:root {
  --color-dark: #0A1628;
  --color-dark-mid: #0F2236;
  --color-accent: #2DD4BF;
  --color-accent-secondary: #3B82F6;
  --color-surface-light: #F8FAFC;
  --color-surface-white: #FFFFFF;
  --color-text-primary: #1E293B;
  --color-text-muted: #64748B;
  --color-border: #E2E8F0;
  --max-width: 1200px;
  --radius-card: 12px;
  --radius-btn: 8px;
  --radius-pill: 9999px;
  --section-padding: 100px;
  --card-padding: 32px;
  --font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-family);
  color: var(--color-text-primary);
  line-height: 1.7;
  font-size: 1rem;
  -webkit-font-smoothing: antialiased;
}

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* Navbar */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  transition: background-color 0.3s, border-color 0.3s;
  border-bottom: 1px solid transparent;
}
.navbar.scrolled {
  background-color: var(--color-dark);
  border-bottom-color: rgba(255,255,255,0.08);
}
.nav-container {
  max-width: var(--max-width); margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.nav-logo {
  color: #fff; font-weight: 700; font-size: 1.25rem; text-decoration: none;
}
.nav-links { display: flex; gap: 28px; list-style: none; }
.nav-links a {
  color: rgba(255,255,255,0.7); text-decoration: none; font-size: 0.8125rem;
  letter-spacing: 0.02em; text-transform: uppercase; transition: color 0.2s;
  white-space: nowrap;
}
.nav-links a:hover { color: #fff; }
.nav-hamburger {
  display: none; background: none; border: none; cursor: pointer;
  flex-direction: column; gap: 5px; padding: 4px;
}
.hamburger-line {
  display: block; width: 24px; height: 2px; background: #fff;
  transition: transform 0.3s, opacity 0.3s;
}

/* Hero */
.hero {
  min-height: 100vh; display: flex; flex-direction: column;
  align-items: center; justify-content: center; text-align: center;
  background: linear-gradient(135deg, var(--color-dark) 0%, var(--color-dark-mid) 50%, var(--color-dark) 100%);
  position: relative; overflow: hidden; padding: 0 24px;
}
.hero-bg {
  position: absolute; inset: 0; z-index: 0;
}
.hero-network { width: 100%; height: 100%; opacity: 0.06; }
.hero-content { position: relative; z-index: 1; max-width: 800px; }
.hero h1 {
  color: #fff; font-size: clamp(2.2rem, 5vw, 3.5rem); font-weight: 700;
  line-height: 1.2; margin-bottom: 0;
}
.hero p {
  color: rgba(255,255,255,0.65); font-size: clamp(1.1rem, 2.2vw, 1.35rem);
  max-width: 700px; margin: 24px auto 0;
}
.cta-button {
  display: inline-block; margin-top: 40px; padding: 14px 32px;
  background: var(--color-accent); color: var(--color-dark);
  font-weight: 600; font-size: 1rem; text-decoration: none;
  border-radius: var(--radius-btn); transition: transform 0.2s, box-shadow 0.2s;
}
.cta-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(45, 212, 191, 0.3);
}
.scroll-indicator {
  position: absolute; bottom: 40px; left: 50%; transform: translateX(-50%);
  animation: bounce 2s infinite; z-index: 1;
}
@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(10px); }
}

/* Section common */
section { padding: var(--section-padding) 0; }
.section-header { text-align: center; margin-bottom: 56px; }
.section-pill {
  display: inline-block; font-size: 0.75rem; font-weight: 600;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--color-accent);
  background: rgba(45,212,191,0.1); padding: 6px 16px; border-radius: var(--radius-pill);
  margin-bottom: 16px;
}
section h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.5rem); font-weight: 700;
  color: var(--color-text-primary); margin-bottom: 24px;
}
.section-intro {
  text-align: center; max-width: 800px; margin: 0 auto 56px;
  color: var(--color-text-muted); font-size: 1.1rem; line-height: 1.8;
}

/* Projects (main site) */
.projects { background: var(--color-surface-light); }
.project-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 24px;
  justify-items: center;
}
.project-card {
  background: var(--color-surface-white); border: 1px solid var(--color-border);
  border-radius: var(--radius-card); padding: 48px;
  transition: transform 0.2s, box-shadow 0.2s; max-width: 600px; width: 100%;
}
.project-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 32px rgba(0,0,0,0.12);
}
.card-icon { margin-bottom: 24px; }
.project-card h3 {
  font-size: 1.5rem; font-weight: 700; margin-bottom: 16px;
  color: var(--color-text-primary);
}
.project-card p { color: var(--color-text-muted); font-size: 1.05rem; line-height: 1.7; margin-bottom: 28px; }
.project-link {
  color: var(--color-accent); text-decoration: none; font-weight: 700; font-size: 1rem;
  transition: color 0.2s;
}
.project-link:hover { color: var(--color-dark); }

