.page-faq {
  --faq-rail-w: 232px;
  --faq-sticky-top: 100px;
  --faq-num-col: 3.6rem;
  background-color: var(--c-paper);
  color: var(--text-on-light);
}

/* ===== 面包屑 ===== */
.page-faq .faq-crumb {
  background-color: var(--c-ink);
  border-bottom: 1px solid var(--line-on-dark);
}

.page-faq .faq-crumb .wrap {
  padding-block: 0.85rem;
}

.page-faq .faq-crumb .breadcrumb a {
  color: var(--text-on-dark-soft);
  text-decoration: none;
  transition: color var(--t-fast) var(--ease);
}

.page-faq .faq-crumb .breadcrumb a:hover,
.page-faq .faq-crumb .breadcrumb a:focus-visible {
  color: var(--c-brass-lit);
}

.page-faq .faq-crumb .breadcrumb [aria-current="page"] {
  color: var(--c-brass-lit);
}

/* ===== 首屏 ===== */
.page-faq .faq-hero {
  position: relative;
  background-color: var(--c-ink);
  background-image:
    linear-gradient(rgba(110, 122, 133, 0.13) 1px, transparent 1px),
    linear-gradient(90deg, rgba(110, 122, 133, 0.13) 1px, transparent 1px);
  background-size: 76px 76px;
  background-position: -1px -1px;
  color: var(--text-on-dark);
  padding-block: clamp(2.5rem, 7vw, 5rem) clamp(2.25rem, 5vw, 3.75rem);
}

.page-faq .faq-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--c-brass) 0%, var(--c-brass) 22%, transparent 22%, transparent 100%);
}

.page-faq .faq-hero__grid {
  display: grid;
  gap: clamp(1.75rem, 4vw, 3rem);
}

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

.page-faq .faq-hero h1 {
  margin: 0.85rem 0 0;
  font-size: clamp(1.9rem, 5.2vw, 3.05rem);
  line-height: 1.2;
  letter-spacing: -0.01em;
  font-weight: 800;
  max-width: 17em;
}

.page-faq .faq-hero__lede {
  margin: 1.15rem 0 0;
  max-width: 34em;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--text-on-dark-soft);
}

.page-faq .faq-hero__facts {
  list-style: none;
  margin: 1.9rem 0 0;
  padding: 1.35rem 0 0;
  border-top: 1px solid var(--line-on-dark);
  display: grid;
  gap: 0.9rem;
}

.page-faq .faq-hero__facts li {
  display: grid;
  grid-template-columns: 3.4rem minmax(0, 1fr);
  gap: 0.9rem;
  align-items: baseline;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--text-on-dark-soft);
}

.page-faq .faq-hero__num {
  font-size: 1.4rem;
  line-height: 1;
  color: var(--c-brass-lit);
  padding-left: 0.6rem;
  border-left: 2px solid var(--c-brass);
  letter-spacing: 0.02em;
}

.page-faq .faq-hero__aside {
  background-color: rgba(22, 40, 60, 0.62);
  border: 1px solid var(--line-on-dark);
  border-top: 2px solid var(--c-brass);
  padding: 1.5rem 1.45rem 1.45rem;
}

.page-faq .faq-hero__note {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--text-on-dark-soft);
}

.page-faq .faq-hero__links {
  margin-top: 1.35rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

/* ===== 分类索引 ===== */
.page-faq .faq-index {
  background-color: var(--c-ink);
  color: var(--text-on-dark);
  padding-block: clamp(2.5rem, 6vw, 4.25rem);
  border-bottom: 1px solid var(--line-on-dark);
}

.page-faq .faq-index__head {
  max-width: 42rem;
  margin-bottom: clamp(1.5rem, 3vw, 2.25rem);
}

.page-faq .faq-index__head h2 {
  margin: 0.7rem 0 0;
  font-size: clamp(1.4rem, 3.2vw, 2rem);
  line-height: 1.3;
  font-weight: 800;
  letter-spacing: -0.005em;
}

