/* ============================================
   币圈十大交易所app下载 - 主样式表
   配色：深色背景(#0a0e1a)+金色(#f0b90b)+渐变蓝(#1e3a5f)+白色
   ============================================ */

/* === CSS Variables === */
:root {
  --bg-primary: #0a0e1a;
  --bg-secondary: #111827;
  --bg-card: #1a1f35;
  --bg-card-hover: #222840;
  --gold: #f0b90b;
  --gold-hover: #fcd535;
  --gold-dark: #c99a08;
  --blue-gradient-start: #1e3a5f;
  --blue-gradient-end: #0f1d33;
  --accent-blue: #3b82f6;
  --text-primary: #ffffff;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --border-color: #2a3050;
  --success: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --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-gold: 0 4px 20px rgba(240,185,11,0.25);
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  --max-width: 1200px;
}

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

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

body {
  font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}

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

a:hover {
  color: var(--gold-hover);
}

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

ul, ol {
  list-style: none;
}

/* === Typography === */
h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  font-weight: 700;
}

h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--gold), #ffe082);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

h2 {
  font-size: clamp(1.5rem, 3.5vw, 2.2rem);
  margin-bottom: 1rem;
  color: var(--text-primary);
}

h3 {
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  margin-bottom: 0.5rem;
}

p {
  margin-bottom: 0.75rem;
  color: var(--text-secondary);
}

.section-title {
  text-align: center;
  margin-bottom: 0.5rem;
}

.section-subtitle {
  text-align: center;
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 3rem;
}

.gold-text {
  color: var(--gold);
}

/* === Container === */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* === Header & Navigation === */
header {
  background: rgba(10, 14, 26, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
  transition: box-shadow var(--transition-normal);
}

header.scrolled {
  box-shadow: var(--shadow-lg);
}

header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.brand {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--gold);
  letter-spacing: 0.5px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.brand-icon {
  font-size: 1.6rem;
}

nav ul {
  display: flex;
  gap: 6px;
}

nav ul li a {
  display: block;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  transition: all var(--transition-fast);
}

nav ul li a:hover,
nav ul li a.active {
  color: var(--gold);
  background: rgba(240, 185, 11, 0.08);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  flex-direction: column;
  gap: 5px;
}

.mobile-menu-btn span {
  display: block;
  width: 26px;
  height: 2.5px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

/* === Hero Section === */
#hero {
  background: linear-gradient(135deg, var(--bg-primary) 0%, var(--blue-gradient-start) 50%, var(--bg-primary) 100%);
  padding: 80px 0 60px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

#hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(ellipse at center, rgba(240,185,11,0.05) 0%, transparent 70%);
  animation: heroGlow 8s ease-in-out infinite;
}

@keyframes heroGlow {
  0%, 100% { transform: translate(0, 0); }
  50% { transform: translate(5%, 3%); }
}

#hero .container {
  position: relative;
  z-index: 1;
}

#hero h1 {
  margin-bottom: 1.2rem;
}

#hero .hero-desc {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 2rem;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 2rem;
}

.hero-stats {
  display: flex;
  gap: 40px;
  justify-content: center;
  margin-top: 3rem;
  flex-wrap: wrap;
}

.hero-stat-item {
  text-align: center;
}

.hero-stat-item .stat-number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--gold);
}

.hero-stat-item .stat-label {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* === Buttons === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: all var(--transition-normal);
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--gold), var(--gold-dark));
  color: #1a1a1a;
  box-shadow: var(--shadow-gold);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 30px rgba(240,185,11,0.4);
  color: #1a1a1a;
}

.btn-outline {
  background: transparent;
  color: var(--gold);
  border: 2px solid var(--gold);
}

.btn-outline:hover {
  background: rgba(240,185,11,0.1);
  color: var(--gold-hover);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.15rem;
  border-radius: var(--radius-lg);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.85rem;
}

