.page-faq {
  --faq-sticky-top: 5.6rem;
  --faq-gap: clamp(1.5rem, 4vw, 3.5rem);
  position: relative;
  padding-bottom: clamp(3rem, 8vw, 6rem);
}

.page-faq__anchor {
  display: block;
  height: 0;
  margin: 0;
}

/* ---------- 首屏 ---------- */
.page-faq .page-faq__hero {
  position: relative;
  display: grid;
  gap: clamp(1.25rem, 4vw, 2.5rem);
  align-items: end;
  margin-bottom: clamp(2.25rem, 6vw, 3.75rem);
  padding-top: clamp(1rem, 3vw, 1.75rem);
}

.page-faq .page-faq__hero::before {
  content: "";
  position: absolute;
  inset: -1.5rem -6vw auto -6vw;
  height: 74%;
  background:
    linear-gradient(118deg,
      rgba(27, 58, 94, 0.85) 0%,
      rgba(58, 134, 255, 0.16) 48%,
      rgba(10, 14, 26, 0) 80%);
  clip-path: polygon(0 0, 100% 0, 100% 68%, 0 100%);
  z-index: 0;
  pointer-events: none;
}

.page-faq .page-faq__hero-copy,
.page-faq .page-faq__hero-figure {
  position: relative;
  z-index: 1;
}

.page-faq .page-faq__hero h1 {
  margin: 0.4rem 0 0.9rem;
  font-family: var(--ff-display);
  font-size: clamp(2rem, 6.6vw, 3.4rem);
  font-weight: 900;
  line-height: 1.03;
  letter-spacing: -0.012em;
  color: var(--text);
}

.page-faq .page-faq__lede {
  max-width: 54ch;
  margin: 0;
  color: var(--muted);
  font-size: clamp(0.95rem, 2.4vw, 1.05rem);
  line-height: 1.8;
}

.page-faq .page-faq__meta {
  margin: 1rem 0 0;
  color: var(--blue);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
}

.page-faq .page-faq__hero-figure {
  margin: 0;
  background: var(--panel);
  border: 1px solid var(--line);
  overflow: hidden;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), 0 100%);
}

.page-faq .page-faq__hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
}

/* ---------- 两栏骨架 ---------- */
.page-faq .page-faq__layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--faq-gap);
  align-items: start;
}

/* ---------- 左侧索引 ---------- */
.page-faq .page-faq__index {
  position: relative;
  border-top: 1px solid var(--line);
  padding-top: 0.85rem;
}

.page-faq .page-faq__index-title {
  margin: 0 0 0.6rem;
  color: var(--muted);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.page-faq .page-faq__index-list {
  display: flex;
  gap: 0.45rem;
  margin: 0;
  padding: 0 0 0.4rem;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.page-faq .page-faq__index-link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.45rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  color: var(--muted);
  font-size: 0.85rem;
  white-space: nowrap;
  text-decoration: none;
  transition: color 0.15s var(--ease), border-color 0.15s var(--ease),
    background-color 0.15s var(--ease);
}

.page-faq .page-faq__index-link:hover,
.page-faq .page-faq__index-link:focus-visible {
  color: var(--text);
  border-color: var(--neon);
  background: rgba(0, 255, 157, 0.07);
}

.page-faq .page-faq__index-no {
  color: var(--neon);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
}

/* ---------- 问答流 ---------- */
.page-faq .page-faq__stream {
  min-width: 0;
  display: grid;
  gap: clamp(2rem, 5vw, 3rem);
}

.page-faq .faq-section {
  scroll-margin-top: var(--faq-sticky-top);
}

.page-faq .faq-section__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  column-gap: 0.85rem;
  row-gap: 0.4rem;
  margin: 0 0 1.15rem;
  padding-top: 1.1rem;
  border-top: 1px solid var(--line);
}

.page-faq .faq-section__no {
  color: var(--neon);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
}

.page-faq .faq-section__title {
  margin: 0;
  font-family: var(--ff-serif);
  font-size: clamp(1.35rem, 3.6vw, 1.8rem);
  font-weight: 700;
  line-height: 1.25;
  color: var(--text);
}

.page-faq .faq-section__lede {
  grid-column: 2;
  margin: 0;
  max-width: 62ch;
  color: var(--muted);
  font-size: 0.93rem;
  line-height: 1.75;
}

.page-faq .faq-section--lead {
  position: relative;
  padding: clamp(1.1rem, 3vw, 1.6rem) clamp(1rem, 3vw, 1.6rem)
    clamp(0.9rem, 2.5vw, 1.3rem);
  background:
    linear-gradient(142deg,
      rgba(58, 134, 255, 0.16) 0%,
      rgba(18, 26, 46, 0.92) 44%,
      rgba(10, 14, 26, 0.45) 100%);
  border: 1px solid var(--line);
  border-radius: 6px;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 0 calc(100% - 20px));
}

.page-faq .faq-section--lead::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(180deg, var(--neon), var(--blue) 70%, transparent);
}

.page-faq .faq-section--lead .faq-section__head {
  border-top: 0;
  padding-top: 0;
}

/* ---------- 折叠问答 ---------- */
.page-faq .faq-section__items {
  display: grid;
  gap: 0.55rem;
}

.page-faq .qa {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.15s var(--ease), background-color 0.15s var(--ease);
}

