.page-faq {
  --faq-panel-h: 420px;
  position: relative;
  background:
    radial-gradient(120% 55% at 10% 0%, rgba(53, 242, 216, .07), transparent 60%),
    var(--ink);
  color: var(--paper);
}

/* ---------- 换乘大厅首屏 ---------- */
.page-faq .hub {
  position: relative;
  padding: calc(var(--header-h) + 36px) 0 56px;
}

.page-faq .hub::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--cyan), rgba(53, 242, 216, 0) 62%);
  opacity: .4;
}

.page-faq .hub__top {
  display: grid;
  gap: 28px;
}

.page-faq .hub__intro {
  max-width: 52ch;
}

.page-faq .hub__promise {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-faq .hub__promise li {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  color: var(--grey);
  font-size: 15px;
  line-height: 1.75;
}

.page-faq .hub__promise .mono {
  color: var(--amber);
  font-size: 12px;
}

.page-faq .hub__hint {
  margin: 22px 0 0;
  padding: 12px 16px;
  border-left: 2px solid var(--amber);
  border-radius: 2px 14px 4px 14px;
  background: rgba(255, 138, 61, .09);
  color: var(--grey);
  font-size: 15px;
  line-height: 1.75;
}

.page-faq .hub__figure {
  margin: 0;
  max-width: 340px;
}

.page-faq .hub__figure img {
  display: block;
}

/* 索引地图 */
.page-faq .hub__map {
  margin-top: 40px;
  display: grid;
  gap: 18px;
  padding: 16px;
  border: 1px solid var(--track);
  border-radius: var(--radius-soft);
  background: linear-gradient(180deg, rgba(14, 29, 53, .94), rgba(8, 18, 38, .72));
}

.page-faq .hub__map-label {
  margin: 0 0 12px;
  color: var(--index);
  font-size: 11px;
  letter-spacing: .14em;
}

.page-faq .hub__group-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 4px;
}

.page-faq .hub__group {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr) auto;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 6px 12px;
  border-left: 3px solid var(--cyan);
  border-radius: 2px 14px 4px 14px;
  color: var(--paper);
  font-size: 15px;
  text-decoration: none;
  transition: background .2s var(--ease), transform .2s var(--ease);
}

.page-faq .hub__group:hover,
.page-faq .hub__group:focus-visible {
  background: linear-gradient(90deg, rgba(53, 242, 216, .16), rgba(53, 242, 216, 0));
  transform: translateX(3px);
}

.page-faq .hub__group:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-faq .hub__group .index-num {
  color: var(--cyan);
}

.page-faq .hub__group-count {
  color: var(--index);
  font-size: 11px;
  white-space: nowrap;
}

.page-faq .hub__panel {
  border-radius: var(--radius-chip);
  background: rgba(8, 18, 38, .5);
  padding: 16px 14px;
}

.page-faq .hub__panel:focus-visible {
  outline: 1px solid var(--track);
  outline-offset: 2px;
}

.page-faq .hub__panel-inner {
  display: grid;
  gap: 18px;
}

.page-faq .hub__block {
  padding-left: 14px;
  border-left: 1px solid var(--track);
}

.page-faq .hub__block-title {
  display: flex;
  gap: 10px;
  align-items: baseline;
  margin: 0 0 6px;
  color: var(--paper);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .01em;
}

.page-faq .hub__block-title .index-num {
  color: var(--amber);
  font-weight: 400;
  font-size: 12px;
}

.page-faq .hub__entries {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-faq .hub__entries a {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  min-height: 44px;
  padding: 4px 0;
  color: var(--grey);
  font-size: 15px;
  line-height: 1.6;
  text-decoration: none;
  transition: color .2s var(--ease);
}

.page-faq .hub__entries a::before {
  content: "→";
  color: var(--amber);
  font-size: 13px;
  flex: none;
}

.page-faq .hub__entries a:hover,
.page-faq .hub__entries a:focus-visible {
  color: var(--cyan);
}

.page-faq .hub__panel::-webkit-scrollbar {
  width: 6px;
}

.page-faq .hub__panel::-webkit-scrollbar-thumb {
  background: var(--track);
  border-radius: 99px;
}

/* ---------- 页内目录 ---------- */
.page-faq .page-toc {
  position: sticky;
  top: var(--header-h);
  z-index: 6;
  background: rgba(8, 18, 38, .95);
  border-top: 1px solid var(--track);
  border-bottom: 1px solid var(--track);
  backdrop-filter: blur(10px);
}

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

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

.page-faq .page-toc a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  border: 1px solid transparent;
  border-radius: var(--radius-chip);
  color: var(--grey);
  font-size: 14px;
  text-decoration: none;
  white-space: nowrap;
  transition: color .2s var(--ease), background .2s var(--ease);
}