/* Problem / Rationale sections */
.problem, .rationale { background: var(--color-surface-white); }
.rationale-content { max-width: 860px; margin: 0 auto; }
.rationale-text p {
  color: var(--color-text-muted); font-size: 1.1rem; line-height: 1.8; margin-bottom: 20px;
}
.rationale-text p:last-child { margin-bottom: 0; }

/* Solution / Objective section */
.solution, .objective { background: var(--color-surface-light); }
.objective-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 64px;
  align-items: center; max-width: 1100px; margin: 0 auto;
}
.objective-text p {
  color: var(--color-text-muted); font-size: 1.05rem; line-height: 1.8; margin-bottom: 18px;
}
.objective-text p:last-child { margin-bottom: 0; }
.objective-visual svg {
  width: 100%; max-width: 360px; margin: 0 auto; display: block;
}

/* Technical / Features */
.technical { background: var(--color-surface-white); }
.feature-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 32px;
}
.feature-block {
  display: flex; gap: 20px; align-items: flex-start;
  padding: 28px; border-radius: var(--radius-card);
  border: 1px solid var(--color-border);
  transition: transform 0.2s, box-shadow 0.2s;
}
.feature-block:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.08);
}
.feature-icon { flex-shrink: 0; margin-top: 4px; }
.feature-text h3 {
  font-size: 1.1rem; font-weight: 700; margin-bottom: 8px;
  color: var(--color-text-primary);
}
.feature-text p {
  color: var(--color-text-muted); font-size: 0.95rem; line-height: 1.7;
}

/* Deployment / Infrastructure */
.deployment { background: var(--color-surface-light); }
.infra-cards {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 28px;
  max-width: 1100px; margin: 0 auto;
}
.infra-card {
  background: var(--color-surface-white); border: 1px solid var(--color-border);
  border-radius: var(--radius-card); padding: 40px 32px;
  transition: transform 0.2s, box-shadow 0.2s; position: relative; overflow: hidden;
}
.infra-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0,0,0,0.1);
}
.infra-card .card-icon { margin-bottom: 20px; }
.infra-card h3 {
  font-size: 1.2rem; font-weight: 700; margin-bottom: 14px; margin-top: 10px;
  color: var(--color-text-primary);
}
.infra-card p {
  color: var(--color-text-muted); font-size: 0.95rem; line-height: 1.7;
}

/* Card badges */
.card-badge {
  display: inline-block; font-size: 0.6875rem; font-weight: 700;
  letter-spacing: 0.08em; text-transform: uppercase;
  padding: 4px 12px; border-radius: var(--radius-pill);
}
.card-badge.phase1 { background: rgba(45,212,191,0.15); color: #0D9488; }
.card-badge.phase2 { background: rgba(59,130,246,0.12); color: #2563EB; }
.card-badge.phase3 { background: rgba(139,92,246,0.12); color: #7C3AED; }
.card-badge.active { background: rgba(45,212,191,0.15); color: #0D9488; }
.card-badge.pending-badge { background: rgba(251,191,36,0.15); color: #B45309; }
.card-badge.exploratory { background: rgba(139,92,246,0.12); color: #7C3AED; }

/* Roadmap / Timeline */
.roadmap { background: var(--color-surface-white); }
.timeline {
  max-width: 800px; margin: 0 auto; position: relative;
  padding-left: 40px;
}
.timeline::before {
  content: ''; position: absolute; left: 15px; top: 0; bottom: 0;
  width: 2px; background: var(--color-border);
}
.timeline-item {
  position: relative; margin-bottom: 48px;
}
.timeline-item:last-child { margin-bottom: 0; }
.timeline-dot {
  position: absolute; left: -33px; top: 28px;
  width: 12px; height: 12px; border-radius: 50%;
  border: 2px solid var(--color-accent); background: var(--color-surface-white);
}
.timeline-dot.active {
  background: var(--color-accent);
  box-shadow: 0 0 0 4px rgba(45,212,191,0.2);
}
.timeline-dot.pending {
  border-color: var(--color-border);
  background: var(--color-surface-light);
}
.timeline-card {
  border-radius: var(--radius-card); padding: 32px;
  border: 1px solid var(--color-border);
  background: var(--color-surface-white);
}
.timeline-card.phase1-border { border-left: 3px solid #0D9488; }
.timeline-card.phase2-border { border-left: 3px solid #2563EB; }
.timeline-card.phase3-border { border-left: 3px solid #7C3AED; }
.timeline-card h3 {
  font-size: 1.15rem; font-weight: 700; margin-bottom: 14px; margin-top: 10px;
  color: var(--color-text-primary);
}
.timeline-card p {
  color: var(--color-text-muted); font-size: 0.95rem; line-height: 1.7; margin-bottom: 10px;
}
.timeline-card p:last-child { margin-bottom: 0; }
.condition-note {
  font-style: italic; color: var(--color-text-muted) !important;
  font-size: 0.875rem !important; opacity: 0.8;
}