.page-faq .qa:hover {
  border-color: rgba(58, 134, 255, 0.5);
}

.page-faq .qa[open] {
  border-color: rgba(0, 255, 157, 0.42);
  background: linear-gradient(160deg, rgba(0, 255, 157, 0.05), rgba(18, 26, 46, 1) 42%);
}

.page-faq .qa__q {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 0.8rem;
  padding: 0.9rem 1rem;
  cursor: pointer;
  list-style: none;
  color: var(--text);
}

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

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

.page-faq .qa__q:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: -3px;
}

.page-faq .qa__no {
  color: var(--muted);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  padding-top: 0.22rem;
}

.page-faq .qa__label {
  font-family: var(--ff-serif);
  font-size: 1rem;
  line-height: 1.5;
}

.page-faq .qa__mark {
  position: relative;
  align-self: center;
  width: 13px;
  height: 13px;
  flex: none;
}

.page-faq .qa__mark::before,
.page-faq .qa__mark::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1.6px;
  background: var(--neon);
  transition: transform 0.18s var(--ease), opacity 0.18s var(--ease);
}

.page-faq .qa__mark::after {
  transform: rotate(90deg);
}

.page-faq .qa[open] .qa__mark::after {
  transform: rotate(0deg);
  opacity: 0.35;
}

.page-faq .qa__body {
  padding: 0.75rem 1rem 1.05rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.93rem;
  line-height: 1.8;
}

.page-faq .qa__body p {
  margin: 0;
}

.page-faq .qa__body p + p {
  margin-top: 0.6rem;
}

.page-faq .qa__body a {
  color: var(--blue);
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

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

.page-faq .qa__body mark,
.page-faq .faq-section__lede mark {
  background: rgba(0, 255, 157, 0.13);
  color: var(--neon);
  padding: 0 0.2em;
  border-radius: 2px;
}

/* ---------- 流程插图 ---------- */
.page-faq .page-faq__flow {
  margin: 1.5rem 0 0;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-faq .page-faq__flow img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 5 / 3;
  object-fit: cover;
}

.page-faq .page-faq__flow-caption {
  padding: 0.7rem 1rem 0.85rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.65;
}

/* ---------- 术语对照 ---------- */
.page-faq .glossary {
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-faq .glossary__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.2rem;
  padding: 0.8rem 0.2rem;
  border-bottom: 1px solid var(--line);
}

.page-faq .glossary__term {
  margin: 0;
  font-family: var(--ff-serif);
  font-size: 1rem;
  font-weight: 700;
  color: var(--neon);
}

.page-faq .glossary__def {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.75;
}

/* ---------- 末尾提示 ---------- */
.page-faq .page-faq__footnote {
  margin: 1.4rem 0 0;
  padding: 0.9rem 1rem;
  background: rgba(18, 26, 46, 0.7);
  border-left: 3px solid var(--orange);
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.8;
}

.page-faq .page-faq__footnote a {
  color: var(--blue);
  text-underline-offset: 3px;
}

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

/* ---------- 回到顶部 ---------- */
.page-faq .page-faq__totop {
  display: none;
  position: fixed;
  right: clamp(1rem, 3vw, 2rem);
  bottom: clamp(1rem, 3vw, 2rem);
  z-index: 30;
  width: 44px;
  height: 44px;
  place-items: center;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--neon);
  font-size: 1.1rem;
  line-height: 1;
  text-decoration: none;
  transition: transform 0.15s var(--ease), border-color 0.15s var(--ease);
}

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

/* ---------- 平板及以上 ---------- */
@media (min-width: 820px) {
  .page-faq .page-faq__hero {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  }
}

/* ---------- 桌面端两栏 ---------- */
@media (min-width: 900px) {
  .page-faq .page-faq__layout {
    grid-template-columns: 224px minmax(0, 1fr);
  }

  .page-faq .page-faq__index {
    position: sticky;
    top: var(--faq-sticky-top);
    border-top: 0;
    padding-top: 0;
  }

  .page-faq .page-faq__index-list {
    flex-direction: column;
    gap: 0;
    padding-bottom: 0;
    overflow: visible;
  }

  .page-faq .page-faq__index-link {
    display: flex;
    padding: 0.6rem 0.2rem 0.6rem 0.85rem;
    border: 0;
    border-left: 2px solid var(--line);
    border-radius: 0;
    background: none;
    white-space: normal;
    font-size: 0.88rem;
  }

  .page-faq .page-faq__index-link:hover,
  .page-faq .page-faq__index-link:focus-visible {
    border-left-color: var(--neon);
    background: none;
  }

  .page-faq .glossary__row {
    grid-template-columns: minmax(130px, 190px) minmax(0, 1fr);
    gap: 1.25rem;
    align-items: baseline;
  }
}

@media (min-width: 1024px) {
  .page-faq .page-faq__totop {
    display: grid;
  }

  .page-faq .qa__q {
    padding: 1rem 1.15rem;
  }

  .page-faq .qa__body {
    padding: 0.85rem 1.15rem 1.2rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-faq .qa__mark::before,
  .page-faq .qa__mark::after,
  .page-faq .page-faq__totop,
  .page-faq .page-faq__index-link,
  .page-faq .qa {
    transition: none;
  }

  .page-faq .page-faq__totop:hover,
  .page-faq .page-faq__totop:focus-visible {
    transform: none;
  }
}