/* ==============================================================================
   光年VPN (LightYear VPN - guangnianvpn.my) 官方设计系统
   视觉规范: 深曜石黑 (Deep Obsidian) + 极光紫 (Aurora Violet) + 电竞翡翠绿 (Gaming Emerald)
   纯原生 CSS3 架构，零庞大依赖，秒级渲染，支持桌面端与移动端完美自适应
============================================================================== */

:root {
  --bg-deep: #070a12;
  --bg-surface: #0c1220;
  --bg-card: rgba(15, 23, 42, 0.72);
  --bg-card-hover: rgba(22, 33, 58, 0.85);
  
  --violet-primary: #a855f7;
  --violet-light: #c084fc;
  --violet-glow: rgba(168, 85, 247, 0.28);
  
  --emerald-primary: #10b981;
  --emerald-light: #34d399;
  --emerald-glow: rgba(16, 185, 129, 0.28);
  
  --cyan-accent: #06b6d4;
  --amber-accent: #f59e0b;
  --rose-accent: #f43f5e;
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(168, 85, 247, 0.35);
  --border-emerald: rgba(16, 185, 129, 0.35);
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --container-max: 1200px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  background-color: var(--bg-deep);
  color: var(--text-main);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  background: 
    radial-gradient(circle at 15% 10%, rgba(168, 85, 247, 0.12) 0%, transparent 45%),
    radial-gradient(circle at 85% 30%, rgba(16, 185, 129, 0.09) 0%, transparent 40%),
    radial-gradient(circle at 50% 85%, rgba(6, 182, 212, 0.08) 0%, transparent 50%),
    var(--bg-deep);
  background-attachment: fixed;
  overflow-x: hidden;
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
  transition: all 0.2s ease;
}

/* 布局容器 */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

/* 顶部导航栏 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  background: rgba(7, 10, 18, 0.82);
  border-bottom: 1px solid var(--border-subtle);
  transition: all 0.3s ease;
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: #ffffff;
}

.brand-icon-box {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--violet-primary), var(--emerald-primary));
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 15px rgba(168, 85, 247, 0.4);
}

.brand-icon-box svg {
  width: 20px;
  height: 20px;
  fill: #ffffff;
}

.brand-text-en {
  font-size: 11px;
  letter-spacing: 1.5px;
  color: var(--emerald-light);
  font-weight: 600;
  display: block;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-link {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  padding: 6px 0;
}

.nav-link:hover,
.nav-link.active {
  color: #ffffff;
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--violet-primary), var(--emerald-primary));
  border-radius: 2px;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* 极客发光按钮 */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--violet-primary) 0%, #7c3aed 50%, var(--emerald-primary) 100%);
  color: #ffffff;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 18px var(--violet-glow);
  transition: all 0.25s ease;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 25px rgba(168, 85, 247, 0.45), 0 0 15px var(--emerald-glow);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-main);
  border: 1px solid var(--border-subtle);
  cursor: pointer;
  transition: all 0.25s ease;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.2);
  color: #ffffff;
}

.btn-emerald {
  background: linear-gradient(135deg, var(--emerald-primary), #059669);
  color: #ffffff;
  box-shadow: 0 4px 18px var(--emerald-glow);
}

.btn-emerald:hover {
  box-shadow: 0 6px 25px rgba(16, 185, 129, 0.45);
}

/* 霓虹徽章与文本强调 */
.badge-neon {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: 600;
  font-family: var(--font-mono);
  background: rgba(168, 85, 247, 0.12);
  border: 1px solid var(--border-glow);
  color: var(--violet-light);
}

.badge-emerald {
  background: rgba(16, 185, 129, 0.12);
  border-color: var(--border-emerald);
  color: var(--emerald-light);
}

.gradient-text {
  background: linear-gradient(135deg, #ffffff 30%, var(--violet-light) 75%, var(--emerald-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gradient-text-emerald {
  background: linear-gradient(135deg, #ffffff 40%, var(--emerald-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* 玻璃拟态卡片 */
.glass-card {
  background: var(--bg-card);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 30px;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
}

.glass-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-glow);
  transform: translateY(-4px);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.4), 0 0 20px var(--violet-glow);
}

/* 页面公共区域间距 */
.section-py {
  padding: 80px 0;
}

.section-head {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 56px;
}

.section-title {
  font-size: 36px;
  font-weight: 800;
  letter-spacing: -0.8px;
  margin-top: 14px;
  margin-bottom: 16px;
}

.section-subtitle {
  font-size: 16px;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 页脚架构 */
.site-footer {
  background: #05070c;
  border-top: 1px solid var(--border-subtle);
  padding: 64px 0 32px;
  margin-top: 80px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 56px;
}

.footer-brand p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
  margin-top: 16px;
  max-width: 360px;
}

.footer-col h4 {
  font-size: 15px;
  font-weight: 600;
  color: #ffffff;
  margin-bottom: 20px;
  letter-spacing: 0.5px;
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col a {
  font-size: 14px;
  color: var(--text-muted);
}

.footer-col a:hover {
  color: var(--violet-light);
  transform: translateX(3px);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 13px;
  color: var(--text-dim);
}

.footer-badges {
  display: flex;
  align-items: center;
  gap: 14px;
}

.footer-badge-pill {
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-subtle);
  font-size: 12px;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* 移动端菜单控制 */
.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: #ffffff;
  cursor: pointer;
  padding: 8px;
}

@media (max-width: 900px) {
  .nav-menu {
    display: none;
  }
  .nav-menu.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 72px;
    left: 0;
    width: 100%;
    background: #090d18;
    border-bottom: 1px solid var(--border-subtle);
    padding: 24px;
    gap: 18px;
  }
  .mobile-toggle {
    display: block;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 36px;
  }
  .section-title {
    font-size: 28px;
  }
}

@media (max-width: 600px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .nav-actions .btn-secondary {
    display: none;
  }
}