/* ================= CSS VARIABLES & RESET ================= */
:root {
  --bg-dark: #0a0d14;
  --bg-darker: #06080d;
  --bg-card: #121722;
  --bg-card-hover: #182030;
  --text-main: #f3f6fa;
  --text-muted: #9ba5b7;
  --accent-primary: #00d2ff;
  --accent-secondary: #7a5af8;
  --border-color: rgba(255, 255, 255, 0.1);
  --container-width: 1240px;
  --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

ul {
  list-style: none;
}

.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section-padding {
  padding: 5.5rem 0;
}

.bg-darker {
  background-color: var(--bg-darker);
}

/* ================= TYPOGRAPHY & BUTTONS ================= */
.eyebrow, .section-tag {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent-primary);
  margin-bottom: 0.75rem;
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4.25rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
}

h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.015em;
}

.text-gradient {
  background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-size: 0.92rem;
  font-weight: 600;
  border-radius: 4px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: var(--transition);
}

.btn-primary {
  background: var(--text-main);
  color: var(--bg-dark);
}

.btn-primary:hover {
  background: var(--accent-primary);
  color: var(--bg-darker);
}

.btn-accent {
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  color: #fff;
  font-weight: 700;
}

.btn-outline {
  border-color: var(--border-color);
  color: var(--text-main);
}

.btn-outline:hover {
  border-color: var(--accent-primary);
  color: var(--accent-primary);
}

/* ================= HEADER & MEGA MENU ================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(10, 13, 20, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.brand-logo {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: 0.04em;
}

.logo-mark {
  color: var(--accent-primary);
}

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

.nav-link {
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  padding: 0.5rem 0;
}

.nav-link:hover, .nav-link.active {
  color: var(--accent-primary);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Mega Menu */
.mega-menu {
  display: none;
  position: absolute;
  top: 80px;
  left: 0;
  width: 100%;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  padding: 2.5rem 0;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.6);
}

.mega-menu.open {
  display: block;
}

.mega-menu-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1.2fr;
  gap: 2.5rem;
}

.mega-col h4 {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.mega-col ul li {
  margin-bottom: 0.65rem;
}

.mega-col ul a:hover {
  color: var(--accent-primary);
  padding-left: 4px;
}

.featured-box {
  background: rgba(255, 255, 255, 0.03);
  padding: 1.5rem;
  border-radius: 6px;
  border: 1px solid var(--border-color);
}

.badge {
  display: inline-block;
  font-size: 0.7rem;
  text-transform: uppercase;
  background: rgba(0, 210, 255, 0.15);
  color: var(--accent-primary);
  padding: 0.25rem 0.6rem;
  border-radius: 3px;
  margin-bottom: 0.75rem;
}

.text-link {
  display: inline-block;
  margin-top: 1rem;
  color: var(--accent-primary);
  font-weight: 600;
}

/* ================= HERO SECTION ================= */
.hero-section, .page-hero {
  padding: 6.5rem 0 5rem;
  background: radial-gradient(circle at 80% 20%, rgba(122, 90, 248, 0.18), transparent 45%),
              radial-gradient(circle at 20% 80%, rgba(0, 210, 255, 0.12), transparent 50%);
  border-bottom: 1px solid var(--border-color);
}

.hero-lead {
  font-size: 1.2rem;
  color: var(--text-muted);
  max-width: 680px;
  margin-bottom: 2.5rem;
}

.hero-search-wrapper {
  display: flex;
  max-width: 640px;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.hero-search-wrapper input {
  flex: 1;
  padding: 1rem 1.25rem;
  border-radius: 4px;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-main);
  font-size: 1rem;
}

.hero-search-wrapper input:focus {
  outline: none;
  border-color: var(--accent-primary);
}

.search-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.tag-btn {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.3rem 0.75rem;
  border-radius: 20px;
  cursor: pointer;
  font-size: 0.8rem;
  transition: var(--transition);
}

.tag-btn:hover {
  border-color: var(--accent-primary);
  color: var(--accent-primary);
}

/* ================= SOLUTIONS & PROJECTS GRIDS ================= */
.section-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 3rem;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.cards-grid, .projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.75rem;
}

.solution-card, .project-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 2.25rem;
  border-radius: 6px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

.solution-card:hover, .project-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(0, 210, 255, 0.4);
  transform: translateY(-4px);
}

.card-num {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent-primary);
  margin-bottom: 1rem;
}

.solution-card h3, .project-card h3 {
  font-size: 1.35rem;
  margin-bottom: 0.85rem;
  line-height: 1.3;
}

.solution-card p, .project-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
}

.card-link {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--accent-primary);
}

/* Filter Tabs */
.filter-tabs {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.tab-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 0.5rem 1rem;
  border-radius: 4px;
  cursor: pointer;
  font-weight: 600;
  transition: var(--transition);
}

.tab-btn.active, .tab-btn:hover {
  background: var(--accent-primary);
  color: var(--bg-darker);
  border-color: var(--accent-primary);
}

.region-pill {
  display: inline-block;
  align-self: flex-start;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--accent-secondary);
  margin-bottom: 0.75rem;
}

.project-meta {
  font-size: 0.82rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
  margin-top: 1.5rem;
}

/* ================= SUSTAINABILITY & FOOTER ================= */
.sustainability-box {
  background: linear-gradient(135deg, rgba(18, 23, 34, 0.95), rgba(122, 90, 248, 0.15));
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 3.5rem;
}

.sust-content p {
  color: var(--text-muted);
  max-width: 760px;
  margin: 1.25rem 0 2rem;
}

.sust-pillars {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
}

.pillar {
  background: rgba(0, 0, 0, 0.25);
  padding: 1.25rem;
  border-left: 3px solid var(--accent-primary);
}

.pillar strong {
  display: block;
  margin-bottom: 0.35rem;
}

.pillar span {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.site-footer {
  background: var(--bg-darker);
  border-top: 1px solid var(--border-color);
  padding: 4rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.2fr;
  gap: 2.5rem;
  margin-bottom: 3rem;
}

.footer-brand p, .footer-contact p {
  color: var(--text-muted);
  margin-top: 0.75rem;
  font-size: 0.92rem;
}

.footer-links h4, .footer-contact h4 {
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
}

.footer-links ul li {
  margin-bottom: 0.5rem;
  color: var(--text-muted);
  font-size: 0.92rem;
}

.footer-links ul a:hover {
  color: var(--accent-primary);
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 1.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Responsive */
@media (max-width: 900px) {
  .mega-menu-grid, .footer-grid {
    grid-template-columns: 1fr;
  }
  .main-nav {
    display: none;
  }
  .mobile-menu-btn {
    display: block;
  }
}