.page-faq .faq-index__lede {
  margin: 0.85rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--text-on-dark-soft);
}

.page-faq .faq-index__figure {
  margin: 0 0 clamp(1.5rem, 3vw, 2.25rem);
  position: relative;
  border: 1px solid var(--line-on-dark);
  border-left: 3px solid var(--c-brass);
  overflow: hidden;
}

.page-faq .faq-index__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 1400 / 900;
  object-fit: cover;
  filter: saturate(0.72) contrast(1.04);
}

.page-faq .faq-index__figure .media-frame__caption {
  display: block;
  padding: 0.72rem 1rem;
  background-color: var(--c-ink-2);
  border-top: 1px solid var(--line-on-dark);
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--text-on-dark-soft);
}

.page-faq .faq-index__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background-color: var(--line-on-dark);
  border: 1px solid var(--line-on-dark);
}

.page-faq .faq-card {
  display: block;
  padding: 1.45rem 1.35rem 1.4rem;
  background-color: var(--c-ink);
  color: var(--text-on-dark);
  text-decoration: none;
  transition: background-color var(--t-base) var(--ease);
}

.page-faq .faq-card:hover,
.page-faq .faq-card:focus-visible {
  background-color: var(--c-ink-3);
}

.page-faq .faq-card:focus-visible {
  outline: 2px solid var(--c-brass-lit);
  outline-offset: -2px;
}

.page-faq .faq-card__num {
  display: block;
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  color: var(--c-brass);
}

.page-faq .faq-card__title {
  margin: 0.65rem 0 0.5rem;
  font-size: 1.125rem;
  font-weight: 700;
  line-height: 1.4;
}

.page-faq .faq-card__desc {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--text-on-dark-soft);
}

.page-faq .faq-card__count {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 1.1rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--line-on-dark);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--c-brass-lit);
  transition: color var(--t-fast) var(--ease);
}

.page-faq .faq-card:hover .faq-card__count {
  color: var(--c-paper-warm);
}

/* ===== 搜索与筛选条 ===== */
.page-faq .faq-toolbar {
  position: relative;
  overflow: hidden;
  background-color: var(--c-ink-2);
  border-bottom: 1px solid var(--line-on-dark);
}

.page-faq .faq-toolbar__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  max-width: none;
  object-fit: cover;
  opacity: 0.16;
  pointer-events: none;
  filter: saturate(0.5);
}

.page-faq .faq-toolbar__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 1.1rem;
  padding-block: clamp(1.25rem, 3vw, 1.75rem);
}

.page-faq .faq-search {
  display: grid;
  gap: 0.5rem;
  min-width: 0;
}

.page-faq .faq-search__label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-brass);
}

.page-faq .faq-search__field {
  position: relative;
  display: flex;
  align-items: center;
  border: 1px solid var(--line-on-dark-strong);
  background-color: rgba(14, 27, 42, 0.72);
  transition: border-color var(--t-base) var(--ease), box-shadow var(--t-base) var(--ease);
}

.page-faq .faq-search__field:focus-within {
  border-color: var(--c-brass-lit);
  box-shadow: 0 0 0 1px var(--c-brass-lit);
}

.page-faq .faq-search__icon {
  flex: none;
  width: 15px;
  height: 15px;
  margin-inline: 0.9rem 0;
  color: var(--c-feather);
}

.page-faq .faq-search__field:focus-within .faq-search__icon {
  color: var(--c-brass-lit);
}

.page-faq .faq-search input {
  flex: 1 1 auto;
  min-width: 0;
  border: 0;
  background: transparent;
  padding: 0.85rem 0.9rem 0.85rem 0.7rem;
  font-family: inherit;
  font-size: 0.9375rem;
  color: var(--text-on-dark);
  outline: none;
}

.page-faq .faq-search input::placeholder {
  color: rgba(232, 235, 238, 0.46);
}

.page-faq .faq-search input::-webkit-search-cancel-button {
  filter: invert(0.7);
}