.page-faq .page-toc a:hover,
.page-faq .page-toc a:focus-visible,
.page-faq .page-toc a[aria-current="true"] {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}

/* ---------- 章节间距 ---------- */
.page-faq .section {
  padding: 60px 0;
}

/* ---------- 文档树 ---------- */
.page-faq .doc-tree {
  display: grid;
  gap: 10px;
  margin-top: 34px;
}

.page-faq .doc-group {
  border: 1px solid var(--track);
  border-radius: var(--radius-soft);
  background: linear-gradient(180deg, rgba(14, 29, 53, .88), rgba(8, 18, 38, .62));
  overflow: hidden;
  transition: border-color .2s var(--ease);
}

.page-faq .doc-group[open] {
  border-color: rgba(53, 242, 216, .45);
}

.page-faq .doc-group summary {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) auto 20px;
  align-items: center;
  gap: 12px;
  min-height: 56px;
  padding: 12px 16px;
  cursor: pointer;
  list-style: none;
  transition: background .2s var(--ease);
}

.page-faq .doc-group summary::-webkit-details-marker {
  display: none;
}

.page-faq .doc-group summary:hover,
.page-faq .doc-group summary:focus-visible {
  background: rgba(30, 58, 92, .45);
}

.page-faq .doc-group summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-faq .doc-group summary .index-num {
  color: var(--cyan);
  font-size: 13px;
}

.page-faq .doc-group__name {
  color: var(--paper);
  font-size: 17px;
  font-weight: 600;
}

.page-faq .doc-group__count {
  color: var(--index);
  font-size: 11px;
  letter-spacing: .08em;
  white-space: nowrap;
}

.page-faq .doc-group__mark {
  position: relative;
  width: 20px;
  height: 20px;
  justify-self: end;
}

.page-faq .doc-group__mark::before,
.page-faq .doc-group__mark::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: var(--cyan);
  transform: translate(-50%, -50%);
  transition: transform .2s var(--ease), opacity .2s var(--ease);
}

.page-faq .doc-group__mark::before {
  width: 12px;
  height: 1px;
}

.page-faq .doc-group__mark::after {
  width: 1px;
  height: 12px;
}

.page-faq .doc-group[open] .doc-group__mark::after {
  transform: translate(-50%, -50%) scaleY(0);
  opacity: 0;
}

.page-faq .doc-list {
  list-style: none;
  margin: 0 16px 18px 62px;
  padding: 2px 0 2px 16px;
  border-left: 1px solid var(--track);
  display: grid;
  gap: 2px;
}

.page-faq .doc-list li {
  position: relative;
  padding: 8px 0;
  color: var(--grey);
  font-size: 15px;
  line-height: 1.7;
  transition: color .2s var(--ease);
}

.page-faq .doc-list li::before {
  content: "";
  position: absolute;
  left: -16px;
  top: 50%;
  width: 12px;
  height: 1px;
  background: var(--track);
}

.page-faq .doc-list li:hover {
  color: var(--paper);
}

/* ---------- 常见说明 ---------- */
.page-faq .brief {
  display: grid;
  gap: 28px;
  margin-top: 32px;
}

.page-faq .brief__cats {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-faq .brief__cats li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 13px 15px;
  border-radius: var(--radius-chip);
  background: rgba(30, 58, 92, .34);
  color: var(--grey);
  font-size: 15px;
  line-height: 1.75;
}

.page-faq .brief__cats .tag {
  margin-top: 2px;
}

.page-faq .brief__figure {
  margin: 0;
}

/* ---------- 术语对照 ---------- */
.page-faq .term-list {
  display: grid;
  gap: 10px;
  margin: 32px 0 0;
}

.page-faq .term {
  display: grid;
  gap: 6px;
  padding: 14px 16px;
  border-left: 2px solid var(--track);
  border-radius: 2px 14px 4px 14px;
  background: rgba(14, 29, 53, .62);
  transition: border-color .2s var(--ease);
}

.page-faq .term:hover {
  border-left-color: var(--cyan);
}

.page-faq .term dt {
  color: var(--paper);
  font-size: 16px;
  font-weight: 600;
}

.page-faq .term dd {
  margin: 0;
  color: var(--grey);
  font-size: 15px;
  line-height: 1.7;
}

.page-faq .term dd::before {
  content: "也叫 ";
  color: var(--index);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
}

