/* ========================================
   U币交易所平台 - 全球合规持牌加密资产合约交易平台
   配色: 深色背景(#0d1b2a) + 契约绿(#00c087) + 金色点缀(#e8b830) + 白色
   ======================================== */

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

:root {
  --bg-primary: #0d1b2a;
  --bg-secondary: #111f35;
  --bg-card: #152238;
  --bg-card-hover: #1a2d48;
  --accent-green: #00c087;
  --accent-green-dark: #00a673;
  --accent-green-light: #00e5a0;
  --accent-gold: #e8b830;
  --accent-gold-light: #f0cc5a;
  --text-primary: #ffffff;
  --text-secondary: #b0c4d8;
  --text-muted: #7a8fa6;
  --border-color: #1e3350;
  --border-light: #2a4060;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.5);
  --shadow-glow-green: 0 0 20px rgba(0,192,135,0.15);
  --shadow-glow-gold: 0 0 20px rgba(232,184,48,0.15);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  --max-width: 1200px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; transition: color var(--transition-fast); }
ul, ol { list-style: none; }
img { max-width: 100%; height: auto; display: block; }

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

/* === Section Common === */
section { padding: 80px 0; }
.section-header { text-align: center; margin-bottom: 56px; }
.section-header h2 {
  font-size: 2.2rem; font-weight: 700; color: var(--text-primary);
  margin-bottom: 12px; position: relative; display: inline-block;
}
.section-header h2::after {
  content: ''; display: block; width: 60px; height: 3px;
  background: linear-gradient(90deg, var(--accent-green), var(--accent-gold));
  margin: 12px auto 0; border-radius: 2px;
}
.section-header p { font-size: 1.05rem; color: var(--text-secondary); max-width: 600px; margin: 0 auto; }

/* === Header & Navigation === */
.header { position: sticky; top: 0; z-index: 100; background: rgba(13,27,42,0.95); backdrop-filter: blur(20px); border-bottom: 1px solid var(--border-color); }

.navbar { display: flex; align-items: center; justify-content: space-between; padding: 16px 0; }
.navbar .brand { font-size: 1.5rem; font-weight: 700; color: var(--text-primary); display: flex; align-items: center; gap: 10px; }
.navbar .brand .brand-icon { width: 38px; height: 38px; border-radius: var(--radius-sm); background: linear-gradient(135deg, var(--accent-green), var(--accent-gold)); display: flex; align-items: center; justify-content: center; font-size: 1.2rem; font-weight: 900; color: #0d1b2a; }
.nav-links { display: flex; align-items: center; gap: 32px; }
.nav-links a { color: var(--text-secondary); font-size: 0.95rem; font-weight: 500; position: relative; padding: 6px 0; }
.nav-links a::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background: var(--accent-green); transition: width var(--transition-normal); }
.nav-links a:hover, .nav-links a.active { color: var(--accent-green); }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }
.nav-cta { background: var(--accent-green); color: #0d1b2a !important; padding: 8px 20px !important; border-radius: 50px; font-weight: 600 !important; transition: all var(--transition-fast) !important; }
.nav-cta:hover { background: var(--accent-green-light); box-shadow: 0 0 20px rgba(0,192,135,0.3); transform: translateY(-1px); }
.nav-cta::after { display: none !important; }
.menu-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; flex-direction: column; gap: 5px; }
.menu-toggle span { display: block; width: 26px; height: 2px; background: var(--text-primary); border-radius: 2px; transition: all var(--transition-fast); }
.menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }

/* === Buttons === */
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 28px; border-radius: 50px; font-size: 0.95rem; font-weight: 600; cursor: pointer; border: none; transition: all var(--transition-fast); text-align: center; }
.btn-primary { background: var(--accent-green); color: #0d1b2a; }
.btn-primary:hover { background: var(--accent-green-light); box-shadow: 0 0 24px rgba(0,192,135,0.35); transform: translateY(-2px); }
.btn-gold { background: var(--accent-gold); color: #0d1b2a; }
.btn-gold:hover { background: var(--accent-gold-light); box-shadow: 0 0 24px rgba(232,184,48,0.35); transform: translateY(-2px); }
.btn-outline { background: transparent; border: 2px solid var(--accent-green); color: var(--accent-green); }
.btn-outline:hover { background: var(--accent-green); color: #0d1b2a; }
.btn-lg { padding: 14px 36px; font-size: 1.05rem; }
.btn-sm { padding: 8px 18px; font-size: 0.85rem; }