/* Team */
.team { background: var(--color-surface-light); }
.team-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 32px;
  max-width: 1000px; margin: 0 auto;
}
.team-card {
  text-align: center; padding: 40px 28px;
  background: var(--color-surface-white); border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  transition: transform 0.2s, box-shadow 0.2s;
}
.team-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0,0,0,0.1);
}
.team-card .avatar {
  width: 96px; height: 96px; border-radius: 50%; overflow: hidden;
  margin: 0 auto 20px; border: 3px solid var(--color-accent);
}
.team-card .avatar img {
  width: 100%; height: 100%; object-fit: cover;
}
.team-card h3 {
  font-size: 1.15rem; font-weight: 700; margin-bottom: 10px;
  color: var(--color-text-primary);
}
.team-card p {
  color: var(--color-text-muted); font-size: 0.9rem; line-height: 1.7;
}

/* Footer */
.footer { background: var(--color-dark); padding: 60px 24px; text-align: center; }
.footer-divider { width: 100%; height: 1px; background: rgba(255,255,255,0.08); margin-bottom: 32px; }
.footer-heading {
  color: rgba(255,255,255,0.4); font-size: 0.75rem; letter-spacing: 0.1em;
  text-transform: uppercase; margin-bottom: 24px;
}
.footer-line { color: rgba(255,255,255,0.6); font-size: 0.9rem; margin-bottom: 8px; }
.footer-line a { color: var(--color-accent); text-decoration: none; transition: opacity 0.2s; }
.footer-line a:hover { opacity: 0.8; }
.footer-copy { color: rgba(255,255,255,0.3); font-size: 0.8rem; margin-top: 24px; }

/* Scroll reveal */
.reveal {
  opacity: 0; transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* Dropdown */
.nav-dropdown { position: relative; display: inline-block; }
.dropdown-trigger {
  color: rgba(255,255,255,0.7); cursor: pointer; font-size: 0.8125rem;
  letter-spacing: 0.02em; text-transform: uppercase; transition: color 0.2s;
  display: flex; align-items: center; gap: 4px;
}
.dropdown-trigger:hover { color: #fff; }
.dropdown-trigger::after { content: '▾'; font-size: 0.7em; }

.dropdown-menu {
  display: none; position: absolute; top: 100%; left: 0;
  background: var(--color-dark); border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-btn); min-width: 150px; padding: 8px 0;
  box-shadow: 0 8px 24px rgba(0,0,0,0.2); z-index: 1001;
}
.dropdown-menu a {
  color: rgba(255,255,255,0.7); text-decoration: none; font-size: 0.875rem;
  padding: 8px 16px; display: block; transition: background 0.2s, color 0.2s;
}
.dropdown-menu a:hover { background: rgba(255,255,255,0.05); color: #fff; }

.nav-dropdown:hover .dropdown-menu { display: block; }

/* Responsive */
@media (max-width: 1024px) {
  .nav-links { gap: 18px; }
  .nav-links a { font-size: 0.75rem; }
}

@media (max-width: 768px) {
  :root { --section-padding: 72px; --card-padding: 24px; }
  .nav-hamburger { display: flex; }
  .nav-links {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    background: var(--color-dark); flex-direction: column; padding: 24px;
    gap: 16px; border-bottom: 1px solid rgba(255,255,255,0.08);
  }
  .nav-links.open { display: flex; }
  .nav-links a { font-size: 0.875rem; }
  .objective-grid { grid-template-columns: 1fr; gap: 40px; }
  .objective-visual { order: -1; }
  .objective-visual svg { max-width: 260px; }
  .feature-grid { grid-template-columns: 1fr; }
  .infra-cards { grid-template-columns: 1fr; }
  .team-grid { grid-template-columns: 1fr; max-width: 400px; }
  .timeline { padding-left: 36px; }
  .timeline-dot { left: -29px; }
  .project-card { padding: 32px; }
  .infra-card { padding: 32px 24px; }
  .dropdown-menu {
    position: static; display: block; background: transparent; border: none;
    box-shadow: none; padding: 0; margin-top: 8px;
  }
  .dropdown-menu a { padding-left: 20px; }
}