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

:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #0f111a;
  --bg-card: rgba(20, 22, 35, 0.7);
  --bg-glass: rgba(255, 255, 255, 0.03);
  --text-primary: #f0f0f5;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  --accent-cyan: #00d4ff;
  --accent-purple: #8b5cf6;
  --accent-gradient: linear-gradient(135deg, #00d4ff 0%, #8b5cf6 100%);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 255, 255, 0.15);
  --shadow-glow: 0 0 30px rgba(0, 212, 255, 0.15);
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  display: block;
}

/* ========== BACKGROUND EFFECTS ========== */
.bg-mesh {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

.bg-mesh::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background:
    radial-gradient(circle at 20% 30%, rgba(0, 212, 255, 0.04) 0%, transparent 40%),
    radial-gradient(circle at 80% 70%, rgba(139, 92, 246, 0.04) 0%, transparent 40%),
    radial-gradient(circle at 50% 50%, rgba(0, 212, 255, 0.02) 0%, transparent 50%);
  animation: meshMove 20s ease-in-out infinite alternate;
}

@keyframes meshMove {
  0% { transform: translate(0, 0) rotate(0deg); }
  100% { transform: translate(-2%, -2%) rotate(2deg); }
}

.grid-overlay {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255,255,255,0.015) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.015) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(circle at center, black 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(circle at center, black 30%, transparent 80%);
}

/* ========== PARTICLES CANVAS ========== */
#particles-canvas {
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
}

/* ========== NAVIGATION ========== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 1rem 2rem;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  background: rgba(10, 10, 15, 0.7);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

.navbar.scrolled {
  padding: 0.6rem 2rem;
  background: rgba(10, 10, 15, 0.9);
}

.nav-container {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 1.3rem;
  font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

.logo span {
  -webkit-text-fill-color: var(--text-primary);
  font-weight: 500;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2.5rem;
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-gradient);
  transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text-primary);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.lang-toggle {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0.8rem;
  border-radius: 20px;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
}

.lang-toggle:hover {
  border-color: var(--border-hover);
  color: var(--text-primary);
}

.lang-toggle .lang-btn {
  padding: 0.2rem 0.5rem;
  border-radius: 12px;
  transition: var(--transition);
}

.lang-toggle .lang-btn.active {
  background: var(--accent-gradient);
  color: white;
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 5px;
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: var(--transition);
}

/* ========== MAIN CONTENT ========== */
main {
  position: relative;
  z-index: 2;
}

.section {
  padding: 6rem 2rem;
  max-width: 1400px;
  margin: 0 auto;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin-bottom: 3rem;
}

/* ========== HERO ========== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 8rem 2rem 4rem;
  position: relative;
}

.hero-content {
  max-width: 900px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border-radius: 50px;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--accent-cyan);
  margin-bottom: 2rem;
}

.hero-badge .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-cyan);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.2); }
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1.5rem;
  letter-spacing: -0.03em;
}

.hero h1 .gradient-text {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.2rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 2.5rem;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.9rem 2rem;
  border-radius: 12px;
  font-size: 0.95rem;
  font-weight: 600;
  transition: var(--transition);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--accent-gradient);
  color: white;
  box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 40px rgba(0, 212, 255, 0.3);
}

.btn-secondary {
  background: var(--bg-glass);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  border-color: var(--border-hover);
  background: rgba(255,255,255,0.05);
}

/* ========== CARDS ========== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 2rem;
  transition: var(--transition);
  backdrop-filter: blur(10px);
}

.card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: 0 20px 40px rgba(0,0,0,0.3);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  font-size: 1.5rem;
}

.card h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ========== STATS ========== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  margin-top: 4rem;
}

.stat-item {
  text-align: center;
  padding: 2rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  transition: var(--transition);
}

.stat-item:hover {
  border-color: var(--accent-cyan);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 0.5rem;
}

/* ========== TEAM ========== */
.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

.team-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
}

.team-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
}

.team-avatar {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: var(--accent-gradient);
  margin: 0 auto 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  font-weight: 700;
  color: white;
}

.team-card h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.3rem;
}

.team-card .role {
  color: var(--accent-cyan);
  font-size: 0.85rem;
  font-weight: 500;
}

/* ========== CONTACT ========== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

.contact-info-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.contact-info-item .icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.contact-info-item h4 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.contact-info-item p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.contact-form {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 2rem;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.8rem 1rem;
  border-radius: 10px;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.95rem;
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent-cyan);
  box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.1);
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

/* ========== LEGAL PAGES ========== */
.legal-content {
  max-width: 900px;
  margin: 0 auto;
  padding: 8rem 2rem 4rem;
}

.legal-header {
  text-align: center;
  margin-bottom: 3rem;
}

.legal-header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.legal-header .last-updated {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.legal-body {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 2.5rem;
}

.legal-body h2 {
  font-size: 1.3rem;
  font-weight: 600;
  margin: 2rem 0 1rem;
  color: var(--accent-cyan);
}

.legal-body h2:first-child {
  margin-top: 0;
}

.legal-body p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.8;
}

.legal-body ul {
  margin-left: 1.5rem;
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

.legal-body ul li {
  margin-bottom: 0.5rem;
  line-height: 1.7;
}

/* ========== FOOTER ========== */
.footer {
  border-top: 1px solid var(--border-color);
  padding: 3rem 2rem 2rem;
  background: rgba(10, 10, 15, 0.5);
  backdrop-filter: blur(10px);
  position: relative;
  z-index: 2;
}

.footer-grid {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 2rem;
}

.footer-brand .logo {
  margin-bottom: 1rem;
  display: inline-block;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.7;
}

.footer-col h4 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  color: var(--text-primary);
}

.footer-col a {
  display: block;
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 0.75rem;
  transition: var(--transition);
}

.footer-col a:hover {
  color: var(--accent-cyan);
}

.footer-bottom {
  max-width: 1400px;
  margin: 0 auto;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ========== BILINGUAL TOGGLE ========== */
.lang-en .zh-only, .lang-zh .en-only { display: none; }

/* ========== SCROLL ANIMATIONS ========== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ========== RESPONSIVE ========== */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(10, 10, 15, 0.98);
    flex-direction: column;
    padding: 1.5rem;
    gap: 1rem;
    border-bottom: 1px solid var(--border-color);
  }
  .nav-links.open {
    display: flex;
  }
  .mobile-menu-btn {
    display: flex;
  }
  .section {
    padding: 4rem 1.5rem;
  }
  .hero {
    padding: 7rem 1.5rem 3rem;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
  .legal-body {
    padding: 1.5rem;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 2rem;
  }
  .section-title {
    font-size: 1.8rem;
  }
  .card-grid {
    grid-template-columns: 1fr;
  }
}