:root {
  --bg-dark: #0a1020;
  --bg-card: #101a30;
  --bg-section: #0d1425;
  --primary: #3b82f6;
  --accent: #60a5fa;
  --gradient-main: linear-gradient(135deg, #3b82f6 0%, #60a5fa 100%);
  --gradient-hero: linear-gradient(160deg, #0a1020 0%, #0f1a3a 50%, #0d1425 100%);
  --text-primary: #eff6ff;
  --text-secondary: #93c5fd;
  --text-muted: #5b7ba8;
  --border-color: rgba(59, 130, 246, 0.22);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --max-width: 1280px;
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}
a {
  color: inherit;
  text-decoration: none;
  transition: color 0.3s;
}
a:hover {
  color: var(--accent);
}
img {
  max-width: 100%;
  height: auto;
  display: block;
}
ul,
ol {
  list-style: none;
}
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(10, 16, 32, 0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 800;
}
.logo img {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
}
.logo-text {
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.main-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}
.main-nav a {
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all 0.3s;
  white-space: nowrap;
}
.main-nav a:hover,
.main-nav a.active {
  color: var(--text-primary);
  background: rgba(59, 130, 246, 0.14);
}
.main-nav a.active {
  color: var(--accent);
}
.mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.mobile-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
}
.section {
  padding: 80px 0;
}
.breadcrumb {
  padding: 100px 0 0;
  font-size: 13px;
  color: var(--text-muted);
}
.breadcrumb a {
  color: var(--text-secondary);
}
.breadcrumb span {
  margin: 0 8px;
}
.site-footer {
  background: var(--bg-section);
  border-top: 1px solid var(--border-color);
  padding: 60px 0 0;
  margin-top: 80px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}
.footer-brand p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 12px;
  line-height: 1.8;
}
.footer-col h4 {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 16px;
}
.footer-col a {
  display: block;
  font-size: 13px;
  color: var(--text-secondary);
  padding: 5px 0;
}
.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding: 20px 0;
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-muted);
}
.page-hero {
  padding: 120px 0 40px;
  background: var(--gradient-hero);
  text-align: center;
}
.page-hero h1 {
  font-size: 40px;
  font-weight: 900;
  letter-spacing: -1px;
  margin-bottom: 16px;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.page-hero p {
  font-size: 16px;
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto;
  line-height: 1.8;
}
.faq-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 48px;
}
.faq-sidebar {
  position: sticky;
  top: 100px;
  align-self: start;
}
.faq-sidebar h2 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 16px;
}
.faq-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.faq-nav a {
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--text-secondary);
  transition: all 0.3s;
  border-left: 2px solid transparent;
}
.faq-nav a:hover,
.faq-nav a.active {
  color: var(--accent);
  background: rgba(59, 130, 246, 0.08);
  border-left-color: var(--accent);
}
.faq-content h2 {
  font-size: 22px;
  font-weight: 800;
  margin: 40px 0 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}
.faq-content h2:first-child {
  margin-top: 0;
}
.faq-item {
  padding: 20px 24px;
  margin-bottom: 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  transition: all 0.3s;
}
.faq-item:hover {
  border-color: rgba(59, 130, 246, 0.4);
}
.faq-item h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 8px;
}
.faq-item p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
}
.faq-item a {
  color: var(--accent);
  text-decoration: underline;
}
.float-dl {
  position: fixed;
  left: 12px;
  right: 12px;
  bottom: 12px;
  z-index: 998;
  display: none;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  background: var(--bg-card);
  border: 1.5px solid var(--border-color);
  border-radius: 16px;
  box-shadow:
    0 12px 40px rgba(0, 0, 0, 0.55),
    0 0 30px var(--shadow-glow);
  transform: translateY(140%);