.page-faq .faq-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.page-faq .faq-filters a {
  display: inline-block;
  padding: 0.46rem 0.85rem;
  border: 1px solid var(--line-on-dark-strong);
  font-size: 0.8125rem;
  line-height: 1.4;
  color: var(--text-on-dark-soft);
  text-decoration: none;
  transition: border-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease), background-color var(--t-fast) var(--ease);
}

.page-faq .faq-filters a:hover,
.page-faq .faq-filters a:focus-visible {
  border-color: var(--c-brass-lit);
  color: var(--c-brass-lit);
  background-color: rgba(216, 174, 99, 0.08);
}

/* ===== 问答主体 ===== */
.page-faq .faq-body {
  background-color: var(--c-paper);
  padding-block: clamp(2.5rem, 6vw, 4.25rem);
}

.page-faq .faq-body__grid {
  display: grid;
  gap: clamp(1.75rem, 4vw, 2.5rem);
}

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

.page-faq .faq-rail__inner {
  background-color: var(--c-paper-warm);
  border-left: 3px solid var(--c-brass);
  padding: 1.2rem 1.2rem 1.3rem;
}

.page-faq .faq-rail__title {
  margin: 0 0 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.2em;
  color: var(--c-brass);
}

.page-faq .faq-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-faq .faq-rail__list a {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.68rem 0;
  border-bottom: 1px solid var(--line);
  font-size: 0.9375rem;
  line-height: 1.5;
  color: var(--text-on-light);
  text-decoration: none;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}

.page-faq .faq-rail__list a:hover,
.page-faq .faq-rail__list a:focus-visible {
  color: var(--c-brass);
  border-bottom-color: var(--c-brass);
}

.page-faq .faq-rail__list .mono {
  flex: none;
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  color: var(--c-feather);
}

.page-faq .faq-rail__note {
  margin-top: 1.15rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

.page-faq .faq-rail__note p {
  margin: 0 0 0.6rem;
  font-size: 0.8125rem;
  line-height: 1.75;
  color: var(--text-on-light-soft);
}

.page-faq .faq-rail__note a {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--c-brass);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

.page-faq .faq-rail__note a:hover,
.page-faq .faq-rail__note a:focus-visible {
  color: var(--c-clay);
}

/* 分组 */
.page-faq .faq-stream {
  min-width: 0;
}

.page-faq .faq-group {
  scroll-margin-top: 116px;
  margin-bottom: clamp(2.25rem, 5vw, 3.25rem);
}

.page-faq .faq-group:last-child {
  margin-bottom: 0;
}

.page-faq .faq-group__head {
  display: flex;
  align-items: baseline;
  gap: 0.8rem;
  padding-bottom: 0.7rem;
  margin-bottom: 1.1rem;
  border-bottom: 2px solid var(--c-ink);
}

.page-faq .faq-group__num {
  flex: none;
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--c-brass);
}

.page-faq .faq-group__title {
  margin: 0;
  font-size: clamp(1.2rem, 2.6vw, 1.5rem);
  line-height: 1.35;
  font-weight: 800;
}

.page-faq .faq-group__meta {
  display: none;
  margin-left: auto;
  flex: none;
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  color: var(--c-feather);
}

/* 问答条目 */
.page-faq .faq-item {
  border-left: 3px solid transparent;
  border-bottom: 1px solid var(--line);
  transition: border-color var(--t-base) var(--ease), background-color var(--t-base) var(--ease);
}

.page-faq .faq-item[open] {
  border-left-color: var(--c-brass-lit);
  background-color: var(--c-paper-warm);
}

.page-faq .faq-item__q {
  display: flex;
  align-items: baseline;
  gap: 0.85rem;
  padding: 1.05rem 1.05rem 1.05rem 0.95rem;
  cursor: pointer;
  list-style: none;
  font-size: clamp(0.9375rem, 1.7vw, 1.0625rem);
  font-weight: 600;
  line-height: 1.65;
  color: var(--text-on-light);
  transition: color var(--t-fast) var(--ease);
}