.btn-block {
  width: 100%;
}

/* === Sections === */
section {
  padding: 70px 0;
}

section:nth-child(even) {
  background: var(--bg-secondary);
}

/* === Features Section === */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 0;
  background: var(--gold);
  transition: height var(--transition-slow);
}

.feature-card:hover::before {
  height: 100%;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--gold);
  background: var(--bg-card-hover);
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: rgba(240,185,11,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 16px;
}

.feature-card h3 {
  margin-bottom: 8px;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* === Table Styles === */
.table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  box-shadow: var(--shadow-md);
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 700px;
}

table thead {
  background: linear-gradient(135deg, var(--blue-gradient-start), var(--blue-gradient-end));
}

table thead th {
  padding: 16px;
  text-align: left;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-primary);
  border-bottom: 2px solid var(--gold);
  white-space: nowrap;
}

table tbody tr {
  transition: all var(--transition-fast);
  border-bottom: 1px solid var(--border-color);
}

table tbody tr:last-child {
  border-bottom: none;
}

table tbody tr:hover {
  background: rgba(240,185,11,0.05);
}

table tbody td {
  padding: 14px 16px;
  font-size: 0.93rem;
  color: var(--text-secondary);
  vertical-align: middle;
}

.rank-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  font-weight: 700;
  font-size: 0.85rem;
  background: rgba(240,185,11,0.15);
  color: var(--gold);
}

.rank-badge.top3 {
  background: var(--gold);
  color: #1a1a1a;
}

.rating {
  color: var(--gold);
  font-weight: 600;
}

.rating-stars {
  color: var(--gold);
  font-size: 0.9rem;
}

/* === Exchange Detail Cards === */
.exchange-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  margin-bottom: 24px;
  transition: all var(--transition-normal);
}

.exchange-card:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--gold);
}

.exchange-card-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
}

.exchange-card-logo {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-md);
  overflow: hidden;
  flex-shrink: 0;
}

.exchange-card-logo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.exchange-card-info h3 {
  font-size: 1.3rem;
  margin-bottom: 4px;
}

.exchange-card-info .exchange-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
}

.tag-recommend {
  background: rgba(240,185,11,0.15);
  color: var(--gold);
}

.tag-safe {
  background: rgba(16,185,129,0.15);
  color: var(--success);
}

.tag-hot {
  background: rgba(239,68,68,0.15);
  color: var(--danger);
}

.exchange-card-body {
  margin-bottom: 20px;
}

.exchange-card-body p {
  margin-bottom: 10px;
  color: var(--text-secondary);
}

.exchange-pros {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 12px 0;
}

.exchange-pro {
  background: rgba(59,130,246,0.08);
  color: var(--accent-blue);
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 0.82rem;
}

/* === CTA Section === */
#cta {
  background: linear-gradient(135deg, var(--blue-gradient-start), var(--bg-primary));
  text-align: center;
}

#cta h2 {
  margin-bottom: 16px;
}

#cta p {
  max-width: 600px;
  margin: 0 auto 2rem;
}

/* === FAQ Styles === */
.faq-list {
  max-width: 900px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  transition: all var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--gold);
}

.faq-item summary {
  padding: 18px 24px;
  cursor: pointer;
  font-weight: 600;
  font-size: 1.05rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
  color: var(--text-primary);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '+';
  font-size: 1.4rem;
  color: var(--gold);
  transition: transform var(--transition-fast);
}

.faq-item[open] summary::after {
  content: '−';
  transform: rotate(180deg);
}

.faq-item .faq-answer {
  padding: 0 24px 20px;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* === Timeline === */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  padding-left: 40px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 18px;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(to bottom, transparent, var(--gold), transparent);
}

.timeline-item {
  position: relative;
  margin-bottom: 36px;
  padding-left: 20px;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -29px;
  top: 5px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 12px rgba(240,185,11,0.5);
}

.timeline-year {
  font-weight: 800;
  color: var(--gold);
  font-size: 1.1rem;
  margin-bottom: 4px;
}

