/* ===== CSS 变量定义 ===== */
:root {
  /* 颜色系统 */
  --background-color: #0a0a0f;
  --glass-background: rgba(17, 24, 39, 0.4);
  --glass-border: rgba(148, 163, 184, 0.2);
  --primary-text-color: #e5e7eb;
  --secondary-text-color: #9ca3af;
  --accent-glow-color: #00d4ff;
  --accent-purple: #8b5cf6;
  --accent-pink: #ec4899;
  
  /* 字体系统 */
  --font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-family-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
  
  /* 间距系统 */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  
  /* 圆角系统 */
  --radius-sm: 0.5rem;
  --radius-md: 1rem;
  --radius-lg: 1.5rem;
  
  /* 阴影系统 */
  --shadow-glow: 0 0 20px rgba(0, 212, 255, 0.3);
  --shadow-glass: 0 8px 32px rgba(0, 0, 0, 0.3);
  --shadow-card: 0 4px 16px rgba(0, 0, 0, 0.2);
}

/* ===== 基础重置和全局样式 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family-base);
  background-color: var(--background-color);
  color: var(--primary-text-color);
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
}

/* ===== 动态极光背景 ===== */
.aurora-background {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  overflow: hidden;
}

.aurora-layer {
  position: absolute;
  width: 200%;
  height: 200%;
  background: linear-gradient(45deg, 
    rgba(0, 212, 255, 0.1) 0%,
    rgba(139, 92, 246, 0.1) 25%,
    rgba(236, 72, 153, 0.1) 50%,
    rgba(0, 212, 255, 0.1) 75%,
    rgba(139, 92, 246, 0.1) 100%
  );
  animation: aurora-flow 20s ease-in-out infinite;
}

.aurora-layer-1 {
  top: -50%;
  left: -50%;
  animation-delay: 0s;
  animation-duration: 25s;
}

.aurora-layer-2 {
  top: -30%;
  left: -30%;
  animation-delay: -8s;
  animation-duration: 30s;
  background: linear-gradient(-45deg, 
    rgba(139, 92, 246, 0.08) 0%,
    rgba(236, 72, 153, 0.08) 33%,
    rgba(0, 212, 255, 0.08) 66%,
    rgba(139, 92, 246, 0.08) 100%
  );
}

.aurora-layer-3 {
  top: -70%;
  left: -70%;
  animation-delay: -15s;
  animation-duration: 35s;
  background: radial-gradient(ellipse at center,
    rgba(0, 212, 255, 0.05) 0%,
    rgba(139, 92, 246, 0.05) 50%,
    transparent 100%
  );
}

@keyframes aurora-flow {
  0%, 100% {
    transform: translate(-50%, -50%) rotate(0deg) scale(1);
  }
  25% {
    transform: translate(-45%, -55%) rotate(90deg) scale(1.1);
  }
  50% {
    transform: translate(-55%, -45%) rotate(180deg) scale(0.9);
  }
  75% {
    transform: translate(-50%, -50%) rotate(270deg) scale(1.05);
  }
}

/* ===== 玻璃拟态容器 ===== */
.glass-container {
  background: var(--glass-background);
  backdrop-filter: blur(15px);
  -webkit-backdrop-filter: blur(15px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-glass);
  position: relative;
}

.glass-container::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(135deg, 
    rgba(255, 255, 255, 0.1) 0%,
    rgba(255, 255, 255, 0.05) 50%,
    rgba(255, 255, 255, 0.1) 100%
  );
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask-composite: xor;
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  pointer-events: none;
}

/* ===== 主容器布局 ===== */
.main-container {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
  z-index: 1;
}

.main-content {
  flex: 1;
  padding: var(--spacing-lg);
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

/* ===== 页头导航样式 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: var(--spacing-md) var(--spacing-lg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-md) var(--spacing-lg);
  max-width: 1200px;
  margin: 0 auto;
}

.nav-brand .brand-link {
  text-decoration: none;
  color: inherit;
}

.brand-title {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent-glow-color), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.25rem;
  transition: all 0.3s ease;
}

.brand-title:hover {
  text-shadow: 0 0 20px rgba(0, 212, 255, 0.5);
  transform: translateY(-1px);
}

.brand-subtitle {
  font-size: 0.875rem;
  color: var(--secondary-text-color);
  margin: 0;
}

.desktop-nav {
  display: flex;
  gap: var(--spacing-lg);
}

.nav-link {
  position: relative;
  text-decoration: none;
  color: var(--primary-text-color);
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  transition: all 0.3s ease;
  overflow: hidden;
}

.nav-link::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, 
    transparent, 
    rgba(0, 212, 255, 0.2), 
    transparent
  );
  transition: left 0.5s ease;
}

.nav-link:hover::before {
  left: 100%;
}

.nav-link:hover,
.nav-link.active {
  color: var(--accent-glow-color);
  text-shadow: 0 0 10px rgba(0, 212, 255, 0.5);
  transform: translateY(-1px);
}

.nav-link.active {
  background: rgba(0, 212, 255, 0.1);
  border: 1px solid rgba(0, 212, 255, 0.3);
}

/* ===== 移动端导航 ===== */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
  gap: 4px;
}

.hamburger-line {
  width: 24px;
  height: 2px;
  background: var(--primary-text-color);
  transition: all 0.3s ease;
  border-radius: 2px;
}

.mobile-nav-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(10px);
  z-index: 200;
  display: none;
  align-items: center;
  justify-content: center;
}

.mobile-nav-content {
  width: 90%;
  max-width: 400px;
  padding: var(--spacing-xl);
  position: relative;
}

.mobile-nav-close {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.close-line {
  position: absolute;
  width: 20px;
  height: 2px;
  background: var(--primary-text-color);
  border-radius: 2px;
}

.close-line:first-child {
  transform: rotate(45deg);
}

.close-line:last-child {
  transform: rotate(-45deg);
}

.mobile-nav-menu {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  margin-top: var(--spacing-xl);
}

.mobile-nav-link {
  text-decoration: none;
  color: var(--primary-text-color);
  font-size: 1.25rem;
  font-weight: 500;
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  text-align: center;
  transition: all 0.3s ease;
  border: 1px solid transparent;
}

.mobile-nav-link:hover,
.mobile-nav-link.active {
  color: var(--accent-glow-color);
  background: rgba(0, 212, 255, 0.1);
  border-color: rgba(0, 212, 255, 0.3);
  text-shadow: 0 0 10px rgba(0, 212, 255, 0.5);
}

/* ===== 响应式设计 ===== */
@media (max-width: 768px) {
  .desktop-nav {
    display: none;
  }
  
  .mobile-menu-toggle {
    display: flex;
  }
  
  .main-content {
    padding: var(--spacing-md);
  }
  
  .navbar {
    padding: var(--spacing-sm) var(--spacing-md);
  }
  
  .brand-title {
    font-size: 1.25rem;
  }
  
  .brand-subtitle {
    font-size: 0.75rem;
  }
}

@media (max-width: 480px) {
  .site-header {
    padding: var(--spacing-sm);
  }
  
  .main-content {
    padding: var(--spacing-sm);
  }
}