.page-faq {
  --faq-radius: 26px;
  --faq-body: #4A423C;
  --faq-muted: #6B6058;
  --faq-link: #0E5F52;

  background:
    radial-gradient(1100px 520px at 84% -14%, rgba(53, 240, 208, .13), transparent 62%),
    radial-gradient(900px 480px at 2% 6%, rgba(138, 108, 255, .11), transparent 60%),
    var(--ink-blue-base);
  color: var(--pure-white);
  padding-bottom: 92px;
}

.page-faq .crumbs {
  padding-top: 26px;
}

/* ---------- 首屏 ---------- */
.page-faq .faq-hero {
  padding-top: 26px;
}

.page-faq .faq-hero__label {
  color: var(--fluoro-cyan);
}

.page-faq .faq-hero__title {
  margin: 16px 0 0;
  max-width: 18ch;
  font-size: clamp(30px, 5.4vw, 54px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -.015em;
}

.page-faq .faq-hero__lede {
  margin: 18px 0 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.78;
  color: #C7D3E8;
}

.page-faq .faq-hero__figure {
  margin: 34px 0 0;
}

/* ---------- 数据概览条 ---------- */
.page-faq .faq-metrics {
  margin-top: 46px;
  padding: 26px 22px;
  border: 1px solid var(--line-dark);
  border-radius: var(--faq-radius);
  background: linear-gradient(180deg, rgba(18, 30, 54, .94), rgba(11, 18, 32, .94));
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px 18px;
}

.page-faq .faq-metric__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(30px, 3.6vw, 42px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--fluoro-cyan);
}

.page-faq .faq-metric__num em {
  font-style: normal;
  font-size: .42em;
  font-weight: 700;
  margin-left: 5px;
  letter-spacing: 0;
  color: var(--steel-text);
}

.page-faq .faq-metric__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.62;
  color: var(--steel-text);
}

/* ---------- 主体布局 ---------- */
.page-faq .faq-layout {
  margin-top: 56px;
}

/* ---------- 目录 ---------- */
.page-faq .faq-toc {
  margin-bottom: 38px;
}

.page-faq .faq-toc__label {
  display: none;
  letter-spacing: .14em;
  color: var(--steel-text);
}

.page-faq .faq-toc__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-faq .faq-toc__list::-webkit-scrollbar {
  display: none;
}

.page-faq .faq-toc__list li {
  flex: 0 0 auto;
}

.page-faq .faq-toc__list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 16px;
  border: 1px solid var(--line-dark);
  border-radius: var(--radius-pill);
  color: var(--steel-text);
  font-size: 14px;
  text-decoration: none;
  white-space: nowrap;
  transition: color .18s ease, border-color .18s ease, background .18s ease;
}

.page-faq .faq-toc__num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--fluoro-cyan);
}

.page-faq .faq-toc__list a:hover,
.page-faq .faq-toc__list a:focus-visible {
  color: var(--pure-white);
  border-color: rgba(138, 108, 255, .55);
  background: rgba(53, 240, 208, .08);
}

/* ---------- 章节 ---------- */
.page-faq .faq-topic {
  scroll-margin-top: calc(var(--topline-h) + 26px);
}

.page-faq .faq-topic + .faq-topic {
  margin-top: 62px;
}

.page-faq .faq-topic__head {
  display: grid;
  gap: 10px;
  margin-bottom: 24px;
}

.page-faq .faq-topic__no {
  font-family: var(--font-mono);
  font-size: clamp(34px, 4.6vw, 50px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--fluoro-cyan);
}

.page-faq .faq-topic__head h2 {
  margin: 0;
  font-size: clamp(22px, 3.2vw, 32px);
  font-weight: 800;
  line-height: 1.25;
}

.page-faq .faq-topic__intro {
  margin: 0;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.76;
  color: var(--steel-text);
}

.page-faq .faq-topic__figure {
  margin: 0 0 22px;
}

/* ---------- 排序示意图 ---------- */
.page-faq .faq-diagram {
  margin: 0 0 22px;
  padding: 24px 22px 18px;
  border-radius: var(--faq-radius);
  background: var(--cream-paper);
  color: var(--deep-brown-black);
}

.page-faq .faq-diagram__scroll {
  overflow-x: auto;
  padding-bottom: 6px;
}

.page-faq .faq-diagram svg {
  display: block;
  width: 100%;
  min-width: 560px;
  height: auto;
}

.page-faq .faq-diagram .node {
  fill: none;
  stroke: var(--deep-brown-black);
  stroke-width: 1.6;
}

.page-faq .faq-diagram .node--final {
  stroke: #C25716;
  stroke-dasharray: 6 5;
}

.page-faq .faq-diagram .link {
  fill: none;
  stroke: var(--electric-violet);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.page-faq .faq-diagram .node-text {
  fill: var(--deep-brown-black);
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .01em;
}

