/* === Google Fonts === */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

/* === CSS Custom Properties === */
:root {
  --bg-start: #1a3a6b;
  --bg-end: #0a1628;
  --accent: #7eb8e0;
  --heading: #ffffff;
  --body: #a8c4d8;
  --section-bg: #0f2035;
  --section-alt: #0d1e38;
  --border: rgba(126, 184, 224, 0.15);
  --footer-bg: #060f1a;
  --nav-bg: rgba(10, 22, 40, 0.95);
  --font-body: 'Inter', system-ui, sans-serif;
  --max-width: 1200px;
  --nav-height: 72px;
}

/* === Reset === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-body);
  background-color: var(--bg-end);
  background: linear-gradient(160deg, var(--bg-start) 0%, var(--bg-end) 50%) fixed;
  color: var(--body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

/* === Container === */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
}

/* === Section spacing === */
.section { padding: 100px 0; }
.section-alt { background: var(--section-alt); }

/* === Typography === */
h1, h2, h3, h4 { color: var(--heading); line-height: 1.2; }
h1 { font-size: clamp(2.2rem, 5vw, 3.8rem); font-weight: 900; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.8rem, 3vw, 2.6rem); font-weight: 800; }
h3 { font-size: 1.25rem; font-weight: 700; }
h4 { font-size: 1rem; font-weight: 600; }
p { color: var(--body); line-height: 1.7; }

/* === Label (small caps above headings) === */
.label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 16px;
}

/* === Divider === */
.divider {
  width: 48px;
  height: 3px;
  background: var(--accent);
  margin: 20px 0 32px;
}

/* === Buttons === */
.btn {
  display: inline-block;
  padding: 14px 32px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  transition: all 0.2s;
  cursor: pointer;
}
.btn-primary {
  background: var(--accent);
  color: var(--bg-end);
}
.btn-primary:hover { background: #a8d4f0; }
.btn-outline {
  border: 1px solid rgba(255,255,255,0.3);
  color: var(--heading);
}
.btn-outline:hover { border-color: var(--accent); color: var(--accent); }
.btn-accent {
  border: 1px solid var(--accent);
  color: var(--accent);
}
.btn-accent:hover { background: var(--accent); color: var(--bg-end); }

/* === Navigation === */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: transparent;
  transition: background 0.3s, box-shadow 0.3s;
}
.nav.scrolled {
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 var(--border);
}
.nav-inner {
  display: flex;
  align-items: center;
  height: 100%;
  gap: 32px;
}
.nav-logo {
  display: flex;
  flex-direction: column;
  line-height: 1;
  flex-shrink: 0;
}
.logo-vzb {
  font-size: 1.4rem;
  font-weight: 900;
  letter-spacing: 0.2em;
  color: var(--accent);
}
.logo-sub {
  font-size: 0.55rem;
  font-weight: 600;
  letter-spacing: 0.25em;
  color: var(--heading);
  opacity: 0.7;
  margin-top: 2px;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}
.nav-link {
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--body);
  padding: 6px 12px;
  position: relative;
  transition: color 0.2s;
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 12px;
  right: 12px;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transition: transform 0.2s;
}
.nav-link:hover, .nav-link.active { color: var(--heading); }
.nav-link:hover::after, .nav-link.active::after { transform: scaleX(1); }

.nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-shrink: 0;
}
.lang-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
}
.lang-btn {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--body);
  padding: 2px 4px;
  transition: color 0.2s;
}
.lang-btn:hover, .lang-btn.active { color: var(--accent); }
.lang-sep { color: var(--body); opacity: 0.3; font-size: 0.8rem; }

/* === Hamburger (mobile only) === */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}
.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--heading);
  transition: transform 0.3s, opacity 0.3s;
}
.nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* === Footer === */
.footer {
  background: var(--footer-bg);
  border-top: 1px solid var(--border);
}
.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: 48px;
  padding: 64px 32px;
}
.footer-brand .nav-logo { margin-bottom: 20px; }
.footer-copy {
  font-size: 0.78rem;
  color: var(--body);
  opacity: 0.6;
  margin-top: 8px;
}
.footer-heading {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 20px;
}
.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-nav a {
  font-size: 0.85rem;
  color: var(--body);
  transition: color 0.2s;
}
.footer-nav a:hover { color: var(--heading); }
.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.footer-contact a, .footer-contact span {
  font-size: 0.85rem;
  color: var(--body);
  transition: color 0.2s;
}
.footer-contact a:hover { color: var(--accent); }
.footer-bottom {
  border-top: 1px solid var(--border);
  padding: 16px 32px;
  font-size: 0.75rem;
  color: var(--body);
  opacity: 0.4;
}