.page-faq .faq-item__q::-webkit-details-marker {
  display: none;
}

.page-faq .faq-item__q::marker {
  content: "";
}

.page-faq .faq-item__q:hover {
  color: var(--c-brass);
}

.page-faq .faq-item__q:focus-visible {
  outline: 2px solid var(--c-brass-lit);
  outline-offset: -2px;
}

.page-faq .faq-item__num {
  flex: none;
  min-width: 2.9em;
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--c-feather);
  transition: color var(--t-base) var(--ease);
}

.page-faq .faq-item[open] .faq-item__num {
  color: var(--c-brass);
}

.page-faq .faq-item__text {
  flex: 1 1 auto;
  min-width: 0;
}

.page-faq .faq-item__icon {
  flex: none;
  position: relative;
  align-self: center;
  width: 13px;
  height: 13px;
  margin-left: 0.9rem;
}

.page-faq .faq-item__icon::before,
.page-faq .faq-item__icon::after {
  content: "";
  position: absolute;
  background-color: var(--c-feather);
  transition: transform var(--t-base) var(--ease), background-color var(--t-base) var(--ease);
}

.page-faq .faq-item__icon::before {
  top: 5.5px;
  left: 0;
  width: 13px;
  height: 2px;
}

.page-faq .faq-item__icon::after {
  top: 0;
  left: 5.5px;
  width: 2px;
  height: 13px;
}

.page-faq .faq-item[open] .faq-item__icon::before {
  background-color: var(--c-brass-lit);
}

.page-faq .faq-item[open] .faq-item__icon::after {
  transform: scaleY(0);
}

.page-faq .faq-item__a {
  padding: 0 1.5rem 1.25rem 3.75rem;
}

.page-faq .faq-item__a > p {
  margin: 0;
  max-width: 62ch;
  font-size: 0.9375rem;
  line-height: 1.9;
  color: var(--text-on-light-soft);
}

/* ===== 联系区块 ===== */
.page-faq .faq-contact {
  position: relative;
  background-color: var(--c-ink);
  background-image:
    linear-gradient(rgba(110, 122, 133, 0.1) 1px, transparent 1px),
    linear-gradient(90deg, rgba(110, 122, 133, 0.1) 1px, transparent 1px);
  background-size: 76px 76px;
  color: var(--text-on-dark);
  padding-block: clamp(2.75rem, 6vw, 4.5rem);
  border-top: 3px solid var(--c-brass);
}

.page-faq .faq-contact__grid {
  display: grid;
  gap: clamp(1.75rem, 4vw, 3rem);
}

.page-faq .faq-contact__main h2 {
  margin: 0.75rem 0 0;
  font-size: clamp(1.4rem, 3.4vw, 2.05rem);
  line-height: 1.32;
  font-weight: 800;
  max-width: 16em;
}

.page-faq .faq-contact__lede {
  margin: 1rem 0 0;
  max-width: 32em;
  font-size: 0.9375rem;
  line-height: 1.9;
  color: var(--text-on-dark-soft);
}

.page-faq .faq-contact__actions {
  margin-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

.page-faq .faq-contact__channels {
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line-on-dark);
}

.page-faq .faq-channel {
  display: grid;
  gap: 0.45rem;
  justify-items: start;
  padding: 1.15rem 0;
  border-bottom: 1px solid var(--line-on-dark);
}

.page-faq .faq-channel__label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--c-brass);
}

.page-faq .faq-channel__value {
  font-size: 1.0625rem;
  letter-spacing: 0.02em;
  color: var(--text-on-dark);
  word-break: break-all;
}

.page-faq .faq-channel__hint {
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--text-on-dark-soft);
}

