/* ============================================
   文玩核桃网站 - 通用组件样式
   导航栏、面包屑、页脚、返回顶部、加载动画、模态框
   ============================================ */

/* ===== 导航栏 ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: linear-gradient(135deg, var(--color-ink), #3a3a3a);
  border-bottom: 3px solid var(--color-primary);
  box-shadow: var(--shadow-lg);
}

.navbar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-lg);
  max-width: var(--container-max);
  margin: 0 auto;
  height: 64px;
}

.navbar__brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  color: var(--color-gold);
  font-family: var(--font-title);
  font-size: 1.25rem;
  font-weight: 700;
  text-decoration: none;
  letter-spacing: 2px;
}

.navbar__brand:hover {
  color: var(--color-gold-light);
}

.navbar__brand-icon {
  font-size: 1.5rem;
}

.navbar__menu {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  list-style: none;
  margin: 0;
  padding: 0;
}

.navbar__menu-item {
  position: relative;
}

.navbar__menu-link {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 20px;
  color: var(--color-paper-dark);
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.navbar__menu-link:hover,
.navbar__menu-link--active {
  background: rgba(183, 28, 28, 0.3);
  color: var(--color-gold);
}

.navbar__menu-link--active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 3px;
  background: var(--color-gold);
  border-radius: 2px;
}

/* 移动端汉堡按钮 */
.navbar__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  gap: 5px;
  padding: 0;
}

.navbar__toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-gold);
  transition: all var(--transition-normal);
  border-radius: 1px;
}

.navbar__toggle--active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.navbar__toggle--active span:nth-child(2) {
  opacity: 0;
}

.navbar__toggle--active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* 移动端侧滑菜单 */
.navbar__overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
}

.navbar__overlay--active {
  display: block;
}

@media (max-width: 768px) {
  .navbar__toggle {
    display: flex;
  }

  .navbar__menu {
    position: fixed;
    top: 0;
    right: -280px;
    width: 280px;
    height: 100%;
    flex-direction: column;
    align-items: stretch;
    background: var(--color-ink);
    padding: var(--space-xl) var(--space-lg);
    transition: right var(--transition-normal);
    z-index: 1001;
    gap: var(--space-sm);
    overflow-y: auto;
  }

  .navbar__menu--open {
    right: 0;
  }

  .navbar__menu-link {
    padding: 14px 16px;
    font-size: 1rem;
    border-radius: var(--radius-sm);
  }

  .navbar__menu-link--active::after {
    display: none;
  }
}

/* ===== 面包屑 ===== */
.breadcrumb {
  padding: var(--space-md) 0;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.breadcrumb__list {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: var(--space-xs);
}

.breadcrumb__item {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.breadcrumb__item::after {
  content: '›';
  color: var(--color-text-muted);
  font-size: 1.1em;
}

.breadcrumb__item:last-child::after {
  display: none;
}

.breadcrumb__link {
  color: var(--color-text-light);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.breadcrumb__link:hover {
  color: var(--color-primary);
}

.breadcrumb__current {
  color: var(--color-primary);
  font-weight: 600;
}

/* ===== 页脚 ===== */
.footer {
  background: linear-gradient(135deg, var(--color-ink), #3a3a3a);
  border-top: 3px solid var(--color-primary);
  color: var(--color-paper-dark);
  padding: var(--space-2xl) 0 var(--space-lg);
  margin-top: var(--space-3xl);
}

.footer__inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  text-align: center;
}

.footer__brand {
  font-family: var(--font-title);
  font-size: 1.3rem;
  color: var(--color-gold);
  letter-spacing: 3px;
  margin-bottom: var(--space-md);
}

.footer__brand span {
  color: var(--color-primary-light);
}

.footer__desc {
  font-size: 0.85rem;
  color: #999;
  margin-bottom: var(--space-lg);
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

.footer__divider {
  border: none;
  height: 1px;
  background: linear-gradient(to right, transparent, var(--color-gold-dark), transparent);
  margin: var(--space-lg) 0;
}

.footer__copyright {
  font-size: 0.8rem;
  color: #777;
}

.footer__copyright a {
  color: var(--color-gold);
}

/* ===== 返回顶部 ===== */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 44px;
  height: 44px;
  background: var(--color-primary);
  color: var(--color-white);
  border: 2px solid var(--color-gold);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.2rem;
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-normal);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  z-index: 900;
}

