1px, transparent 1px);
  background-size: 32px 32px;
}
.feature-visual svg {
  position: relative; z-index: 1;
  width: 100%; max-width: 180px;
  color: var(--primary); opacity: 0.55;
}
.feature-eyebrow {
  font-size: 0.75rem; font-weight: 700;
  color: var(--primary-light);
  text-transform: uppercase; letter-spacing: 0.1em;
  margin-bottom: 14px;
}
.feature-content h2 { margin-bottom: 16px; }
.feature-content > p { font-size: 0.975rem; margin-bottom: 28px; }
.feature-list { display: flex; flex-direction: column; gap: 14px; margin-bottom: 32px; }
.feature-list-item { display: flex; align-items: flex-start; gap: 12px; }
.feature-list-item-icon {
  width: 26px; height: 26px;
  background: var(--blue-50);
  border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0; margin-top: 1px;
}
.feature-list-item-icon svg { width: 14px; height: 14px; color: var(--primary-light); }
.feature-list-item p { font-size: 0.9rem; margin: 0; }

/* === CTA SECTION === */
.cta-section {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  padding: clamp(64px, 8vw, 104px) 0;
  text-align: center;
  position: relative; overflow: hidden;
}
.cta-section::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.05) 1px, transparent 1px);
  background-size: 52px 52px;
}
.cta-inner { position: relative; z-index: 1; }
.cta-section h2 { color: var(--white); margin-bottom: 16px; }
.cta-section .lead {
  color: rgba(255,255,255,0.72);
  font-size: 1.075rem;
  margin-bottom: 36px;
  max-width: 560px;
  margin-left: auto; margin-right: auto;
}

/* === TRUST / COMPLIANCE BAR === */
.trust-bar {
  background: var(--bg-subtle);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 18px 0;
  overflow: hidden;
}
.trust-bar-inner {
  display: flex; align-items: center; justify-content: center; gap: 32px;
  overflow-x: auto; padding-bottom: 2px;
  scrollbar-width: none;
}
.trust-bar-inner::-webkit-scrollbar { display: none; }
.trust-item {
  display: flex; align-items: center; gap: 8px;
  white-space: nowrap; flex-shrink: 0;
}
.trust-item svg { width: 15px; height: 15px; color: var(--primary-light); }
.trust-item span { font-size: 0.78rem; font-weight: 600; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.07em; }

/* === ABOUT TEASER (home) === */
.about-teaser {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 72px;
  align-items: center;
}
.about-visual {
  background: linear-gradient(135deg, var(--blue-50) 0%, #D9EAFF 100%);
  border-radius: var(--radius-xl);
  padding: 0;
  min-height: 460px;
  display: flex; flex-direction: column;
  justify-content: flex-end;
  position: relative; overflow: hidden;
}
.about-visual::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(37,99,235,0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(37,99,235,0.06) 1px, transparent 1px);
  background-size: 36px 36px;
  z-index: 0;
}
/* Architect blueprint SVG */
.about-blueprint {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  z-index: 1;
}
.about-visual-stat {
  position: relative; z-index: 2;
  background: rgba(255,255,255,0.93);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.85);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin: 0 32px 32px;
  display: grid; grid-template-columns: 1fr 1fr 1fr;
  gap: 0; text-align: center;
  box-shadow: 0 4px 28px rgba(37,99,235,0.1);
}
.about-visual-stat > div {
  padding: 0 16px;
}
.about-visual-stat > div + div {
  border-left: 1px solid var(--border);
}
.about-stat-num { font-size: 1.75rem; font-weight: 800; color: var(--primary); line-height: 1; margin-bottom: 4px; }
.about-stat-lbl { font-size: 0.75rem; font-weight: 500; color: var(--text-muted); }
.about-content h2 { margin-bottom: 18px; }
.about-content > p { margin-bottom: 20px; font-size: 0.975rem; }
.about-content ul { margin-bottom: 32px; }
.about-content ul li {
  display: flex; align-items: flex-start; gap: 10px;
  padding: 9px 0; border-bottom: 1px solid var(--border-light);
  font-size: 0.9rem; color: var(--text-muted);
}
.about-content ul li:last-child { border-bottom: none; }
.about-content ul li svg { width: 16px; height: 16px; color: var(--primary-light); flex-shrink: 0; margin-top: 3px; }