/* === Hero === */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--nav-height);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 40%, rgba(26, 58, 107, 0.6) 0%, transparent 70%);
  pointer-events: none;
}
.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  padding: 80px 32px;
}
.hero-content h1 { margin-bottom: 24px; }
.hero-sub {
  font-size: 1.1rem;
  max-width: 560px;
  margin: 0 auto 40px;
  line-height: 1.7;
}
.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}
.hero-scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
}
.hero-scroll-indicator span {
  display: block;
  width: 1px;
  height: 48px;
  background: linear-gradient(to bottom, var(--accent), transparent);
  margin: 0 auto;
  animation: scrollPulse 2s ease-in-out infinite;
}
@keyframes scrollPulse {
  0%, 100% { opacity: 0.4; transform: scaleY(1); }
  50% { opacity: 1; transform: scaleY(1.2); }
}

/* === Stats bar === */
.stats-bar {
  background: var(--section-alt);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 40px 0;
}
.stats-inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
}
.stat {
  flex: 1;
  text-align: center;
  padding: 0 32px;
}
.stat-num {
  display: block;
  font-size: 2.6rem;
  font-weight: 900;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 8px;
}
.stat-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--body);
}
.stat-divider {
  width: 1px;
  height: 60px;
  background: var(--border);
  flex-shrink: 0;
}

/* === Section header === */
.section-header {
  max-width: 640px;
  margin-bottom: 56px;
}
.section-sub {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--body);
}

/* === Service cards (home teaser + services page) === */
.service-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.service-card {
  background: var(--section-alt);
  border: 1px solid var(--border);
  padding: 36px 28px;
  transition: border-color 0.2s, transform 0.2s;
}
.service-card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
}
.service-icon {
  font-size: 1.6rem;
  color: var(--accent);
  margin-bottom: 20px;
}
.service-card h3 { margin-bottom: 12px; }
.service-card p { font-size: 0.9rem; }
.section-footer-link { margin-top: 48px; }

/* === CTA Banner === */
.cta-banner {
  background: var(--section-alt);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 80px 0;
  text-align: center;
}
.cta-banner h2 { margin-bottom: 16px; }
.cta-banner p { margin-bottom: 36px; font-size: 1rem; }

/* === Page hero (inner pages) === */
.page-hero {
  padding: calc(var(--nav-height) + 80px) 0 80px;
  border-bottom: 1px solid var(--border);
}
.page-hero h1 { margin-bottom: 20px; }
.page-hero-sub {
  font-size: 1.1rem;
  max-width: 560px;
  color: var(--body);
}

/* === Two column layout === */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}
.two-col h3 { margin-bottom: 0; }
.two-col p { font-size: 0.95rem; line-height: 1.8; }

/* === Narrow content === */
.narrow { max-width: 720px; }
.narrow p { font-size: 1rem; line-height: 1.8; }

/* === Values grid === */
.values-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.value-card {
  padding: 36px 24px;
  border: 1px solid var(--border);
  transition: border-color 0.2s;
}
.value-card:hover { border-color: var(--accent); }
.value-icon {
  font-size: 1.5rem;
  color: var(--accent);
  margin-bottom: 16px;
}
.value-card h3 { margin-bottom: 12px; }
.value-card p { font-size: 0.87rem; line-height: 1.6; }

/* === Services page — 6 cards in 2-col grid === */
.service-cards-6 {
  grid-template-columns: repeat(2, 1fr);
}

/* === Project cards === */
.project-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.project-card {
  background: var(--section-alt);
  border: 1px solid var(--border);
  padding: 36px 32px;
  transition: border-color 0.2s, transform 0.2s;
}
.project-card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
}
.project-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.project-country {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--heading);
}
.project-sector {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 3px 10px;
  border-radius: 2px;
}
.project-sector.transport { background: rgba(126,184,224,0.15); color: var(--accent); }
.project-sector.energy { background: rgba(255,200,80,0.15); color: #ffc850; }
.project-sector.urban { background: rgba(100,220,150,0.15); color: #64dc96; }
.project-year {
  font-size: 0.78rem;
  color: var(--body);
  margin-left: auto;
}
.project-card h3 { margin-bottom: 12px; }
.project-card p { font-size: 0.9rem; line-height: 1.7; }

