/* ============ page-faq ============ */
.page-faq {
  --faq-rail: 216px;
  --faq-gap: clamp(1.6rem, 4vw, 3.2rem);
  padding-bottom: clamp(2.4rem, 6vw, 4rem);
}

/* ---------- 首屏声明段 ---------- */
.page-faq .faq-hero {
  position: relative;
  padding-top: clamp(1.4rem, 4.5vw, 3rem);
  overflow: hidden;
}

.page-faq .faq-hero::after {
  content: "";
  position: absolute;
  top: -18rem;
  right: -12rem;
  width: 42rem;
  height: 34rem;
  border-radius: 50%;
  background: radial-gradient(closest-side, rgba(47, 224, 200, 0.13), rgba(4, 18, 14, 0) 72%);
  pointer-events: none;
  animation: faq-drift 24s cubic-bezier(0.22, 0.61, 0.36, 1) infinite alternate;
}

@keyframes faq-drift {
  from { transform: translate3d(0, 0, 0); }
  to { transform: translate3d(-3rem, 2rem, 0); }
}

.page-faq .faq-hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(1.4rem, 3.4vw, 2.4rem);
  padding-bottom: clamp(1.6rem, 4vw, 2.8rem);
}

.page-faq .faq-hero-main {
  display: grid;
  gap: 0.85rem;
  min-width: 0;
}

.page-faq .breadcrumb {
  margin-bottom: 0.2rem;
}

.page-faq .faq-hero .display-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2.6rem, 7vw, 5.6rem);
  font-weight: 300;
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-faq .faq-hero .lede {
  margin: 0;
  max-width: 34em;
  font-size: 0.95rem;
  line-height: 1.78;
  color: rgba(234, 245, 241, 0.76);
}

.page-faq .faq-hero-side {
  border-top: 1px solid var(--hair);
  padding-top: 0.9rem;
  min-width: 0;
}

.page-faq .faq-hero-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.55rem;
}

.page-faq .faq-hero-list li {
  display: flex;
  align-items: baseline;
  gap: 0.65rem;
  font-size: 0.8rem;
  letter-spacing: 0.03em;
  color: var(--muted);
}

.page-faq .faq-hero-list .num {
  flex: none;
  min-width: 3.2ch;
  font-family: var(--font-mono);
  font-size: 1.08rem;
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
}

/* ---------- 顶部窄幅横带 ---------- */
.page-faq .faq-band {
  margin: 0;
  border-top: 1px solid var(--hair);
  border-bottom: 1px solid var(--hair);
}

.page-faq .faq-band img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  max-width: 100%;
  opacity: 0.62;
}

/* ---------- 分栏主体 ---------- */
.page-faq .faq-body {
  display: grid;
  gap: var(--faq-gap);
  padding-top: clamp(2.2rem, 5vw, 3.6rem);
}

/* 左侧索引 */
.page-faq .faq-rail {
  min-width: 0;
}

.page-faq .faq-rail-label {
  margin: 0 0 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-faq .faq-index {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.page-faq .faq-index-link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.55rem;
  min-height: 44px;
  padding: 0.55rem 0.85rem;
  border: 1px solid var(--hair-soft);
  border-radius: 2px;
  color: var(--muted);
  font-size: 0.82rem;
  letter-spacing: 0.02em;
  text-decoration: none;
  background: rgba(8, 31, 25, 0.35);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease),
    background var(--dur) var(--ease);
}

.page-faq .faq-index-link:hover,
.page-faq .faq-index-link:focus-visible {
  color: var(--mist);
  border-color: var(--cyan);
  background: rgba(18, 53, 44, 0.6);
}

.page-faq .faq-index-num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--cyan);
  opacity: 0.85;
}

.page-faq .faq-rail-figure {
  display: none;
  margin: 1.4rem 0 0;
}

.page-faq .faq-rail-figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  max-width: 100%;
  opacity: 0.8;
}