/* === PROJECT CARDS === */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(330px, 1fr));
  gap: 28px;
}
.project-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: var(--transition);
}
.project-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}
.project-card-img {
  height: 200px;
  background: linear-gradient(135deg, var(--blue-50) 0%, #D0E4FF 100%);
  display: flex; align-items: center; justify-content: center;
  position: relative; overflow: hidden;
}
.project-card-img::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(37,99,235,0.09) 1px, transparent 1px),
    linear-gradient(90deg, rgba(37,99,235,0.09) 1px, transparent 1px);
  background-size: 28px 28px;
}
.project-card-img svg { position: relative; z-index: 1; width: 60px; height: 60px; color: var(--primary); opacity: 0.28; }
.project-card-tag {
  position: absolute; top: 12px; left: 12px;
  padding: 4px 11px;
  background: var(--white);
  border-radius: 20px;
  font-size: 0.73rem; font-weight: 700;
  color: var(--primary);
  box-shadow: var(--shadow-xs);
  z-index: 2;
}
.project-card-body { padding: 24px; }
.project-badges { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 12px; }
.badge {
  padding: 3px 10px;
  background: var(--blue-50);
  border-radius: 12px;
  font-size: 0.73rem; font-weight: 600;
  color: var(--primary-light);
}
.project-card h3 { font-size: 1rem; margin-bottom: 8px; }
.project-card p { font-size: 0.85rem; margin-bottom: 16px; }

/* Filter tabs */
.filter-tabs { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 40px; }
.filter-tab {
  padding: 9px 20px;
  border-radius: 20px;
  font-size: 0.85rem; font-weight: 600;
  cursor: pointer; transition: var(--transition);
  border: 1.5px solid var(--border);
  background: var(--white);
  color: var(--text-muted);
}
.filter-tab.active,
.filter-tab:hover {
  background: var(--primary);
  color: var(--white);
  border-color: var(--primary);
}

/* === CONTACT LAYOUT === */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 56px;
  align-items: start;
}
.contact-info-block { display: flex; flex-direction: column; gap: 0; }
.contact-info-title { font-size: 1.4rem; font-weight: 700; margin-bottom: 8px; }
.contact-info-desc { font-size: 0.9rem; margin-bottom: 32px; }
.contact-services-list {
  display: flex; flex-direction: column; gap: 8px;
  margin-bottom: 32px;
}
.contact-service-item {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 16px;
  background: var(--blue-50);
  border: 1px solid var(--blue-100);
  border-radius: var(--radius-sm);
  font-size: 0.875rem; font-weight: 500;
  color: var(--text);
}
.contact-service-item svg { width: 16px; height: 16px; color: var(--primary-light); flex-shrink: 0; }
.contact-details { display: flex; flex-direction: column; gap: 0; }
.contact-detail {
  display: flex; align-items: flex-start; gap: 14px;
  padding: 16px 0;
  border-bottom: 1px solid var(--border-light);
}
.contact-detail:last-child { border-bottom: none; }
.contact-detail-icon {
  width: 40px; height: 40px;
  background: var(--blue-50);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
}
.contact-detail-icon svg { width: 18px; height: 18px; color: var(--primary-light); }
.contact-detail-label {
  font-size: 0.72rem; font-weight: 700;
  color: var(--text-light);
  text-transform: uppercase; letter-spacing: 0.08em;
  margin-bottom: 3px;
}
.contact-detail-value { font-size: 0.925rem; font-weight: 500; color: var(--text); }
.contact-detail-value a { color: var(--primary-light); transition: color var(--transition); }
.contact-detail-value a:hover { color: var(--primary); text-decoration: underline; }