.timeline-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
}

.timeline-content h4 {
  margin-bottom: 6px;
}

.timeline-content p {
  color: var(--text-muted);
  margin-bottom: 0;
}

/* === Contact Form === */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.contact-info-item {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.contact-info-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: rgba(240,185,11,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
}

.contact-info-item h4 {
  margin-bottom: 4px;
  font-size: 1rem;
}

.contact-info-item p {
  color: var(--text-muted);
  font-size: 0.93rem;
  margin-bottom: 0;
}

.contact-form {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
}

.form-group {
  margin-bottom: 18px;
}

.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 6px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color var(--transition-fast);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--gold);
  box-shadow: 0 0 0 3px rgba(240,185,11,0.1);
}

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

/* === About Page === */
.about-hero {
  text-align: center;
  padding: 60px 0 40px;
}

.about-mission {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin: 40px 0;
}

.mission-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px;
  text-align: center;
  transition: all var(--transition-normal);
}

.mission-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.mission-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.why-choose-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.why-choose-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: center;
  transition: all var(--transition-normal);
}

.why-choose-item:hover {
  transform: translateY(-3px);
  border-color: var(--gold);
}

/* === Social Media === */
.social-links {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: 0.9rem;
  transition: all var(--transition-fast);
}

.social-link:hover {
  border-color: var(--gold);
  color: var(--gold);
  transform: translateY(-2px);
}

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

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

/* === Footer === */
footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 50px 0 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
  margin-bottom: 30px;
}

.footer-col h4 {
  color: var(--text-primary);
  margin-bottom: 16px;
  font-size: 1.05rem;
}

.footer-col p,
.footer-col a {
  color: var(--text-muted);
  font-size: 0.9rem;
  display: block;
  margin-bottom: 8px;
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 20px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-bottom p {
  margin-bottom: 0;
}

/* === Breadcrumb === */
.breadcrumb {
  padding: 16px 0;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
}

.breadcrumb ol {
  display: flex;
  gap: 8px;
  align-items: center;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.breadcrumb ol li:not(:last-child)::after {
  content: '/';
  margin-left: 8px;
}

.breadcrumb a {
  color: var(--text-muted);
}

.breadcrumb a:hover {
  color: var(--gold);
}

.breadcrumb .current {
  color: var(--gold);
}

/* === Beginner Guide === */
.guide-steps {
  max-width: 700px;
  margin: 0 auto;
}

.guide-step {
  display: flex;
  gap: 16px;
  margin-bottom: 28px;
}

.guide-step-number {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gold);
  color: #1a1a1a;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.guide-step-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  flex: 1;
}

.guide-step-content h4 {
  margin-bottom: 6px;
}

.guide-step-content p {
  margin-bottom: 0;
  color: var(--text-muted);
}

/* === Responsive === */
@media (max-width: 1024px) {
  .container {
    padding: 0 24px;
  }
  
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  header .container {
    height: 60px;
  }

  .mobile-menu-btn {
    display: flex;
  }

  nav {
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    background: rgba(10,14,26,0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal);
  }

  nav.active {
    max-height: 400px;
  }

  nav ul {
    flex-direction: column;
    padding: 16px 24px;
    gap: 4px;
  }

  nav ul li a {
    padding: 12px 16px;
    font-size: 1rem;
  }

  #hero {
    padding: 50px 0 40px;
  }

  .hero-stats {
    gap: 20px;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  section {
    padding: 50px 0;
  }

  table {
    min-width: 600px;
  }

  .exchange-card-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .contact-form {
    padding: 24px;
  }
}

@media (max-width: 480px) {
  .hero-cta {
    flex-direction: column;
  }

  .btn-lg {
    width: 100%;
  }

  .timeline {
    padding-left: 28px;
  }

  .timeline::before {
    left: 12px;
  }

  .timeline-item::before {
    left: -23px;
    width: 12px;
    height: 12px;
  }
}