.page-faq .faq-diagram .node-text--final {
  fill: #C25716;
}

.page-faq .faq-diagram figcaption {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--faq-muted);
}

/* ---------- 问答卡片 ---------- */
.page-faq .faq-list {
  display: grid;
  gap: 14px;
}

.page-faq .faq-item {
  background: var(--cream-paper);
  color: var(--deep-brown-black);
  border-radius: var(--faq-radius);
  box-shadow: 0 12px 26px rgba(3, 8, 18, .36);
  transition: transform .2s ease, box-shadow .2s ease;
}

.page-faq .faq-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 34px rgba(3, 8, 18, .46);
}

.page-faq .faq-item[open] {
  box-shadow: 0 18px 38px rgba(3, 8, 18, .52);
}

.page-faq .faq-item > summary {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  min-height: 44px;
  padding: 20px 22px;
  list-style: none;
  cursor: pointer;
  font-size: 16.5px;
  font-weight: 700;
  line-height: 1.55;
  color: var(--deep-brown-black);
}

.page-faq .faq-item > summary::-webkit-details-marker {
  display: none;
}

.page-faq .faq-item > summary::marker {
  content: "";
}

.page-faq .faq-item > summary::after {
  content: "+";
  flex: 0 0 auto;
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.25;
  color: #C25716;
  transition: transform .2s ease;
}

.page-faq .faq-item[open] > summary::after {
  content: "−";
}

.page-faq .faq-item[open] > summary {
  border-bottom: 1px solid var(--warm-paper-line);
}

.page-faq .faq-item > summary:focus-visible {
  outline: 2px solid var(--electric-violet);
  outline-offset: -4px;
  border-radius: var(--faq-radius);
}

.page-faq .faq-item > p {
  margin: 0;
  padding: 18px 22px 22px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--faq-body);
}

.page-faq .faq-item a {
  color: var(--faq-link);
  font-weight: 600;
  text-decoration: underline;
  text-decoration-thickness: 1.5px;
  text-underline-offset: 3px;
}

.page-faq .faq-item a:hover {
  text-decoration-color: #C25716;
}

/* ---------- 结尾协助区 ---------- */
.page-faq .faq-help {
  margin-top: 74px;
  padding: 34px 26px;
  border: 1px solid rgba(53, 240, 208, .26);
  border-radius: var(--faq-radius);
  background:
    linear-gradient(135deg, rgba(53, 240, 208, .12), rgba(138, 108, 255, .12) 58%, rgba(11, 18, 32, .94)),
    var(--midnight-panel);
  display: grid;
  gap: 14px;
}

.page-faq .faq-help h2 {
  margin: 0;
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 800;
  line-height: 1.28;
}

.page-faq .faq-help p {
  margin: 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.76;
  color: #C7D3E8;
}

.page-faq .faq-help__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 6px;
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 640px) {
  .page-faq .faq-topic__head {
    grid-template-columns: auto minmax(0, 1fr);
    column-gap: 20px;
    row-gap: 10px;
    align-items: start;
  }

  .page-faq .faq-topic__no {
    grid-row: 1 / span 2;
  }

  .page-faq .faq-topic__head h2 {
    grid-column: 2;
  }

  .page-faq .faq-topic__intro {
    grid-column: 2;
  }

  .page-faq .faq-help {
    padding: 40px 38px;
  }
}

@media (min-width: 900px) {
  .page-faq .faq-metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    padding: 30px 32px;
  }
}

/* ---------- 桌面：侧栏目录常驻 ---------- */
@media (min-width: 1024px) {
  .page-faq .faq-layout {
    display: grid;
    grid-template-columns: 252px minmax(0, 1fr);
    gap: 54px;
    align-items: start;
  }

  .page-faq .faq-toc {
    position: sticky;
    top: calc(var(--topline-h) + 30px);
    margin-bottom: 0;
  }

  .page-faq .faq-toc__label {
    display: block;
  }

  .page-faq .faq-toc__list {
    flex-direction: column;
    gap: 2px;
    margin-top: 14px;
    padding: 0;
    overflow: visible;
    border-left: 1px solid var(--line-dark);
  }

  .page-faq .faq-toc__list a {
    justify-content: flex-start;
    width: 100%;
    min-height: 40px;
    padding: 0 14px;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0 12px 12px 0;
    white-space: normal;
  }

  .page-faq .faq-toc__list a:hover,
  .page-faq .faq-toc__list a:focus-visible {
    border-left-color: var(--electric-violet);
    background: rgba(53, 240, 208, .08);
  }

  .page-faq .faq-content {
    min-width: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-faq .faq-item,
  .page-faq .faq-item > summary::after,
  .page-faq .faq-toc__list a {
    transition: none;
  }

  .page-faq .faq-item:hover {
    transform: none;
  }
}