/* === FORM === */
.contact-form-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: var(--shadow-sm);
}
.form-title { font-size: 1.25rem; font-weight: 700; margin-bottom: 24px; }
.form-group { margin-bottom: 18px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-label {
  display: block;
  font-size: 0.85rem; font-weight: 600;
  color: var(--text);
  margin-bottom: 7px;
}
.form-label .req { color: #EF4444; margin-left: 2px; }
.form-input {
  width: 100%;
  padding: 11px 15px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.925rem;
  color: var(--text);
  background: var(--white);
  transition: var(--transition);
  font-family: inherit;
  -webkit-appearance: none;
}
.form-input:focus {
  outline: none;
  border-color: var(--primary-light);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.11);
}
.form-input::placeholder { color: var(--text-light); }
textarea.form-input { resize: vertical; min-height: 110px; line-height: 1.6; }
select.form-input {
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3E%3Cpath stroke='%2394A3B8' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='m6 8 4 4 4-4'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 20px;
  padding-right: 40px;
}
.form-checkboxes-title { font-size: 0.85rem; font-weight: 600; color: var(--text); margin-bottom: 10px; }
.form-checkboxes { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.form-checkbox-item {
  display: flex; align-items: center; gap: 8px;
  cursor: pointer;
  padding: 9px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  transition: var(--transition);
  font-size: 0.83rem; font-weight: 500;
  color: var(--text-muted);
  user-select: none;
}
.form-checkbox-item:hover {
  border-color: var(--primary-light);
  color: var(--primary);
  background: var(--blue-50);
}
.form-checkbox-item input { width: 15px; height: 15px; accent-color: var(--primary-light); flex-shrink: 0; }
.form-privacy {
  font-size: 0.78rem; color: var(--text-light);
  margin-bottom: 18px; line-height: 1.55;
}
.form-success {
  display: none;
  text-align: center;
  padding: 32px;
}
.form-success svg { width: 48px; height: 48px; color: var(--success); margin: 0 auto 16px; }
.form-success h3 { margin-bottom: 8px; }
.form-success p { font-size: 0.9rem; }

/* === FOOTER === */
.footer {
  background: var(--primary);
  color: rgba(255,255,255,0.78);
  padding: 60px 0 32px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}
.footer-logo {
  display: flex; align-items: baseline; gap: 3px;
  margin-bottom: 16px;
}
.footer-logo .logo-zk  { font-size: 1.5rem; font-weight: 900; color: var(--white); letter-spacing: -0.04em; }
.footer-logo .logo-eng { font-size: 0.9rem; font-weight: 400; color: rgba(255,255,255,0.55); margin-left: 3px; }
.footer-tagline {
  font-size: 0.875rem; color: rgba(255,255,255,0.58);
  line-height: 1.65; margin-bottom: 22px; max-width: 280px;
}
.footer-contact-item {
  display: flex; align-items: center; gap: 10px;
  font-size: 0.85rem; color: rgba(255,255,255,0.65);
  margin-bottom: 10px;
}
.footer-contact-item svg { width: 15px; height: 15px; opacity: 0.65; flex-shrink: 0; }
.footer-contact-item a { color: rgba(255,255,255,0.85); transition: color var(--transition); }
.footer-contact-item a:hover { color: var(--white); }
.footer-col-title {
  font-size: 0.7rem; font-weight: 700;
  color: rgba(255,255,255,0.45);
  text-transform: uppercase; letter-spacing: 0.12em;
  margin-bottom: 18px;
}
.footer-links { display: flex; flex-direction: column; gap: 11px; }
.footer-links a {
  font-size: 0.875rem; color: rgba(255,255,255,0.65);
  transition: color var(--transition);
}
.footer-links a:hover { color: var(--white); }
.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid rgba(255,255,255,0.1);
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 12px;
}
.footer-bottom p { font-size: 0.78rem; color: rgba(255,255,255,0.38); }