.page-faq .faq-copy {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 0.3rem;
  padding: 0.48rem 0.9rem;
  border: 1px solid var(--line-on-dark-strong);
  background-color: transparent;
  font-family: inherit;
  font-size: 0.8125rem;
  line-height: 1.4;
  color: var(--text-on-dark);
  cursor: pointer;
  transition: border-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease), background-color var(--t-fast) var(--ease);
}

.page-faq .faq-copy:hover,
.page-faq .faq-copy:focus-visible {
  border-color: var(--c-brass-lit);
  color: var(--c-brass-lit);
  background-color: rgba(216, 174, 99, 0.08);
}

.page-faq .faq-copy.is-copied {
  border-color: var(--c-brass-lit);
  color: var(--c-brass-lit);
}

.page-faq .faq-mailtip {
  padding: 1.2rem 0 0;
}

.page-faq .faq-mailtip__title {
  margin: 0 0 0.85rem;
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--text-on-dark);
}

.page-faq .faq-mailtip__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background-color: var(--line-on-dark);
  border: 1px solid var(--line-on-dark);
}

.page-faq .faq-mailtip__list li {
  display: grid;
  gap: 0.5rem;
  justify-items: start;
  padding: 1rem 1.1rem 1.1rem;
  background-color: var(--c-ink);
}

.page-faq .faq-mailtip__case {
  font-size: 0.8125rem;
  color: var(--text-on-dark-soft);
}

.page-faq .faq-mailtip__fmt {
  font-size: 0.9375rem;
  letter-spacing: 0.04em;
  color: var(--c-brass-lit);
  word-break: break-all;
}

.page-faq .faq-mailtip__note {
  margin: 0.9rem 0 0;
  font-size: 0.8125rem;
  line-height: 1.8;
  color: var(--text-on-dark-soft);
}

/* ===== 响应式 ===== */
@media (min-width: 640px) {
  .page-faq .faq-index__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-faq .faq-toolbar__inner {
    grid-template-columns: minmax(0, 1fr);
  }

  .page-faq .faq-mailtip__list li {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    column-gap: 1rem;
  }

  .page-faq .faq-mailtip__case {
    grid-column: 1 / -1;
  }

  .page-faq .faq-mailtip__fmt {
    grid-column: 1;
  }

  .page-faq .faq-mailtip__list .faq-copy {
    grid-column: 2;
    margin-top: 0;
  }
}

@media (min-width: 900px) {
  .page-faq .faq-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: end;
    gap: clamp(2rem, 4vw, 3.5rem);
  }

  .page-faq .faq-toolbar__inner {
    grid-template-columns: minmax(0, 22rem) minmax(0, 1fr);
    align-items: end;
    gap: 1.75rem;
  }

  .page-faq .faq-filters {
    justify-content: flex-end;
  }

  .page-faq .faq-contact__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(2rem, 5vw, 4rem);
    align-items: start;
  }
}

@media (min-width: 1080px) {
  .page-faq .faq-index__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 1120px) {
  .page-faq .faq-body__grid {
    grid-template-columns: var(--faq-rail-w) minmax(0, 1fr);
    gap: clamp(2.5rem, 5vw, 4rem);
    align-items: start;
  }

  .page-faq .faq-rail {
    position: sticky;
    top: var(--faq-sticky-top);
  }
}

@media (max-width: 600px) {
  .page-faq .faq-item__a {
    padding-left: 1.05rem;
    padding-right: 1.05rem;
  }

  .page-faq .faq-item__num {
    min-width: 2.5em;
  }

  .page-faq .faq-hero__facts li {
    grid-template-columns: 2.8rem minmax(0, 1fr);
    gap: 0.7rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-faq .faq-card,
  .page-faq .faq-item,
  .page-faq .faq-item__q,
  .page-faq .faq-item__num,
  .page-faq .faq-item__icon::before,
  .page-faq .faq-item__icon::after,
  .page-faq .faq-copy,
  .page-faq .faq-filters a,
  .page-faq .faq-search__field {
    transition-duration: 0.01ms;
  }
}