/* ---------- 联系与反馈 ---------- */
.page-faq .support-card {
  display: grid;
  gap: 26px;
  padding: 22px;
  border: 1px solid var(--track);
  border-radius: var(--radius-soft);
  background:
    radial-gradient(90% 120% at 100% 0%, rgba(255, 138, 61, .14), transparent 58%),
    linear-gradient(180deg, rgba(14, 29, 53, .96), rgba(8, 18, 38, .86));
}

.page-faq .support-card__contact {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-faq .support-card__contact li {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(23, 48, 79, .75);
  color: var(--paper);
  font-size: 15px;
  line-height: 1.7;
  word-break: break-word;
}

.page-faq .support-card__contact li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-faq .support-card__contact .mono {
  color: var(--index);
  font-size: 11px;
  letter-spacing: .1em;
}

.page-faq .support-card__aside-title {
  margin: 0 0 12px;
  color: var(--index);
  font-size: 11px;
  letter-spacing: .14em;
}

.page-faq .support-card__aside ul {
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-faq .support-card__aside a:not(.btn) {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  color: var(--grey);
  font-size: 15px;
  text-decoration: none;
  transition: color .2s var(--ease);
}

.page-faq .support-card__aside a:not(.btn)::before {
  content: "→";
  color: var(--amber);
  font-size: 13px;
}

.page-faq .support-card__aside a:not(.btn):hover,
.page-faq .support-card__aside a:not(.btn):focus-visible {
  color: var(--cyan);
}

/* ---------- 返回顶部 ---------- */
.page-faq .to-top {
  position: fixed;
  right: 18px;
  bottom: calc(var(--dock-h) + 18px);
  z-index: 20;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  padding: 0;
  border: 1px solid var(--track);
  border-radius: 50%;
  background: rgba(14, 29, 53, .95);
  color: var(--cyan);
  font-size: 16px;
  line-height: 1;
  cursor: pointer;
  transition: border-color .2s var(--ease), transform .2s var(--ease);
}

.page-faq .to-top:hover,
.page-faq .to-top:focus-visible {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

/* ---------- 窄屏 ---------- */
@media (max-width: 599px) {
  .page-faq .hub {
    padding-top: calc(var(--header-h) + 24px);
  }

  .page-faq .hub__figure {
    max-width: none;
  }

  .page-faq .hub__map {
    padding: 12px;
  }

  .page-faq .hub__panel {
    padding: 14px 10px;
  }

  .page-faq .doc-group summary {
    grid-template-columns: 26px minmax(0, 1fr) auto 20px;
    gap: 8px;
    padding: 12px;
  }

  .page-faq .doc-group__name {
    font-size: 16px;
  }

  .page-faq .doc-list {
    margin-left: 30px;
    margin-right: 12px;
    padding-left: 14px;
  }

  .page-faq .doc-list li::before {
    left: -14px;
    width: 10px;
  }

  .page-faq .support-card {
    padding: 18px 16px;
  }

  .page-faq .support-card__contact li {
    grid-template-columns: minmax(0, 1fr);
    gap: 4px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-faq .hub {
    padding-top: calc(var(--header-h) + 56px);
    padding-bottom: 72px;
  }

  .page-faq .hub__top {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    align-items: start;
    gap: 56px;
  }

  .page-faq .hub__figure {
    max-width: none;
  }

  .page-faq .hub__map {
    margin-top: 52px;
    grid-template-columns: minmax(220px, 272px) minmax(0, 1fr);
    gap: 26px;
    padding: 22px;
  }

  .page-faq .hub__groups {
    position: sticky;
    top: calc(var(--header-h) + 24px);
  }

  .page-faq .hub__panel {
    max-height: var(--faq-panel-h);
    overflow-y: auto;
    padding: 18px 16px;
  }

  .page-faq .section {
    padding: 88px 0;
  }

  .page-faq .doc-tree {
    grid-template-columns: minmax(0, 1fr);
    gap: 12px;
  }

  .page-faq .brief {
    grid-template-columns: minmax(0, 1fr) minmax(0, .82fr);
    align-items: start;
    gap: 44px;
  }

  .page-faq .term-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
  }

  .page-faq .support-card {
    grid-template-columns: minmax(0, 1.4fr) minmax(220px, .6fr);
    gap: 44px;
    padding: 36px 40px;
  }

  .page-faq .support-card__aside {
    border-left: 1px solid var(--track);
    padding-left: 32px;
  }
}

@media (min-width: 1200px) {
  .page-faq .term-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 24px;
  }
}

/* ---------- 底部栏留白 ---------- */
@media (max-width: 960px) {
  .page-faq {
    padding-bottom: calc(var(--dock-h) + 32px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-faq .hub__group,
  .page-faq .hub__entries a,
  .page-faq .doc-group summary,
  .page-faq .to-top,
  .page-faq .term {
    transition: none;
  }
}