/* ========================================
   阿达加速器 - 主样式表
   ======================================== */

/* --- CSS Variables --- */
:root {
  --bg-primary: #0a0e17;
  --bg-secondary: #111827;
  --bg-card: #1a1f2e;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent: #3b82f6;
  --accent-light: #60a5fa;
  --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 50%, #06b6d4 100%);
  --border: #1e293b;
  --success: #10b981;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC',
    'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial,
    sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

ul {
  list-style: none;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Utilities --- */
.gradient-text {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #fff;
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(59, 130, 246, 0.6);
}

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

.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent-light);
}

.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 16px;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  text-align: center;
  max-width: 600px;
  margin: 0 auto 60px;
}

/* --- Navbar --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  padding: 16px 0;
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(10, 14, 23, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 10px 0;
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.4rem;
  font-weight: 700;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--accent-gradient);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  transition: var(--transition);
  position: relative;
}

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

.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::after {
  width: 100%;
}

/* --- Hero --- */
.hero {
  padding: 160px 0 100px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(
    ellipse at 30% 20%,
    rgba(59, 130, 246, 0.08) 0%,
    transparent 50%
  ),
  radial-gradient(
    ellipse at 70% 60%,
    rgba(139, 92, 246, 0.06) 0%,
    transparent 50%
  );
  pointer-events: none;
}

.hero .container {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-content h1 {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 24px;
}

.hero-content p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 36px;
  max-width: 480px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-stats {
  display: flex;
  gap: 40px;
  margin-top: 40px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}

.hero-stat h3 {
  font-size: 1.8rem;
  font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-stat span {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-graphic {
  width: 380px;
  height: 380px;
  border-radius: 50%;
  background: var(--accent-gradient);
  opacity: 0.1;
  filter: blur(80px);
  position: absolute;
}

.hero-card {
  position: relative;
  z-index: 1;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  width: 100%;
  max-width: 420px;
  box-shadow: var(--shadow);
}

.hero-card-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
}

.hero-card-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--success);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.4); }
  50% { opacity: 0.8; box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
}

.hero-card-title {
  font-size: 0.95rem;
  font-weight: 600;
}

.hero-card-speed {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 4px;
}

.hero-card-unit {
  font-size: 1rem;
  color: var(--text-muted);
}

.hero-card-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

.hero-card-list li {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.hero-card-list li span {
  color: var(--text-primary);
}

/* --- Features --- */
.features {
  padding: 100px 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 28px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent-gradient);
  opacity: 0;
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: var(--shadow);
}

.feature-card:hover::before {
  opacity: 1;
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-sm);
  background: rgba(59, 130, 246, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 10px;
}

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

/* --- Servers --- */
.servers {
  padding: 100px 0;
  background: var(--bg-secondary);
}

.servers-map {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 48px;
}

.server-node {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  transition: var(--transition);
  cursor: default;
}

.server-node:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.server-flag {
  font-size: 2.5rem;
  margin-bottom: 12px;
}

.server-node h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.server-node p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.server-badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 50px;
  font-size: 0.75rem;
  background: rgba(16, 185, 129, 0.1);
  color: var(--success);
  margin-top: 8px;
}

.servers-cta {
  text-align: center;
  color: var(--text-secondary);
  font-size: 1.05rem;
}

.servers-cta strong {
  color: var(--text-primary);
}

/* --- Pricing --- */
.pricing {
  padding: 100px 0;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 28px;
  transition: var(--transition);
  position: relative;
  display: flex;
  flex-direction: column;
}

.pricing-card.featured {
  border-color: var(--accent);
  transform: scale(1.03);
  background: linear-gradient(180deg, rgba(59, 130, 246, 0.06) 0%, var(--bg-card) 30%);
}

.pricing-card:hover {
  border-color: var(--accent);
}

.pricing-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-gradient);
  color: #fff;
  padding: 6px 20px;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 600;
}

.pricing-header {
  text-align: center;
  margin-bottom: 28px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--border);
}

.pricing-name {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.pricing-price {
  font-size: 3rem;
  font-weight: 800;
}

.pricing-price small {
  font-size: 1rem;
  font-weight: 400;
  color: var(--text-muted);
}

.pricing-period {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 4px;
}

.pricing-features {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 28px;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.pricing-features li::before {
  content: '✓';
  color: var(--success);
  font-weight: 700;
  flex-shrink: 0;
}

.pricing-card .btn {
  width: 100%;
}

/* --- Download --- */
.download {
  padding: 100px 0;
  background: var(--bg-secondary);
  position: relative;
  overflow: hidden;
}

.download::before {
  content: '';
  position: absolute;
  width: 500px;
  height: 500px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.08) 0%, transparent 70%);
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
}

.download-content {
  position: relative;
  z-index: 1;
  text-align: center;
}

.download-platforms {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 40px;
}

.platform-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 32px;
  display: flex;
  align-items: center;
  gap: 16px;
  transition: var(--transition);
  cursor: pointer;
}

.platform-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.platform-icon {
  font-size: 2rem;
}

.platform-info h4 {
  font-size: 0.95rem;
  font-weight: 600;
}

.platform-info span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* --- FAQ --- */
.faq {
  padding: 100px 0;
}

.faq-list {
  max-width: 760px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
}

.faq-item.active {
  border-color: var(--accent);
}

.faq-question {
  padding: 20px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  user-select: none;
}

.faq-icon {
  font-size: 1.2rem;
  transition: var(--transition);
  color: var(--text-muted);
  flex-shrink: 0;
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
  color: var(--accent);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
}

.faq-item.active .faq-answer {
  max-height: 300px;
}

.faq-answer p {
  padding: 0 24px 20px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --- CTA Banner --- */
.cta-banner {
  padding: 0 0 100px;
}

.cta-box {
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 56px 40px;
  text-align: center;
}

.cta-box h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.cta-box p {
  color: var(--text-secondary);
  margin-bottom: 28px;
  font-size: 1.05rem;
}

/* --- Footer --- */
.footer {
  padding: 60px 0 30px;
  border-top: 1px solid var(--border);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand .logo {
  margin-bottom: 16px;
}

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.9rem;
  max-width: 280px;
}

.footer-col h4 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col a {
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: var(--transition);
}

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

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* --- Scroll animations --- */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Mobile Menu --- */
.mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
  z-index: 1001;
}

.mobile-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-content p {
    max-width: 100%;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-stats {
    justify-content: center;
  }

  .hero-visual {
    order: -1;
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .servers-map {
    grid-template-columns: repeat(2, 1fr);
  }

  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
    margin: 0 auto;
  }

  .pricing-card.featured {
    transform: none;
  }

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

@media (max-width: 768px) {
  .section-title {
    font-size: 1.8rem;
  }

  .hero-content h1 {
    font-size: 2.2rem;
  }

  .hero-stats {
    gap: 24px;
  }

  .hero-stat h3 {
    font-size: 1.4rem;
  }

  .mobile-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: var(--bg-secondary);
    flex-direction: column;
    padding: 80px 32px 32px;
    gap: 24px;
    transition: var(--transition);
    border-left: 1px solid var(--border);
  }

  .nav-links.active {
    right: 0;
  }

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

  .servers-map {
    grid-template-columns: 1fr 1fr;
  }

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

  .footer-bottom {
    flex-direction: column;
    gap: 8px;
  }
}