/* === Team page === */
.team-member {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}
.member-avatar {
  width: 200px;
  height: 240px;
  border-radius: 4px;
  object-fit: cover;
  object-position: center top;
  border: 1px solid var(--border);
  margin: 0 auto 32px;
  display: block;
}
.member-name {
  margin-bottom: 8px;
}
.member-title {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 28px;
}
.member-bio {
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--body);
  margin-bottom: 48px;
}
.team-rule {
  width: 48px;
  height: 1px;
  background: var(--border);
  margin: 0 auto 28px;
}
.team-network {
  font-size: 0.9rem;
  font-style: italic;
  color: var(--body);
  opacity: 0.65;
  max-width: 480px;
  margin: 0 auto;
}
.career-history {
  margin: 48px 0;
  text-align: left;
}
.career-heading {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 28px;
}
.career-item {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 0 24px;
  padding: 20px 0;
  border-top: 1px solid var(--border);
}
.career-item:last-child {
  border-bottom: 1px solid var(--border);
}
.career-period {
  font-size: 0.78rem;
  color: var(--body);
  opacity: 0.6;
  padding-top: 3px;
  white-space: nowrap;
}
.career-role {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--heading);
  margin-bottom: 4px;
}
.career-company {
  font-size: 0.85rem;
  color: var(--accent);
  margin-bottom: 3px;
}
.career-location {
  font-size: 0.8rem;
  color: var(--body);
  opacity: 0.6;
}

/* === Contact page === */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: start;
}
.contact-info h3 { margin-bottom: 0; }
.contact-items {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-bottom: 40px;
}
.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}
.contact-item-icon {
  color: var(--accent);
  font-size: 1rem;
  margin-top: 2px;
  flex-shrink: 0;
  width: 16px;
  text-align: center;
}
.contact-item-text {
  display: flex;
  flex-direction: column;
}
.contact-item-label {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 2px;
}
.contact-item-value {
  font-size: 0.9rem;
  color: var(--body);
  transition: color 0.2s;
}
a.contact-item-value:hover { color: var(--heading); }
.map-embed {
  border: 1px solid var(--border);
  overflow: hidden;
  margin-top: 8px;
}
.contact-form-col h3 { margin-bottom: 0; }
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 0;
}
.contact-form input,
.contact-form textarea {
  background: var(--section-alt);
  border: 1px solid var(--border);
  color: var(--heading);
  font-family: var(--font-body);
  font-size: 0.9rem;
  padding: 14px 16px;
  width: 100%;
  outline: none;
  transition: border-color 0.2s;
  resize: vertical;
}
.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: var(--body);
  opacity: 0.55;
}
.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--accent);
}
.form-success {
  color: var(--accent);
  font-size: 0.88rem;
  padding: 12px 0 0;
}
.contact-form button[disabled] { opacity: 0.6; cursor: not-allowed; }

/* === Responsive === */

/* Tablet: 960px */
@media (max-width: 960px) {
  .service-cards { grid-template-columns: repeat(2, 1fr); }
  .values-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}

/* Mobile: 768px — show hamburger, collapse nav links */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 16px 0 24px;
    border-bottom: 1px solid var(--border);
    gap: 0;
  }
  .nav-links.open { display: flex; }
  .nav-link {
    padding: 12px 24px;
    font-size: 0.9rem;
  }
  .nav-link::after { display: none; }
  .nav-hamburger { display: flex; }

  .two-col { grid-template-columns: 1fr; gap: 40px; }
  .contact-grid { grid-template-columns: 1fr; gap: 48px; }
  .project-cards { grid-template-columns: 1fr; }
  .service-cards-6 { grid-template-columns: 1fr; }

  .hero-content { padding: 60px 24px; }
  .section { padding: 64px 0; }
  .page-hero { padding: calc(var(--nav-height) + 48px) 0 48px; }
}

/* Small mobile: 640px */
@media (max-width: 640px) {
  .container { padding: 0 20px; }
  .service-cards { grid-template-columns: 1fr; }
  .values-grid { grid-template-columns: 1fr 1fr; }
  .stats-inner { flex-direction: column; gap: 32px; }
  .stat-divider { display: none; }
  .footer-inner { grid-template-columns: 1fr; gap: 32px; }
  h1 { font-size: clamp(1.8rem, 8vw, 3rem); }
  h2 { font-size: clamp(1.5rem, 6vw, 2.2rem); }
  .career-item { grid-template-columns: 1fr; gap: 4px; }
  .career-period { margin-bottom: 8px; }
}