/**
 * 现代化导航栏和页脚样式
 * 高端设计，符合现代Web设计趋势
 */

/* ========== CSS变量定义 ========== */
:root {
  /* 现代化配色方案 */
  --navbar-bg: rgba(255, 255, 255, 0.95);
  --navbar-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
  --navbar-border: rgba(255, 255, 255, 0.2);
  --navbar-text: #2d3748;
  --navbar-text-hover: #667eea;
  --navbar-brand-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  
  /* 页脚配色 */
  --footer-bg: rgba(255, 255, 255, 0.95);
  --footer-text: #2d3748;
  --footer-text-muted: #718096;
  --footer-accent: #667eea;
  --footer-border: rgba(0, 0, 0, 0.1);
  
  /* 动画变量 */
  --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-bounce: all 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  
  /* 阴影系统 */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07), 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1), 0 10px 10px rgba(0, 0, 0, 0.04);
}

/* 夜间模式变量 */
[data-theme="dark"] {
  --navbar-bg: rgba(26, 32, 44, 0.95);
  --navbar-text: #f7fafc;
  --navbar-text-hover: #90cdf4;
  --navbar-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
  --navbar-border: rgba(255, 255, 255, 0.1);
  
  /* 夜间模式页脚配色 */
  --footer-bg: rgba(26, 32, 44, 0.95);
  --footer-text: #f7fafc;
  --footer-text-muted: #a0aec0;
  --footer-accent: #90cdf4;
  --footer-border: rgba(255, 255, 255, 0.1);
}

/* ========== 导航栏现代化设计 ========== */
.navbar {
  background: var(--navbar-bg) !important;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--navbar-shadow);
  border-bottom: 1px solid var(--navbar-border);
  position: fixed !important;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1030;
  transition: var(--transition-smooth);
  padding: 0.75rem 0;
}

.navbar.scrolled {
  background: var(--navbar-bg) !important;
  box-shadow: var(--shadow-lg);
  padding: 0.5rem 0;
}

/* 品牌Logo现代化 */
.navbar-brand {
  font-weight: 700 !important;
  font-size: 1.5rem !important;
  background: var(--navbar-brand-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transition: var(--transition-smooth);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.navbar-brand:hover {
  transform: scale(1.05);
  filter: brightness(1.1);
}

.navbar-brand i {
  background: var(--navbar-brand-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-size: 1.3rem;
}

/* 导航链接现代化 */
.navbar-nav .nav-link {
  color: var(--navbar-text) !important;
  font-weight: 500;
  padding: 0.75rem 1rem !important;
  border-radius: 0;
  transition: var(--transition-smooth);
  position: relative;
  margin: 0 0.25rem;
  background: transparent !important;
  border: none !important;
}

.navbar-nav .nav-link:hover {
  color: var(--navbar-text-hover) !important;
  background: transparent !important;
  transform: none;
}

.navbar-nav .nav-link.active {
  color: var(--navbar-text-hover) !important;
  background: transparent !important;
  font-weight: 600;
}

/* 现代化下拉菜单 */
.navbar .dropdown-menu {
  background: var(--navbar-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--navbar-border);
  box-shadow: var(--shadow-xl);
  border-radius: 12px;
  padding: 0.5rem 0;
  margin-top: 0.5rem;
  min-width: 220px;
  animation: dropdownFadeIn 0.3s ease-out;
}

@keyframes dropdownFadeIn {
  from {
    opacity: 0;
    transform: translateY(-10px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.navbar .dropdown-item {
  color: var(--navbar-text);
  padding: 0.75rem 1.25rem;
  font-weight: 500;
  transition: var(--transition-smooth);
  border-radius: 8px;
  margin: 0 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.navbar .dropdown-item:hover {
  background: rgba(102, 126, 234, 0.1);
  color: var(--navbar-text-hover);
  transform: translateX(4px);
}

.navbar .dropdown-item img {
  width: 24px;
  height: 24px;
  border-radius: 6px;
  object-fit: cover;
}

/* 搜索按钮现代化 */
.btn-outline-light {
  border: 2px solid rgba(102, 126, 234, 0.3);
  color: var(--navbar-text-hover);
  background: transparent;
  border-radius: 10px;
  padding: 0.5rem 0.75rem;
  transition: var(--transition-smooth);
}

.btn-outline-light:hover {
  background: var(--navbar-text-hover);
  border-color: var(--navbar-text-hover);
  color: white;
  transform: scale(1.05);
  box-shadow: var(--shadow-md);
}

/* 主题切换按钮现代化 */
.theme-toggle {
  background: transparent !important;
  border: 2px solid rgba(102, 126, 234, 0.3) !important;
  color: var(--navbar-text-hover) !important;
  border-radius: 10px !important;
  padding: 0.5rem 0.75rem !important;
  transition: var(--transition-bounce) !important;
  font-weight: 500;
}

.theme-toggle:hover {
  background: var(--navbar-text-hover) !important;
  color: white !important;
  transform: rotate(180deg) scale(1.1);
  box-shadow: var(--shadow-md);
}

/* 移动端汉堡菜单 */
.navbar-toggler {
  border: none;
  padding: 0.5rem;
  border-radius: 8px;
  transition: var(--transition-smooth);
}

.navbar-toggler:focus {
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.25);
}

.navbar-toggler-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%2845, 55, 72, 1%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='m4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* ========== 页脚现代化设计 ========== */
.footer {
  background: var(--footer-bg) !important;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  color: var(--footer-text) !important;
  padding: 2rem 0 1rem 0 !important;
  margin-top: 2rem !important;
  position: relative;
  overflow: hidden;
  box-shadow: 0 -2px 20px rgba(0, 0, 0, 0.1);
  border-top: 1px solid var(--footer-border);
}

