/* 
 * 方案一：深邃极光 (Deep Aurora) 全局样式表
 * 融合了暗色科技背景、极光霓虹渐变和高对比度文本，完美体现安全、合规与权威。
 */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Syne:wght@700;800&display=swap');

:root {
  --bg-color: #030712;
  --card-bg: rgba(17, 24, 39, 0.7);
  --card-border: rgba(55, 65, 81, 0.5);
  --text-primary: #f9fafb;
  --text-secondary: #9ca3af;
  --primary: #2563eb;
  --primary-glow: rgba(37, 99, 235, 0.4);
  --accent-purple: #7c3aed;
  --accent-purple-glow: rgba(124, 58, 237, 0.4);
  --accent-green: #10b981;
  --accent-green-glow: rgba(16, 185, 129, 0.2);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-display: 'Syne', sans-serif;
  --ease-out: cubic-bezier(0.23, 1, 0.32, 1);
  --ease-in-out: cubic-bezier(0.77, 0, 0.175, 1);
}

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

body {
  background-color: var(--bg-color);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* 布局容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* 导航栏 */
header {
  border-bottom: 1px solid var(--card-border);
  background-color: rgba(3, 7, 18, 0.85);
  backdrop-filter: blur(12px);
  position: relative;
  z-index: 50;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 80px;
}

.logo {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--primary), var(--accent-purple));
  border-radius: 8px;
  display: inline-block;
  position: relative;
}

.logo-icon::after {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  right: 2px;
  bottom: 2px;
  background-color: var(--bg-color);
  border-radius: 6px;
}

.nav-links {
  display: flex;
  gap: 2rem;
  align-items: center;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.2s var(--ease-out);
}

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

/* 纯CSS语言切换下拉菜单 */
.lang-selector {
  position: relative;
  display: inline-block;
}

.lang-trigger {
  background: rgba(31, 41, 55, 0.6);
  border: 1px solid var(--card-border);
  color: var(--text-primary);
  padding: 0.5rem 1rem;
  border-radius: 9999px;
  font-size: 0.875rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.2s var(--ease-out);
}

.lang-trigger:hover {
  background: rgba(55, 65, 81, 0.8);
  border-color: var(--primary);
}

.lang-dropdown {
  position: absolute;
  right: 0;
  top: 100%;
  margin-top: 0.5rem;
  background: rgba(17, 24, 39, 0.95);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  width: 160px;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.5);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all 0.2s var(--ease-out);
  list-style: none;
  padding: 0.5rem 0;
}

.lang-selector:hover .lang-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-dropdown a {
  display: block;
  padding: 0.6rem 1rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  transition: all 0.2s var(--ease-out);
}

.lang-dropdown a:hover {
  background: rgba(31, 41, 55, 0.8);
  color: var(--text-primary);
}

/* 按钮样式 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s var(--ease-out);
  cursor: pointer;
  gap: 0.5rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--accent-purple));
  color: #ffffff;
  box-shadow: 0 4px 20px var(--primary-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 25px var(--accent-purple-glow);
}

.btn-secondary {
  background: rgba(31, 41, 55, 0.6);
  border: 1px solid var(--card-border);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background: rgba(55, 65, 81, 0.8);
  border-color: var(--primary);
  transform: translateY(-2px);
}

/* 底部 */
footer {
  background-color: #02040a;
  border-top: 1px solid var(--card-border);
  padding: 4rem 0 2rem;
  margin-top: 5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand p {
  color: var(--text-secondary);
  margin-top: 1rem;
  font-size: 0.9rem;
}

.footer-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  color: var(--text-primary);
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.75rem;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s var(--ease-out);
}

.footer-links a:hover {
  color: var(--text-primary);
}

.footer-info p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

/* 灰色Logo墙 */
.license-wall {
  border-top: 1px solid rgba(55, 65, 81, 0.3);
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 2rem;
}

.license-logos {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.license-logo {
  height: 32px;
  filter: grayscale(100%) opacity(0.4);
  transition: all 0.3s var(--ease-out);
}

.license-logo:hover {
  filter: grayscale(0%) opacity(0.8);
}

.copyright {
  color: rgba(156, 163, 175, 0.5);
  font-size: 0.8rem;
}

/* 面包屑导航 */
.breadcrumb-section {
  background: rgba(17, 24, 39, 0.4);
  border-bottom: 1px solid var(--card-border);
  padding: 1rem 0;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  list-style: none;
}

.breadcrumb a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s var(--ease-out);
}

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

.breadcrumb-separator {
  color: rgba(156, 163, 175, 0.4);
}

/* 卡片与网格通用样式 */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.glass-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 2rem;
  position: relative;
  overflow: hidden;
  transition: all 0.3s var(--ease-out);
}

.glass-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: 0 10px 30px rgba(37, 99, 235, 0.15);
}

.glass-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent-purple));
  opacity: 0;
  transition: opacity 0.3s var(--ease-out);
}

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

/* 响应式媒体查询 */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none; /* 移动端隐藏或简化 */
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .grid-2, .grid-3 {
    grid-template-columns: 1fr;
  }
  .grid-4 {
    grid-template-columns: 1fr;
  }
  .license-wall {
    flex-direction: column;
    align-items: flex-start;
    gap: 1.5rem;
  }
}