/* 右侧问答组 */
.page-faq .faq-groups {
  min-width: 0;
}

.page-faq .faq-group {
  scroll-margin-top: 6.5rem;
}

.page-faq .faq-group + .faq-group {
  margin-top: clamp(2.6rem, 6vw, 4.2rem);
}

.page-faq .faq-group-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  column-gap: 0.9rem;
  row-gap: 0.45rem;
  margin-bottom: 0.4rem;
}

.page-faq .faq-group-index {
  grid-column: 1;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-faq .faq-group-title {
  grid-column: 2;
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 3.4vw, 2rem);
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-faq .faq-group-note {
  grid-column: 1 / -1;
  margin: 0;
  max-width: 34em;
  font-size: 0.8rem;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 可展开问答 ---------- */
.page-faq .fold-group {
  border-top: 1px solid var(--hair);
}

.page-faq .fold {
  border-bottom: 1px solid var(--hair-soft);
}

.page-faq .fold-head {
  position: relative;
  width: 100%;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.2rem;
  margin: 0;
  padding: 1.15rem 0 1.15rem 0.95rem;
  background: transparent;
  border: 0;
  color: var(--white);
  font-family: var(--font-body);
  font-size: 0.98rem;
  font-weight: 400;
  line-height: 1.55;
  text-align: left;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  transition: color var(--dur) var(--ease);
}

.page-faq .fold-head::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.4rem;
  bottom: 1.4rem;
  width: 1px;
  background: var(--edge);
  transition: background var(--dur) var(--ease), width var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.page-faq .fold-head[aria-expanded="true"]::before {
  width: 2px;
  background: var(--cyan);
  box-shadow: 0 0 10px rgba(47, 224, 200, 0.5);
}

.page-faq .fold-head:hover {
  color: var(--mist);
}

.page-faq .fold-head:focus-visible {
  outline: 1px solid var(--cyan);
  outline-offset: 2px;
}

.page-faq .fold-title {
  min-width: 0;
}

.page-faq .fold-sign {
  position: relative;
  flex: none;
  width: 14px;
  height: 14px;
  margin-top: 0.4rem;
}

.page-faq .fold-sign::before,
.page-faq .fold-sign::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1px;
  background: var(--muted);
  transform: translateY(-50%);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease),
    background var(--dur) var(--ease);
}

.page-faq .fold-sign::after {
  transform: translateY(-50%) rotate(90deg);
}

.page-faq .fold-head[aria-expanded="true"] .fold-sign::before {
  background: var(--cyan);
}

.page-faq .fold-head[aria-expanded="true"] .fold-sign::after {
  transform: translateY(-50%) rotate(0deg);
  opacity: 0;
}

.page-faq .fold-body {
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  padding-left: 0.95rem;
  padding-bottom: 0;
  transition: max-height var(--dur) var(--ease), opacity var(--dur) var(--ease),
    padding-bottom var(--dur) var(--ease);
}

.page-faq .fold-head[aria-expanded="true"] + .fold-body {
  max-height: 60rem;
  opacity: 1;
  padding-bottom: 1.4rem;
}

.page-faq .fold-body p {
  margin: 0 0 0.75rem;
  max-width: 34em;
  font-size: 0.93rem;
  line-height: 1.78;
  color: rgba(234, 245, 241, 0.86);
}

.page-faq .fold-body p:last-child {
  margin-bottom: 0;
}

.page-faq .fold-body ul {
  margin: 0 0 0.75rem;
  padding-left: 1.05rem;
  max-width: 34em;
}

.page-faq .fold-body li {
  margin-bottom: 0.3rem;
  font-size: 0.9rem;
  line-height: 1.72;
  color: rgba(234, 245, 241, 0.8);
}

.page-faq .fold-body li::marker {
  color: var(--cyan);
}

.page-faq .fold-body .note {
  max-width: 34em;
  font-size: 0.72rem;
  font-weight: 300;
  line-height: 1.7;
  color: var(--muted);
}

.page-faq .fold-body .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--mist);
}