/* === Hero Section === */
.hero { position: relative; min-height: 85vh; display: flex; align-items: center; padding: 100px 0; overflow: hidden; }
.hero::before { content: ''; position: absolute; top: -50%; right: -20%; width: 600px; height: 600px; background: radial-gradient(circle, rgba(0,192,135,0.08), transparent 70%); border-radius: 50%; pointer-events: none; }
.hero::after { content: ''; position: absolute; bottom: -30%; left: -10%; width: 500px; height: 500px; background: radial-gradient(circle, rgba(232,184,48,0.06), transparent 70%); border-radius: 50%; pointer-events: none; }
.hero .container { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; position: relative; z-index: 1; }
.hero-content { animation: fadeInUp 0.8s ease; }
.hero-badge { display: inline-block; background: rgba(0,192,135,0.1); color: var(--accent-green); padding: 6px 16px; border-radius: 50px; font-size: 0.85rem; font-weight: 600; margin-bottom: 20px; border: 1px solid rgba(0,192,135,0.2); }
.hero-content h1 { font-size: 3rem; font-weight: 800; line-height: 1.25; margin-bottom: 20px; }
.hero-content h1 .highlight { background: linear-gradient(135deg, var(--accent-green), var(--accent-gold)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero-content p { font-size: 1.1rem; color: var(--text-secondary); margin-bottom: 32px; max-width: 520px; }
.hero-btns { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-image { animation: fadeInUp 0.8s ease 0.2s both; display: flex; justify-content: center; }
.hero-image img { border-radius: var(--radius-lg); box-shadow: var(--shadow-lg), 0 0 40px rgba(0,192,135,0.06); max-width: 100%; }

/* === Stats Bar === */
.stats-bar { background: var(--bg-secondary); border-top: 1px solid var(--border-color); border-bottom: 1px solid var(--border-color); padding: 32px 0; }
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; text-align: center; }
.stat-item .stat-number { font-size: 2rem; font-weight: 800; color: var(--accent-green); margin-bottom: 4px; }
.stat-item .stat-number .gold { color: var(--accent-gold); }
.stat-item .stat-label { font-size: 0.9rem; color: var(--text-muted); }

/* === Features Section === */
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.feature-card { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 36px 28px; transition: all var(--transition-normal); position: relative; overflow: hidden; }
.feature-card::before { content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 3px; background: linear-gradient(90deg, var(--accent-green), var(--accent-gold)); transform: scaleX(0); transform-origin: left; transition: transform var(--transition-normal); }
.feature-card:hover::before { transform: scaleX(1); }
.feature-card:hover { background: var(--bg-card-hover); border-color: var(--border-light); transform: translateY(-4px); box-shadow: var(--shadow-md), var(--shadow-glow-green); }
.feature-icon { width: 56px; height: 56px; border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; margin-bottom: 20px; font-size: 1.5rem; }
.feature-icon.green { background: rgba(0,192,135,0.1); color: var(--accent-green); }
.feature-icon.gold { background: rgba(232,184,48,0.1); color: var(--accent-gold); }
.feature-icon.blue { background: rgba(30,144,255,0.1); color: #1e90ff; }
.feature-card h3 { font-size: 1.15rem; margin-bottom: 10px; }
.feature-card p { font-size: 0.9rem; color: var(--text-secondary); line-height: 1.6; }

/* === Services Section === */
.services-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.service-card { background: var(--bg-card); border-radius: var(--radius-md); padding: 32px 24px; border: 1px solid var(--border-color); transition: all var(--transition-normal); text-align: center; }
.service-card:hover { border-color: var(--accent-green); box-shadow: var(--shadow-glow-green); transform: translateY(-4px); }
.service-icon { width: 48px; height: 48px; border-radius: 50%; background: rgba(0,192,135,0.1); display: flex; align-items: center; justify-content: center; margin: 0 auto 16px; font-size: 1.3rem; }
.service-card h3 { font-size: 1.1rem; margin-bottom: 8px; }
.service-card p { font-size: 0.88rem; color: var(--text-secondary); }

/* === CTA Section === */
.cta { background: linear-gradient(135deg, var(--bg-secondary), var(--bg-card)); text-align: center; position: relative; overflow: hidden; }
.cta::before { content: ''; position: absolute; top: 0; left: 50%; transform: translateX(-50%); width: 500px; height: 500px; background: radial-gradient(circle, rgba(0,192,135,0.06), transparent 70%); pointer-events: none; }
.cta .container { position: relative; z-index: 1; }
.cta h2 { font-size: 2.2rem; font-weight: 700; margin-bottom: 16px; }
.cta p { color: var(--text-secondary); margin-bottom: 32px; font-size: 1.05rem; }

