/* ===========================
   CSS Variables & Reset
   =========================== */
:root {
  --color-bg: #0b0f1a;
  --color-surface: #121826;
  --color-surface-2: #1a2236;
  --color-border: #1e2d45;
  --color-accent: #4f8ef7;
  --color-accent-dark: #2563eb;
  --color-accent-glow: rgba(79, 142, 247, 0.15);
  --color-text: #e8edf5;
  --color-text-muted: #7a8caa;
  --color-white: #ffffff;
  --font: 'Inter', system-ui, sans-serif;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 40px rgba(79, 142, 247, 0.2);
  --transition: 0.3s ease;
  --nav-height: 72px;
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { display: block; max-width: 100%; }

.container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===========================
   Buttons
   =========================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  border: none;
  white-space: nowrap;
}
.btn-primary {
  background: var(--color-accent);
  color: var(--color-white);
}
.btn-primary:hover {
  background: var(--color-accent-dark);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}
.btn-secondary {
  background: transparent;
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
}
.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-2px);
}
.btn-outline {
  background: transparent;
  color: var(--color-accent);
  border: 1.5px solid var(--color-accent);
  padding: 10px 24px;
}
.btn-outline:hover {
  background: var(--color-accent-glow);
  transform: translateY(-2px);
}
.btn-full { width: 100%; }

/* ===========================
   Navigation
   =========================== */
#navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-height);
  z-index: 1000;
  background: rgba(11, 15, 26, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), background var(--transition);
}
#navbar.scrolled {
  border-color: var(--color-border);
  background: rgba(11, 15, 26, 0.97);
}
.nav-container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
}
.logo-accent {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: -0.5px;
}
.logo-text {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  display: none;
}
@media (min-width: 600px) { .logo-text { display: block; } }

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}
.nav-links li a {
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: all var(--transition);
}
.nav-links li a:hover { color: var(--color-text); background: var(--color-surface-2); }
.btn-nav {
  background: var(--color-accent) !important;
  color: var(--color-white) !important;
  padding: 8px 18px !important;
}
.btn-nav:hover { background: var(--color-accent-dark) !important; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-toggle span {
  display: block;
  width: 24px; height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition);
}

@media (max-width: 768px) {
  .nav-toggle { display: flex; }
  .nav-links {
    position: fixed;
    top: var(--nav-height); left: 0; right: 0;
    background: var(--color-surface);
    flex-direction: column;
    padding: 20px 24px;
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-110%);
    transition: transform var(--transition);
    gap: 4px;
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links li { width: 100%; }
  .nav-links li a { display: block; }
}

/* ===========================
   Hero
   =========================== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-height) + 60px) 24px 80px;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(79, 142, 247, 0.12) 0%, transparent 70%),
    radial-gradient(ellipse 60% 40% at 80% 80%, rgba(124, 99, 247, 0.08) 0%, transparent 60%);
  pointer-events: none;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(79,142,247,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(79,142,247,0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
}
.hero-content {
  position: relative;
  max-width: 800px;
}
.hero-eyebrow {
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 16px;
}
.hero-title {
  font-size: clamp(2.8rem, 7vw, 5.5rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
  color: var(--color-white);
}
.hero-title span { color: var(--color-accent); }
.hero-subtitle {
  font-size: clamp(1rem, 2.5vw, 1.2rem);
  color: var(--color-text-muted);
  max-width: 520px;
  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: 36px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
}
.scroll-dot {
  width: 6px; height: 6px;
  background: var(--color-accent);
  border-radius: 50%;
  animation: scrollBounce 1.8s ease-in-out infinite;
}
@keyframes scrollBounce {
  0%, 100% { transform: translateY(0); opacity: 1; }
  50% { transform: translateY(12px); opacity: 0.4; }
}

/* ===========================
   Stats Bar
   =========================== */
.stats-bar {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  padding: 40px 24px;
}
.stats-container {
  max-width: 1160px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  text-align: center;
}
@media (min-width: 640px) { .stats-container { grid-template-columns: repeat(4, 1fr); } }
.stat-number {
  display: block;
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: -0.03em;
}
.stat-label {
  display: block;
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-top: 4px;
  font-weight: 500;
}