/* === SCROLL REVEAL === */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.65s cubic-bezier(0.16,1,0.3,1), transform 0.65s cubic-bezier(0.16,1,0.3,1);
}
.reveal.revealed { opacity: 1; transform: none; }
.reveal-delay-1 { transition-delay: 0.08s; }
.reveal-delay-2 { transition-delay: 0.16s; }
.reveal-delay-3 { transition-delay: 0.24s; }
.reveal-delay-4 { transition-delay: 0.32s; }

/* === MISCELLANEOUS === */
.divider { height: 1px; background: var(--border); margin: 0; }
.note-box {
  background: var(--blue-50);
  border: 1px solid var(--blue-100);
  border-left: 4px solid var(--primary-light);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  font-size: 0.875rem; color: var(--text-muted);
  line-height: 1.7;
}
.note-box strong { color: var(--primary); }

/* === RESPONSIVE === */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-visual { display: none; }
  .about-teaser { grid-template-columns: 1fr; gap: 40px; }
  .about-visual { min-height: 280px; padding: 36px 32px; }
  .feature-row { grid-template-columns: 1fr; gap: 40px; }
  .feature-row.reverse .feature-visual { order: unset; }
  .feature-row.reverse .feature-content { order: unset; }
  .feature-row { margin-bottom: 0 !important; }
  .contact-grid { grid-template-columns: 1fr; gap: 36px; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 36px; }
}
@media (max-width: 768px) {
  :root {
    --nav-height: 64px;
    --container-pad: 24px;
  }

  /* Nav */
  .nav-links, .nav-right { display: none; }
  .nav-hamburger { display: flex; padding: 12px 10px; }
  .nav-mobile-footer .btn-primary { width: 100%; justify-content: center; text-align: center; }

  /* Layout */
  .section-header { margin-bottom: 40px; }
  .page-header-inner { padding-top: 36px; padding-bottom: 52px; }

  /* Hero — centered layout on mobile */
  .hero-content { text-align: center; }
  .hero-badge { display: inline-flex; }
  .hero-lead { margin-left: auto; margin-right: auto; }
  .hero-ctas {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: 32px;
    gap: 12px;
  }
  .hero-ctas a, .hero-ctas button {
    width: calc(50% - 6px);
    justify-content: center;
    text-align: center;
    padding-top: 10px;
    padding-bottom: 10px;
    padding-left: 12px;
    padding-right: 12px;
  }
  .hero-trust { justify-content: center; }

  /* Grids → single column */
  .services-grid { grid-template-columns: 1fr; }
  .info-cards-grid { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .form-checkboxes { grid-template-columns: 1fr; }
  .technique-item { grid-template-columns: 1fr; gap: 20px; padding: 24px 20px; }
  .technique-content ul { grid-template-columns: 1fr; }

  /* Cards — reduced padding */
  .service-card { padding: 24px 20px; }
  .info-card { padding: 28px 20px; }
  .feature-visual { padding: 32px 24px; min-height: 220px; }
  .contact-form-card { padding: 28px 20px; }

  /* Footer */
  .footer { padding: 48px 0 24px; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .footer-links a { padding: 6px 0; display: block; }

  /* Touch targets */
  .filter-tab { padding: 11px 20px; }
  .about-visual { min-height: 280px; padding: 32px 24px; }
}
@media (max-width: 480px) {
  :root { --container-pad: 20px; }

  /* Buttons full-width in CTA sections */
  .cta-btns { flex-direction: column; align-items: stretch; }
  .cta-btns a, .cta-btns button { width: 100%; justify-content: center; }

  /* Form */
  .contact-form-card { padding: 20px 16px; }

  /* Page header */
  .page-header-inner { padding-top: 32px; padding-bottom: 48px; }

  /* Stats */
  .about-stat-num { font-size: 1.4rem; }
  .about-visual-stat { padding: 16px 12px; gap: 8px; }

  /* Hero trust bar */
  .hero-trust { gap: 14px; padding-top: 20px; }

  /* Hero h1 — scale down for small screens */
  .hero h1 { font-size: clamp(1.55rem, 8vw, 2rem); }
  h1 { overflow-wrap: break-word; }
}

/* === REDUCED MOTION === */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}