/* === Footer === */
.footer { background: var(--bg-secondary); border-top: 1px solid var(--border-color); padding: 56px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand h3 { font-size: 1.3rem; margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
.footer-brand p { font-size: 0.88rem; color: var(--text-muted); max-width: 300px; }
.footer-col h4 { font-size: 1rem; margin-bottom: 16px; color: var(--text-primary); }
.footer-col a { display: block; color: var(--text-muted); font-size: 0.88rem; margin-bottom: 10px; transition: color var(--transition-fast); }
.footer-col a:hover { color: var(--accent-green); }
.footer-bottom { border-top: 1px solid var(--border-color); padding-top: 20px; text-align: center; color: var(--text-muted); font-size: 0.85rem; }

/* === About Page === */
.about-hero { padding: 80px 0 40px; text-align: center; }
.about-hero h1 { font-size: 2.6rem; margin-bottom: 16px; }
.about-hero p { color: var(--text-secondary); max-width: 700px; margin: 0 auto; font-size: 1.05rem; }
.timeline { position: relative; padding: 40px 0; }
.timeline::before { content: ''; position: absolute; left: 50%; transform: translateX(-50%); top: 0; bottom: 0; width: 2px; background: linear-gradient(180deg, var(--accent-green), var(--accent-gold)); }
.timeline-item { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; margin-bottom: 48px; position: relative; }
.timeline-item:nth-child(even) .timeline-content { order: -1; text-align: right; }
.timeline-dot { width: 16px; height: 16px; background: var(--accent-green); border-radius: 50%; border: 3px solid var(--bg-primary); position: absolute; left: 50%; top: 50%; transform: translate(-50%,-50%); z-index: 1; }
.timeline-year { font-size: 1.5rem; font-weight: 700; color: var(--accent-green); margin-bottom: 8px; }
.timeline-content { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 24px; transition: all var(--transition-normal); }
.timeline-content:hover { border-color: var(--accent-green); box-shadow: var(--shadow-glow-green); }
.timeline-content h3 { font-size: 1.1rem; margin-bottom: 8px; }
.timeline-content p { font-size: 0.9rem; color: var(--text-secondary); }
.team-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.team-card { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 28px 20px; text-align: center; transition: all var(--transition-normal); }
.team-card:hover { transform: translateY(-4px); border-color: var(--accent-green); box-shadow: var(--shadow-glow-green); }
.team-card img { width: 80px; height: 80px; border-radius: 50%; margin: 0 auto 16px; border: 3px solid var(--accent-green); }
.team-card h3 { font-size: 1rem; margin-bottom: 4px; }
.team-card .role { font-size: 0.85rem; color: var(--accent-green); margin-bottom: 8px; }
.team-card p { font-size: 0.82rem; color: var(--text-muted); }
.compliance-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.compliance-item { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-sm); padding: 20px; display: flex; align-items: center; gap: 14px; transition: all var(--transition-normal); }
.compliance-item:hover { border-color: var(--accent-green); }
.compliance-icon { width: 44px; height: 44px; border-radius: var(--radius-sm); background: rgba(0,192,135,0.1); display: flex; align-items: center; justify-content: center; font-size: 1.2rem; color: var(--accent-green); flex-shrink: 0; }
.compliance-item h4 { font-size: 0.95rem; margin-bottom: 2px; }
.compliance-item p { font-size: 0.8rem; color: var(--text-muted); }

/* === FAQ Page === */
.faq-hero { padding: 80px 0 40px; text-align: center; }
.faq-hero h1 { font-size: 2.6rem; margin-bottom: 16px; }
.faq-hero p { color: var(--text-secondary); max-width: 600px; margin: 0 auto; }
.faq-search { max-width: 500px; margin: 24px auto 0; display: flex; gap: 10px; }
.faq-search input { flex: 1; padding: 12px 20px; border-radius: 50px; border: 1px solid var(--border-light); background: var(--bg-card); color: var(--text-primary); font-size: 0.95rem; outline: none; transition: border-color var(--transition-fast); }
.faq-search input:focus { border-color: var(--accent-green); }
.faq-categories { display: flex; gap: 12px; justify-content: center; margin-bottom: 40px; flex-wrap: wrap; }
.faq-cat { padding: 8px 20px; border-radius: 50px; border: 1px solid var(--border-light); background: var(--bg-card); color: var(--text-secondary); cursor: pointer; font-size: 0.9rem; transition: all var(--transition-fast); }
.faq-cat:hover, .faq-cat.active { background: var(--accent-green); color: #0d1b2a; border-color: var(--accent-green); }
.faq-group { margin-bottom: 40px; }
.faq-group h2 { font-size: 1.4rem; color: var(--accent-green); margin-bottom: 20px; padding-bottom: 10px; border-bottom: 1px solid var(--border-color); }
.faq-group details { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-sm); margin-bottom: 10px; overflow: hidden; transition: all var(--transition-fast); }
.faq-group details:hover { border-color: var(--border-light); }
.faq-group details[open] { border-color: var(--accent-green); box-shadow: var(--shadow-glow-green); }
.faq-group summary { padding: 16px 20px; cursor: pointer; font-weight: 600; font-size: 0.95rem; display: flex; justify-content: space-between; align-items: center; list-style: none; user-select: none; }
.faq-group summary::-webkit-details-marker { display: none; }
.faq-group summary::after { content: '+'; font-size: 1.2rem; color: var(--accent-green); transition: transform var(--transition-fast); font-weight: 400; }
.faq-group details[open] summary::after { content: '−'; transform: rotate(180deg); }
.faq-group .faq-answer { padding: 0 20px 20px; font-size: 0.9rem; color: var(--text-secondary); line-height: 1.7; }