/* ===========================
   Section Helpers
   =========================== */
.section-label {
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 16px;
}
.section-title {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--color-white);
  margin-bottom: 16px;
}
.section-subtitle {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  max-width: 560px;
  margin-bottom: 56px;
  line-height: 1.7;
}

/* ===========================
   About
   =========================== */
.about {
  padding: 100px 0;
}
.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  align-items: start;
}
@media (min-width: 900px) { .about-grid { grid-template-columns: 1fr 1fr; } }
.about-text h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--color-white);
  margin-bottom: 20px;
  line-height: 1.2;
}
.about-text p {
  color: var(--color-text-muted);
  line-height: 1.75;
  margin-bottom: 16px;
}
.about-text .btn { margin-top: 8px; }
.about-cards {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.about-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.about-card:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-glow);
}
.card-icon {
  font-size: 1.5rem;
  color: var(--color-accent);
  margin-bottom: 12px;
}
.about-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 8px;
}
.about-card p { color: var(--color-text-muted); font-size: 0.95rem; line-height: 1.7; }

/* ===========================
   Research
   =========================== */
.research {
  padding: 100px 0;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.research-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}
.research-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}
.research-icon {
  font-size: 2rem;
  margin-bottom: 16px;
  display: block;
}
.research-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 10px;
}
.research-card p { color: var(--color-text-muted); font-size: 0.92rem; line-height: 1.7; }

/* ===========================
   Team
   =========================== */
.team {
  padding: 100px 0;
}
.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 24px;
}
.team-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  text-align: center;
  transition: border-color var(--transition), transform var(--transition);
}
.team-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
}
.team-avatar {
  width: 64px; height: 64px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-white);
  margin: 0 auto 16px;
  letter-spacing: 0.5px;
}
.team-card h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 4px;
}
.team-role {
  font-size: 0.82rem;
  color: var(--color-accent);
  font-weight: 500;
  margin-bottom: 12px !important;
}
.team-bio {
  font-size: 0.88rem;
  color: var(--color-text-muted);
  line-height: 1.65;
}

/* ===========================
   Contact
   =========================== */
.contact {
  padding: 100px 0;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
}
.contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 60px;
  align-items: start;
}
@media (min-width: 900px) { .contact-grid { grid-template-columns: 1fr 1.2fr; } }
.contact-info h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--color-white);
  margin-bottom: 16px;
}
.contact-info > p {
  color: var(--color-text-muted);
  line-height: 1.75;
  margin-bottom: 32px;
}
.contact-details { display: flex; flex-direction: column; gap: 16px; }
.contact-details li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  color: var(--color-text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}
.detail-icon { font-size: 1.1rem; flex-shrink: 0; margin-top: 2px; }

.contact-form {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 40px 36px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
}
.form-group input,
.form-group textarea {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 12px 16px;
  color: var(--color-text);
  font-family: var(--font);
  font-size: 0.95rem;
  transition: border-color var(--transition), box-shadow var(--transition);
  resize: vertical;
}
.form-group input::placeholder,
.form-group textarea::placeholder { color: #3a4d67; }
.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-glow);
}
.form-success {
  text-align: center;
  color: #4ade80;
  font-size: 0.9rem;
  font-weight: 500;
  display: none;
}
.form-success.visible { display: block; }

/* ===========================
   Footer
   =========================== */
.footer {
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  padding: 64px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  margin-bottom: 48px;
}
@media (min-width: 640px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; } }
.footer-logo {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.footer-brand p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  line-height: 1.65;
  max-width: 260px;
}
.footer-links h4 {
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text);
  margin-bottom: 16px;
}
.footer-links ul { display: flex; flex-direction: column; gap: 10px; }
.footer-links ul li a {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  transition: color var(--transition);
}
.footer-links ul li a:hover { color: var(--color-accent); }
.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding: 20px 0;
  text-align: center;
}
.footer-bottom p { color: var(--color-text-muted); font-size: 0.85rem; }