.back-to-top--visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--color-primary-dark);
  transform: translateY(-3px);
  box-shadow: var(--shadow-xl);
}

/* ===== 加载动画 ===== */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--color-paper);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  transition: opacity 0.5s ease;
}

.loading-overlay--hidden {
  opacity: 0;
  pointer-events: none;
}

.loading-spinner {
  text-align: center;
}

.loading-spinner__icon {
  width: 50px;
  height: 50px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto var(--space-md);
}

.loading-spinner__text {
  font-family: var(--font-title);
  color: var(--color-text-light);
  font-size: 0.9rem;
  letter-spacing: 2px;
}

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

/* ===== 模态框/弹窗 ===== */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.modal--active {
  opacity: 1;
  visibility: visible;
}

.modal__backdrop {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
}

.modal__content {
  position: relative;
  background: var(--color-white);
  border: 2px solid var(--color-gold);
  border-radius: var(--radius-lg);
  max-width: 600px;
  width: 90%;
  max-height: 85vh;
  overflow-y: auto;
  padding: var(--space-xl);
  box-shadow: var(--shadow-xl);
  transform: scale(0.9);
  transition: transform var(--transition-normal);
}

.modal--active .modal__content {
  transform: scale(1);
}

.modal__close {
  position: absolute;
  top: var(--space-md);
  right: var(--space-md);
  width: 36px;
  height: 36px;
  border: 1px solid var(--color-border);
  border-radius: 50%;
  background: var(--color-paper-dark);
  color: var(--color-text-light);
  font-size: 1.2rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.modal__close:hover {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}

.modal__title {
  font-family: var(--font-title);
  font-size: 1.3rem;
  color: var(--color-ink);
  margin-bottom: var(--space-lg);
  padding-right: var(--space-xl);
}

.modal__body {
  font-size: 0.95rem;
  line-height: 1.8;
}

/* ===== 页面标题区 ===== */
.page-hero {
  text-align: center;
  padding: var(--space-2xl) 0 var(--space-xl);
  border-bottom: 2px solid var(--color-gold-light);
  margin-bottom: var(--space-xl);
  background: linear-gradient(135deg, rgba(183,28,28,0.03), transparent, rgba(201,169,110,0.05));
}

.page-hero__title {
  font-family: var(--font-title);
  font-size: 2rem;
  color: var(--color-ink);
  margin-bottom: var(--space-sm);
}

.page-hero__subtitle {
  font-size: 1rem;
  color: var(--color-text-light);
  max-width: 600px;
  margin: 0 auto;
}

@media (max-width: 768px) {
  .page-hero__title { font-size: 1.5rem; }
  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 38px;
    height: 38px;
  }
  .modal__content {
    width: 95%;
    padding: var(--space-lg);
  }
}

/* ===== 知识页面侧边导航 ===== */
.knowledge-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: var(--space-xl);
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.knowledge-sidebar {
  position: sticky;
  top: 80px;
  align-self: start;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
}

.knowledge-sidebar__title {
  font-family: var(--font-title);
  font-size: 1rem;
  color: var(--color-ink);
  padding-bottom: var(--space-sm);
  border-bottom: 2px solid var(--color-gold);
  margin-bottom: var(--space-sm);
}

.knowledge-sidebar__list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.knowledge-sidebar__item {
  margin-bottom: 2px;
}

.knowledge-sidebar__link {
  display: block;
  padding: 8px 12px;
  font-size: 0.85rem;
  color: var(--color-text-light);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  line-height: 1.4;
}

.knowledge-sidebar__link:hover {
  background: var(--color-paper-dark);
  color: var(--color-primary);
}

.knowledge-sidebar__link--active {
  background: rgba(183, 28, 28, 0.08);
  color: var(--color-primary);
  font-weight: 600;
  border-left: 3px solid var(--color-primary);
}

.knowledge-content {
  min-width: 0;
}

@media (max-width: 1024px) {
  .knowledge-layout {
    grid-template-columns: 200px 1fr;
    gap: var(--space-lg);
  }
}

@media (max-width: 768px) {
  .knowledge-layout {
    grid-template-columns: 1fr;
  }
  .knowledge-sidebar {
    position: static;
    max-height: none;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: var(--space-md);
    margin-bottom: var(--space-lg);
  }
  .knowledge-sidebar__list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
  }
  .knowledge-sidebar__link {
    padding: 6px 10px;
    font-size: 0.8rem;
  }
}