/* === Contact Page === */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: start; }
.contact-info h3 { font-size: 1.3rem; margin-bottom: 20px; }
.contact-info-item { display: flex; gap: 14px; margin-bottom: 24px; }
.contact-info-icon { width: 44px; height: 44px; border-radius: 50%; background: rgba(0,192,135,0.1); display: flex; align-items: center; justify-content: center; flex-shrink: 0; color: var(--accent-green); font-size: 1.1rem; }
.contact-info-item h4 { font-size: 0.95rem; margin-bottom: 4px; }
.contact-info-item p { font-size: 0.88rem; color: var(--text-secondary); }
.contact-form { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 32px; }
.contact-form h3 { font-size: 1.3rem; margin-bottom: 20px; }
.form-group { margin-bottom: 18px; }
.form-group label { display: block; font-size: 0.88rem; color: var(--text-secondary); margin-bottom: 6px; font-weight: 500; }
.form-group input, .form-group select, .form-group textarea { width: 100%; padding: 12px 16px; border-radius: var(--radius-sm); border: 1px solid var(--border-light); background: var(--bg-secondary); color: var(--text-primary); font-size: 0.9rem; outline: none; font-family: inherit; transition: border-color var(--transition-fast); }
.form-group input:focus, .form-group select:focus, .form-group textarea:focus { border-color: var(--accent-green); }
.form-group textarea { resize: vertical; min-height: 120px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.social-links { display: flex; gap: 16px; margin-top: 24px; }
.social-link { width: 44px; height: 44px; border-radius: 50%; background: var(--bg-card); border: 1px solid var(--border-light); display: flex; align-items: center; justify-content: center; color: var(--text-secondary); font-size: 1.1rem; transition: all var(--transition-fast); }
.social-link:hover { background: var(--accent-green); color: #0d1b2a; border-color: var(--accent-green); }
.offices-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 24px; }
.office-card { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-sm); padding: 20px; text-align: center; transition: all var(--transition-normal); }
.office-card:hover { border-color: var(--accent-green); }
.office-card h4 { font-size: 0.95rem; margin-bottom: 6px; }
.office-card p { font-size: 0.82rem; color: var(--text-muted); }

/* === Animations === */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
.reveal { opacity: 0; transform: translateY(30px); transition: all 0.6s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* === Responsive === */
@media (max-width: 1024px) {
  .hero .container { grid-template-columns: 1fr; text-align: center; }
  .hero-content p { margin: 0 auto 32px; }
  .hero-btns { justify-content: center; }
  .hero-image { order: -1; }
  .hero-image img { max-width: 400px; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .services-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .team-grid { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
  .timeline-item { grid-template-columns: 1fr; text-align: left; }
  .timeline::before { left: 20px; }
  .timeline-dot { left: 20px; }
  .timeline-item:nth-child(even) .timeline-content { order: 0; text-align: left; }
  .compliance-grid { grid-template-columns: repeat(2, 1fr); }
  .offices-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-links { position: fixed; top: 0; right: -100%; width: 75%; max-width: 300px; height: 100vh; background: var(--bg-secondary); flex-direction: column; padding: 80px 24px 24px; gap: 20px; transition: right var(--transition-normal); z-index: 99; border-left: 1px solid var(--border-color); }
  .nav-links.active { right: 0; }
  .menu-toggle { display: flex; z-index: 100; }
  .hero-content h1 { font-size: 2rem; }
  .hero { min-height: auto; padding: 60px 0; }
  section { padding: 56px 0; }
  .section-header h2 { font-size: 1.7rem; }
  .features-grid { grid-template-columns: 1fr; }
  .services-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; gap: 20px; }
  .footer-grid { grid-template-columns: 1fr; }
  .team-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .compliance-grid { grid-template-columns: 1fr; }
  .offices-grid { grid-template-columns: 1fr; }
  .cta h2 { font-size: 1.6rem; }
}