/* ========== 帮助中心页面专属样式 ========== */
.page-faq {
  --faq-bg: var(--bg-dark);
  --faq-text: var(--text-primary);
  --faq-nav-width: 260px;
  --faq-gap: 40px;
  --faq-border: var(--border-strong);
  --faq-icon-size: 24px;
  --faq-answer-bg: var(--surface-mid);
  --faq-answer-text: #1a1a1a;
  background: var(--faq-bg);
  color: var(--faq-text);
  padding: 2rem 1rem;
  min-height: 80vh;
}

/* 面包屑 */
.page-faq .breadcrumb {
  max-width: var(--container-max);
  margin: 0 auto 1.5rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: var(--text-secondary);
}
.page-faq .breadcrumb a {
  color: var(--secondary);
  text-decoration: none;
}
.page-faq .breadcrumb a:hover {
  color: var(--primary);
}
.page-faq .breadcrumb .sep {
  margin: 0 0.5rem;
  color: var(--metal-silver);
}
.page-faq .breadcrumb .current-page {
  color: var(--text-primary);
}

/* 布局：左导航 + 右内容 */
.page-faq .faq-layout {
  max-width: var(--container-max);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}
@media (min-width: 768px) {
  .page-faq .faq-layout {
    flex-direction: row;
    gap: var(--faq-gap);
  }
}

/* 左侧导航 */
.page-faq .faq-nav {
  flex: 0 0 var(--faq-nav-width);
  position: sticky;
  top: calc(var(--header-height) + 1rem);
  align-self: flex-start;
  max-height: calc(100vh - var(--header-height) - 2rem);
  overflow-y: auto;
  border-right: 2px solid var(--faq-border);
  padding-right: 1rem;
}
@media (max-width: 767px) {
  .page-faq .faq-nav {
    position: static;
    border-right: none;
    border-bottom: 2px solid var(--faq-border);
    padding-right: 0;
    padding-bottom: 1rem;
    max-height: none;
  }
}
.page-faq .faq-nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-faq .nav-cat-link {
  display: block;
  padding: 0.75rem 0.5rem;
  font-family: var(--font-headline);
  font-size: 1rem;
  color: var(--text-secondary);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: all 0.2s ease;
}
.page-faq .nav-cat-link:hover,
.page-faq .nav-cat-link:focus-visible {
  color: var(--primary);
  border-left-color: var(--primary);
  background: rgba(255,45,45,0.05);
}
@media (prefers-reduced-motion: reduce) {
  .page-faq .nav-cat-link {
    transition: none;
  }
}

/* 右侧内容 */
.page-faq .faq-content {
  flex: 1;
  min-width: 0;
}

/* 页面标题 */
.page-faq .faq-page-title {
  font-family: var(--font-headline);
  font-size: 2.5rem;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin: 0 0 0.5rem;
  color: var(--text-primary);
}
.page-faq .faq-page-desc {
  font-family: var(--font-body);
  color: var(--text-secondary);
  margin-bottom: 2.5rem;
  font-size: 1rem;
  line-height: 1.6;
}

/* 分类区块 */
.page-faq .faq-category {
  margin-bottom: 3rem;
  scroll-margin-top: calc(var(--header-height) + 1rem);
}
.page-faq .category-title {
  font-family: var(--font-headline);
  font-size: 1.75rem;
  line-height: 1.2;
  color: var(--text-primary);
  margin: 0 0 1.25rem;
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
}
.page-faq .cat-number {
  font-family: var(--font-headline);
  font-size: 2rem;
  color: var(--primary);
  opacity: 0.8;
}

/* 手风琴项目 */
.page-faq .faq-item {
  border-bottom: 1px solid var(--faq-border);
  margin-bottom: 0.25rem;
}
/* 隐藏checkbox */
.page-faq .faq-toggle {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}
/* 问题标签 */
.page-faq .faq-question {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 0.5rem;
  cursor: pointer;
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  user-select: none;
  transition: background 0.2s;
}
.page-faq .faq-question:hover {
  background: rgba(255,45,45,0.08);
}
.page-faq .faq-number {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: var(--primary);
  color: #fff;
  font-family: var(--font-headline);
  font-size: 0.85rem;
  border-radius: 50%;
  font-weight: bold;
}
.page-faq .faq-title {
  flex: 1;
}
.page-faq .faq-icon {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: var(--faq-icon-size);
  height: var(--faq-icon-size);
  color: var(--primary);
  font-size: 1.5rem;
  font-weight: bold;
  line-height: 1;
  transition: transform 0.3s ease;
}
/* checkbox选中时图标旋转45度（+变×） */
.page-faq .faq-toggle:checked + .faq-question .faq-icon {
  transform: rotate(45deg);
}
@media (prefers-reduced-motion: reduce) {
  .page-faq .faq-icon {
    transition: none;
  }
  .page-faq .faq-question {
    transition: none;
  }
}

/* 答案区域 */
.page-faq .faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  background: var(--faq-answer-bg);
  color: var(--faq-answer-text);
  padding: 0 0.5rem;
  border-radius: 0 0 6px 6px;
}
.page-faq .faq-answer p {
  margin: 0 0 0.75rem;
  line-height: 1.6;
  font-size: 0.95rem;
}
.page-faq .faq-answer a {
  color: var(--secondary);
  text-decoration: underline;
  text-underline-offset: 2px;
}
.page-faq .faq-answer a:hover {
  color: var(--primary);
}
/* 展开状态 */
.page-faq .faq-toggle:checked ~ .faq-answer {
  max-height: 500px;
  padding: 1rem 0.5rem 1.25rem;
}
@media (prefers-reduced-motion: reduce) {
  .page-faq .faq-answer {
    transition: none;
  }
}

/* 图片块 */
.page-faq .faq-image-block {
  margin: 1.5rem 0;
  background: var(--surface-dark);
  border: 2px solid var(--faq-border);
  padding: 1rem;
  border-radius: 8px;
  text-align: center;
}
.page-faq .faq-image {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
  border: 1px solid var(--metal-silver);
  border-radius: 4px;
}
.page-faq .faq-image-caption {
  margin: 0.75rem 0 0;
  font-family: var(--font-body);
  font-size: 0.85rem;
  color: var(--text-secondary);
  letter-spacing: 0.02em;
}

/* 页脚注释 */
.page-faq .faq-footnote {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 2px solid var(--faq-border);
  font-family: var(--font-body);
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}
.page-faq .faq-footnote a {
  color: var(--secondary);
  text-decoration: underline;
}
.page-faq .faq-footnote strong {
  color: var(--text-primary);
}

/* 辅助隐藏 */
.page-faq .visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

/* 响应式微调 */
@media (max-width: 639px) {
  .page-faq {
    padding: 1.5rem 0.75rem;
  }
  .page-faq .faq-page-title {
    font-size: 1.75rem;
  }
  .page-faq .category-title {
    font-size: 1.25rem;
  }
  .page-faq .faq-question {
    font-size: 0.9rem;
    padding: 0.75rem 0.25rem;
  }
  .page-faq .faq-number {
    width: 24px;
    height: 24px;
    font-size: 0.75rem;
  }
}