/* ---------- 延伸段 ---------- */
.page-faq .faq-cta {
  margin-top: clamp(2.8rem, 7vw, 5rem);
  border-top: 1px solid var(--hair);
  background:
    linear-gradient(180deg, rgba(4, 18, 14, 0) 0%, rgba(18, 53, 44, 0.62) 100%),
    radial-gradient(120% 90% at 90% 0%, rgba(255, 90, 31, 0.1), rgba(4, 18, 14, 0) 60%);
}

.page-faq .faq-cta-inner {
  display: grid;
  gap: clamp(1.6rem, 3.4vw, 2.6rem);
  padding: clamp(2rem, 5vw, 3.4rem) 0 clamp(2.2rem, 5vw, 3.6rem);
}

.page-faq .faq-cta-main {
  display: grid;
  gap: 0.75rem;
  justify-items: start;
  min-width: 0;
}

.page-faq .faq-cta-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 4vw, 2.3rem);
  font-weight: 300;
  line-height: 1.16;
  letter-spacing: -0.015em;
  color: var(--white);
}

.page-faq .faq-cta-text {
  margin: 0;
  max-width: 34em;
  font-size: 0.93rem;
  line-height: 1.78;
  color: var(--muted);
}

.page-faq .faq-cta-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.8rem;
  margin: 0.5rem 0 0;
}

.page-faq .faq-links {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--hair-soft);
  min-width: 0;
}

.page-faq .faq-links li {
  border-bottom: 1px solid var(--hair-soft);
}

.page-faq .faq-links a {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  min-height: 44px;
  padding: 0.85rem 0;
  color: var(--white);
  font-size: 0.9rem;
  letter-spacing: 0.01em;
  text-decoration: none;
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}

.page-faq .faq-links a span {
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

.page-faq .faq-links a:hover,
.page-faq .faq-links a:focus-visible {
  color: var(--mist);
  padding-left: 0.4rem;
}

/* ---------- 桌面端 ---------- */
@media (min-width: 900px) {
  .page-faq .faq-hero-inner {
    grid-template-columns: minmax(0, 3fr) minmax(0, 1fr);
    align-items: end;
    column-gap: var(--faq-gap);
  }

  .page-faq .faq-hero-side {
    border-top: 0;
    border-left: 1px solid var(--hair);
    padding-top: 0;
    padding-left: 1.5rem;
    padding-bottom: 0.5rem;
  }

  .page-faq .faq-body {
    grid-template-columns: var(--faq-rail) minmax(0, 1fr);
    column-gap: clamp(2rem, 4vw, 4.2rem);
    align-items: start;
  }

  .page-faq .faq-rail {
    position: sticky;
    top: 6.5rem;
  }

  .page-faq .faq-index {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
    border-left: 1px solid var(--hair-soft);
  }

  .page-faq .faq-index-link {
    display: flex;
    align-items: baseline;
    justify-content: flex-start;
    position: relative;
    border: 0;
    border-radius: 0;
    background: none;
    padding: 0.62rem 0 0.62rem 0.95rem;
  }

  .page-faq .faq-index-link::before {
    content: "";
    position: absolute;
    left: -1px;
    top: 0.5rem;
    bottom: 0.5rem;
    width: 1px;
    background: transparent;
    transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
  }

  .page-faq .faq-index-link:hover::before,
  .page-faq .faq-index-link:focus-visible::before {
    background: var(--cyan);
    box-shadow: 0 0 8px rgba(47, 224, 200, 0.5);
  }

  .page-faq .faq-rail-figure {
    display: block;
  }

  .page-faq .faq-cta-inner {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    column-gap: var(--faq-gap);
    align-items: start;
  }
}

@media (min-width: 1160px) {
  .page-faq .faq-body {
    grid-template-columns: 248px minmax(0, 1fr);
  }
}

/* ---------- 降低动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-faq .faq-hero::after {
    animation: none;
  }

  .page-faq .fold-body,
  .page-faq .fold-head,
  .page-faq .fold-sign::before,
  .page-faq .fold-sign::after,
  .page-faq .faq-index-link,
  .page-faq .faq-links a {
    transition: none;
  }
}
</main>