  transition: transform 0.45s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.float-dl.show {
  display: flex;
  transform: translateY(0);
}
.float-dl-close {
  position: absolute;
  top: -9px;
  right: -9px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: none;
  background: rgba(0, 0, 0, 0.8);
  color: #fff;
  font-size: 11px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
  padding: 0;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
}
.float-dl-icon {
  width: 42px;
  height: 42px;
  flex-shrink: 0;
  border-radius: 12px;
  background: var(--gradient-main);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.3);
}
.float-dl-text {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  line-height: 1.3;
}
.float-dl-text strong {
  font-size: 13.5px;
  font-weight: 700;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.float-dl-text span {
  font-size: 11px;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.float-dl-btn {
  flex-shrink: 0;
  padding: 10px 18px;
  border-radius: 11px;
  font-size: 13px;
  font-weight: 800;
  color: #fff;
  background: var(--gradient-main);
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.4);
  transition: transform 0.2s;
  white-space: nowrap;
}
.float-dl-btn:active {
  transform: scale(0.95);
}
@media (min-width: 769px) {
  .float-dl {
    display: none !important;
  }
}
@media (max-width: 768px) {
  .header-inner {
    height: 58px;
  }
  .main-nav {
    display: none;
    position: absolute;
    top: 58px;
    left: 0;
    right: 0;
    background: rgba(10, 16, 32, 0.98);
    flex-direction: column;
    padding: 16px 24px;
    border-bottom: 1px solid var(--border-color);
    gap: 4px;
  }
  .main-nav.open {
    display: flex;
  }
  .mobile-toggle {
    display: flex;
  }
  .site-footer {
    padding: 32px 0 0;
    margin-top: 44px;
  }
  .footer-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 18px 10px;
    margin-bottom: 20px;
  }
  .footer-brand {
    grid-column: 1/-1;
  }
  .footer-brand .logo {
    font-size: 16px;
    gap: 8px;
  }
  .footer-brand .logo img {
    width: 28px;
    height: 28px;
  }
  .footer-brand p {
    font-size: 11.5px;
    line-height: 1.6;
    margin-top: 6px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }
  .footer-col h4 {
    font-size: 12px;
    margin-bottom: 8px;
  }
  .footer-col a {
    font-size: 11.5px;
    padding: 3px 0;
    line-height: 1.4;
  }
  .footer-bottom {
    padding: 14px 0 88px;
    font-size: 10.5px;
    gap: 5px;
    flex-direction: column;
    text-align: center;
    line-height: 1.5;
  }
  .section {
    padding: 44px 0;
  }
  .breadcrumb {
    padding-top: 80px;
  }
  .page-hero {
    padding: 96px 0 26px;
  }
  .page-hero h1 {
    font-size: 26px;
    margin-bottom: 10px;
  }
  .page-hero p {
    font-size: 14px;
  }
  .faq-layout {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .faq-sidebar {
    position: static;
  }
  .faq-sidebar h2 {
    font-size: 14px;
    margin-bottom: 10px;
  }
  .faq-nav {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 6px;
  }
  .faq-nav a {
    padding: 6px 12px;
    font-size: 12.5px;
    border-left: none;
    border: 1px solid var(--border-color);
    border-radius: 100px;
    background: var(--bg-card);
  }
  .faq-nav a.active {
    background: rgba(59, 130, 246, 0.16);
    border-color: var(--primary);
  }
  .faq-content h2 {
    font-size: 18px;
    margin: 28px 0 14px;
    padding-bottom: 9px;
  }
  .faq-item {
    padding: 14px 16px;
    border-radius: 12px;
    margin-bottom: 10px;
  }
  .faq-item h3 {
    font-size: 14px;
    margin-bottom: 6px;
  }
  .faq-item p {
    font-size: 12.5px;
    line-height: 1.7;
  }
}
@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }
  .faq-item {
    padding: 12px 14px;
  }
}
@media (max-width: 380px) {
  .float-dl {
    padding: 10px;
    gap: 9px;
    left: 8px;
    right: 8px;
    bottom: 8px;
  }
  .float-dl-icon {
    width: 36px;
    height: 36px;
    font-size: 18px;
    border-radius: 10px;
  }
  .float-dl-text strong {
    font-size: 12.5px;
  }
  .float-dl-text span {
    font-size: 10px;
  }
  .float-dl-btn {
    padding: 9px 14px;
    font-size: 12px;
  }
}