/* =============================================
   导航样式 - nav.css
   功能：顶部导航、面包屑、分页、移动端菜单
   ============================================= */

/* 顶部导航栏 */
.header {
  background-color: var(--primary);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0,0,0,0.15);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-white);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.logo a {
  color: var(--text-white);
  display: flex;
  align-items: center;
}

.logo a:hover {
  color: var(--secondary);
}

/* 导航菜单 */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 0;
}

.nav-menu li {
  position: relative;
}

.nav-menu li a {
  display: block;
  padding: 0 18px;
  color: var(--text-white);
  font-size: 14px;
  font-weight: 500;
  line-height: 70px;
  transition: all 0.3s ease;
  white-space: nowrap;
}

.nav-menu li a:hover,
.nav-menu li a.active {
  color: var(--secondary);
  background-color: rgba(255,107,107,0.1);
}

/* 下拉菜单 */
.nav-menu li .dropdown {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background-color: var(--primary);
  min-width: 200px;
  box-shadow: 0 8px 20px rgba(0,0,0,0.2);
  border-top: 2px solid var(--secondary);
}

.nav-menu li .dropdown li a {
  line-height: 48px;
  padding: 0 20px;
  border-bottom: 1px solid rgba(255,255,255,0.05);
}

.nav-menu li .dropdown li a:hover {
  background-color: rgba(255,107,107,0.15);
}

.nav-menu li:hover .dropdown {
  display: block;
}

/* 移动端菜单按钮 */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
  background: none;
  border: none;
}

.mobile-menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--text-white);
  transition: all 0.3s ease;
}

/* 面包屑导航 */
.breadcrumb {
  background-color: #e8e8f0;
  padding: 12px 0;
  font-size: 13px;
  color: var(--text-muted);
}

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

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

.breadcrumb .sep {
  margin: 0 8px;
  color: #aaa;
}

.breadcrumb .current {
  color: var(--text-dark);
}

/* 分页 */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 6px;
  margin: 40px 0;
  flex-wrap: wrap;
}

.pagination a,
.pagination span {
  display: inline-block;
  padding: 8px 14px;
  border: 1px solid var(--border-color);
  color: var(--text-dark);
  font-size: 14px;
  border-radius: 4px;
  transition: all 0.3s ease;
}

.pagination a:hover {
  background-color: var(--secondary);
  color: var(--text-white);
  border-color: var(--secondary);
}

.pagination .current {
  background-color: var(--secondary);
  color: var(--text-white);
  border-color: var(--secondary);
}

.pagination .prev,
.pagination .next {
  font-weight: 500;
}

/* 返回顶部 */
.back-to-top {
  position: fixed;
  bottom: 40px;
  right: 40px;
  width: 44px;
  height: 44px;
  background-color: var(--secondary);
  color: var(--text-white);
  border: none;
  border-radius: 4px;
  cursor: pointer;
  font-size: 18px;
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.back-to-top:hover {
  background-color: #e05555;
}

/* 平板端导航 */
@media screen and (max-width: 1023px) {
  .nav-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background-color: var(--primary);
    flex-direction: column;
    align-items: stretch;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
    box-shadow: 0 8px 20px rgba(0,0,0,0.2);
  }
  
  .nav-menu.open {
    max-height: 500px;
    overflow-y: auto;
  }
  
  .nav-menu li a {
    line-height: 48px;
    border-bottom: 1px solid rgba(255,255,255,0.05);
  }
  
  .nav-menu li .dropdown {
    position: static;
    display: none;
    box-shadow: none;
    border-top: none;
    background-color: rgba(0,0,0,0.15);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    min-width: auto;
  }
  
  .nav-menu li.dropdown-open .dropdown {
    display: block;
    max-height: 300px;
  }
  
  .mobile-menu-toggle {
    display: flex;
  }
  
  .header-inner {
    height: 60px;
  }
  
  .logo {
    font-size: 16px;
  }
}

/* 手机端 */
@media screen and (max-width: 767px) {
  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
  }
  
  .breadcrumb {
    font-size: 12px;
  }
}