/* 页脚装饰性背景 */
.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #667eea, #764ba2, #f093fb, #f5576c, #4facfe, #00f2fe);
  background-size: 400% 400%;
  animation: gradientShift 8s ease infinite;
}

@keyframes gradientShift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

/* 页脚内容区域 */
.footer .container {
  position: relative;
  z-index: 2;
}

.footer h5 {
  color: var(--footer-text) !important;
  font-weight: 600;
  margin-bottom: 1.5rem;
  font-size: 1.25rem;
  position: relative;
  padding-bottom: 0.5rem;
}

.footer h5::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--footer-accent);
  border-radius: 2px;
}

/* 页脚链接现代化 */
.footer .list-unstyled li {
  margin-bottom: 0.75rem;
}

.footer .list-unstyled a {
  color: var(--footer-text-muted) !important;
  text-decoration: none;
  transition: var(--transition-smooth);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.25rem 0;
  border-radius: 4px;
}

.footer .list-unstyled a:hover {
  color: var(--footer-accent) !important;
  transform: translateX(8px);
  text-decoration: none;
}

.footer .list-unstyled a::before {
  content: '→';
  opacity: 0;
  transform: translateX(-10px);
  transition: var(--transition-smooth);
}

.footer .list-unstyled a:hover::before {
  opacity: 1;
  transform: translateX(0);
}

/* 联系信息美化 */
.footer .contact-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
  padding: 0.75rem;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 10px;
  border: 1px solid var(--footer-border);
  transition: var(--transition-smooth);
}

.footer .contact-info:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.footer .contact-info i {
  color: var(--footer-accent);
  font-size: 1.2rem;
  width: 24px;
  text-align: center;
}

/* 社交媒体图标 */
.footer .social-links {
  display: flex;
  gap: 1rem;
  margin-top: 1.5rem;
}

.footer .social-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid var(--footer-border);
  border-radius: 12px;
  color: var(--footer-text-muted);
  text-decoration: none;
  transition: var(--transition-bounce);
  font-size: 1.2rem;
}

.footer .social-link:hover {
  background: var(--footer-accent);
  color: white;
  transform: translateY(-4px) scale(1.1);
  box-shadow: var(--shadow-lg);
  text-decoration: none;
}

/* 页脚分割线 */
.footer hr {
  border: none;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--footer-border), transparent);
  margin: 1rem 0 0.5rem 0;
}

/* 版权信息 */
.footer .copyright {
  text-align: center;
  color: var(--footer-text-muted);
  font-size: 0.9rem;
  padding: 0.5rem 0;
  margin-top: 0.5rem;
}

/* ========== 响应式设计 ========== */

/* 平板端适配 */
@media (max-width: 991px) {
  .navbar-nav {
    background: var(--navbar-bg);
    border-radius: 12px;
    padding: 1rem;
    margin-top: 1rem;
    box-shadow: var(--shadow-lg);
  }
  
  .navbar-nav .nav-link {
    margin: 0.25rem 0;
  }
  
  .footer {
    padding: 3rem 0 1.5rem 0 !important;
  }
  
  .footer .social-links {
    justify-content: center;
  }
}

/* 移动端适配 */
@media (max-width: 767px) {
  .navbar {
    padding: 0.5rem 0;
  }
  
  .navbar-brand {
    font-size: 1.3rem !important;
  }
  
  .footer {
    padding: 2.5rem 0 1rem 0 !important;
    text-align: center;
  }
  
  .footer .row > div {
    margin-bottom: 2rem;
  }
  
  .footer h5::after {
    left: 50%;
    transform: translateX(-50%);
  }
  
  .footer .contact-info {
    justify-content: center;
  }
}

/* 超小屏幕适配 */
@media (max-width: 480px) {
  .navbar-brand {
    font-size: 1.1rem !important;
  }
  
  .navbar-nav .nav-link {
    padding: 0.5rem 0.75rem !important;
    font-size: 0.9rem;
  }
  
  .footer {
    padding: 2rem 0 1rem 0 !important;
  }
  
  .footer .social-link {
    width: 40px;
    height: 40px;
    font-size: 1rem;
  }
}

/* ========== 滚动指示器 ========== */
.scroll-indicator {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 3px;
  background: linear-gradient(90deg, #667eea, #764ba2);
  z-index: 1031;
  transition: width 0.1s ease;
}

/* ========== 返回顶部按钮 ========== */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  background: var(--navbar-brand-gradient);
  color: white;
  border: none;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: var(--transition-bounce);
  z-index: 1020;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-4px) scale(1.1);
  box-shadow: var(--shadow-xl);
  color: white;
}

/* ========== 加载动画 ========== */
.loading-spinner {
  display: inline-block;
  width: 16px;
  height: 16px;
  border: 2px solid rgba(102, 126, 234, 0.3);
  border-radius: 50%;
  border-top-color: var(--navbar-text-hover);
  animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ========== 无障碍支持 ========== */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  .back-to-top:hover {
    transform: none;
  }
  
  .theme-toggle:hover {
    transform: none;
  }
}

/* 高对比度模式 */
@media (prefers-contrast: high) {
  :root {
    --navbar-border: #000;
    --footer-border: #fff;
  }
  
  .navbar {
    border-bottom: 2px solid var(--navbar-border);
  }
}