:root {
  --nav-height: 72px;
  --primary-bg: #0f172a; // 深蓝底色
  --glass-bg: rgba(15, 23, 42, 0.85);
  --accent-color: #3b82f6; // 科技蓝
  --accent-glow: 0 0 10px rgba(59, 130, 246, 0.7);
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --transition-speed: 0.25s;
}

/* 科技感导航栏 */
.tech-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--glass-bg);
  backdrop-filter: blur(12px) saturate(180%);
  display: flex;
  justify-content: space-around;
  align-items: center;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  z-index: 1000;
  box-shadow: 0 -2px 30px rgba(0, 0, 0, 0.3);
  padding: 0 16px;
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 25%;
  height: 100%;
  color: var(--text-secondary);
  text-decoration: none;
  position: relative;
  transition: all var(--transition-speed) ease;
  overflow: hidden;
  
  &::before {
    content: '';
    position: absolute;
    top: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 40px;
    background: var(--accent-color);
    border-radius: 50%;
    opacity: 0;
    transition: all var(--transition-speed) ease;
    filter: blur(8px);
  }
}

.nav-icon {
  font-size: 20px;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  margin-bottom: 4px;
  transition: all var(--transition-speed) ease;
  position: relative;
  z-index: 1;
  background: rgba(255, 255, 255, 0.05);
}

.nav-label {
  font-size: 12px;
  font-weight: 500;
  transition: all var(--transition-speed) ease;
  position: relative;
  z-index: 1;
}

/* 活动状态样式 */
.nav-item.active {
  color: var(--text-primary);
  
  .nav-icon {
    background: rgba(59, 130, 246, 0.2);
    box-shadow: 0 0 0 1px rgba(59, 130, 246, 0.3);
    transform: translateY(-6px);
    
    i {
      color: var(--accent-color);
      text-shadow: var(--accent-glow);
    }
  }
  
  .nav-label {
    transform: translateY(4px);
    font-weight: 600;
  }
  
  &::before {
    opacity: 0.3;
    top: -20px;
  }
}

/* 导航指示器 */
.nav-indicator {
  position: absolute;
  top: -12px;
  left: 0;
  height: 4px;
  background: var(--accent-color);
  border-radius: 2px;
  transition: all 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  box-shadow: var(--accent-glow);
  z-index: 2;
}

/* 悬停效果 */
@media (hover: hover) {
  .nav-item:hover:not(.active) {
    color: var(--text-primary);
    
    .nav-icon {
      transform: translateY(-2px);
      background: rgba(255, 255, 255, 0.1);
    }
  }
}

/* 点击反馈 */
.nav-item:active {
  transform: scale(0.96);
}