.page-faq {
  background: var(--void);
  color: var(--silver);
  font-family: var(--font-body);
  font-size: var(--step-3);
  line-height: 1.85;
}

/* ---------- 页头 ---------- */
.page-faq .faq-head {
  position: relative;
  padding: clamp(28px, 5vw, 56px) 0 clamp(28px, 5vw, 48px);
  border-bottom: 1px solid var(--grid);
  background: linear-gradient(180deg, var(--hull) 0%, var(--void) 100%);
}

.page-faq .faq-head::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  background: repeating-linear-gradient(90deg, var(--grid) 0 1px, transparent 1px 14px);
}

.page-faq .faq-head__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px 24px;
  margin: 22px 0 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--grid);
}

.page-faq .faq-edition {
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
  color: var(--steel);
  margin: 0;
}

.page-faq .faq-edition__num {
  color: var(--amber);
}

.page-faq .faq-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2rem, 5.4vw, 3.4rem);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--paper);
  margin: 0 0 20px;
  max-width: 18em;
}

.page-faq .faq-lede {
  max-width: 34em;
  margin: 0;
  color: var(--steel);
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.9;
}

.page-faq .faq-facts {
  list-style: none;
  margin: clamp(26px, 4vw, 38px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  border-top: 1px solid var(--grid);
  border-bottom: 1px solid var(--grid);
}

.page-faq .faq-facts li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 4px;
  border-top: 1px solid var(--grid);
}

.page-faq .faq-facts li:first-child {
  border-top: 0;
}

.page-faq .faq-facts__k {
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.08em;
  color: var(--steel);
}

.page-faq .faq-facts__v {
  font-family: var(--font-mono);
  font-size: var(--step-2);
  font-weight: 700;
  letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums;
  color: var(--amber);
}

/* ---------- 索引示意图 ---------- */
.page-faq .faq-visual {
  padding: clamp(26px, 4vw, 44px) 0 0;
}

.page-faq .faq-visual__frame img,
.page-faq .faq-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--grid);
}

/* ---------- 口径说明 ---------- */
.page-faq .faq-basis {
  padding: clamp(34px, 6vw, 64px) 0;
  border-bottom: 1px solid var(--grid);
}

.page-faq .faq-basis__inner {
  max-width: 46em;
  padding-left: clamp(0px, 3vw, 28px);
  border-left: 1px solid var(--grid);
}

.page-faq .faq-h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.35rem, 3vw, 1.9rem);
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--paper);
  margin: 14px 0 18px;
}

.page-faq .faq-basis__text {
  margin: 0 0 18px;
  max-width: 34em;
  color: var(--steel);
  font-size: var(--step-3);
  line-height: 1.9;
}

.page-faq .faq-basis__link {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.06em;
  color: var(--amber);
  text-decoration: none;
  border-bottom: 1px solid var(--grid);
  padding-bottom: 4px;
  transition: border-color 0.3s var(--ease), color 0.3s var(--ease);
}

.page-faq .faq-basis__link:hover,
.page-faq .faq-basis__link:focus-visible {
  color: var(--amber-soft);
  border-bottom-color: var(--amber);
}

/* ---------- 主体两栏 ---------- */
.page-faq .faq-body {
  padding: clamp(34px, 6vw, 64px) 0 clamp(40px, 7vw, 76px);
}

.page-faq .faq-body__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px 48px;
}

.page-faq .faq-rail {
  border-top: 1px solid var(--grid);
  padding-top: 18px;
}

.page-faq .faq-rail__head {
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.14em;
  color: var(--steel);
  margin: 0 0 14px;
}

.page-faq .faq-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  border-left: 1px solid var(--grid);
}

.page-faq .faq-rail__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 10px 10px 14px;
  color: var(--silver);
  text-decoration: none;
  font-size: var(--step-2);
  border-bottom: 1px solid var(--grid);
  transition: color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.page-faq .faq-rail__link:hover,
.page-faq .faq-rail__link:focus-visible {
  color: var(--amber-soft);
  box-shadow: inset 3px 0 0 var(--amber);
}

.page-faq .faq-rail__num {
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
  color: var(--amber);
}

.page-faq .faq-rail__foot {
  margin: 18px 0 0;
  padding-left: 14px;
  font-size: var(--step-2);
  line-height: 1.8;
  color: var(--steel);
  max-width: 24em;
}

/* ---------- 问答块 ---------- */
.page-faq .faq-items {
  display: grid;
  gap: 0;
  min-width: 0;
}

.page-faq .faq-item {
  border-top: 1px solid var(--grid);
  scroll-margin-top: 110px;
  padding: 6px 0 22px;
}

.page-faq .faq-item:last-child {
  border-bottom: 1px solid var(--grid);
}

.page-faq .faq-item__summary {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  gap: 6px 14px;
  padding: 16px 0 14px;
}

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

.page-faq .faq-item__num {
  font-family: var(--font-mono);
  font-size: var(--step-2);
  letter-spacing: 0.08em;
  font-variant-numeric: tabular-nums;
  color: var(--amber);
}

.page-faq .faq-item__label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.15rem, 2.6vw, 1.5rem);
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-faq .faq-item__hint {
  grid-column: 2 / -1;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.08em;
  color: var(--steel);
}

.page-faq .faq-item[open] .faq-item__label {
  color: var(--amber-soft);
}

.page-faq .faq-item__body {
  padding: 4px 0 0;
}

.page-faq .faq-item__conclusion {
  margin: 0;
  padding-left: 16px;
  border-left: 2px solid var(--grid);
  font-size: clamp(17px, 2.2vw, 21px);
  line-height: 1.72;
  font-weight: 500;
  color: var(--paper);
  max-width: 30em;
}

.page-faq .faq-steps {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  border-top: 1px solid var(--grid);
}

.page-faq .faq-steps li {
  display: grid;
  grid-template-columns: 30px 1fr;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px solid var(--grid);
  font-size: var(--step-2);
  line-height: 1.8;
  color: var(--steel);
}

.page-faq .faq-steps__num {
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
  color: var(--amber);
  padding-top: 5px;
}

.page-faq .faq-item__aside {
  margin: 16px 0 0;
  padding-left: 16px;
  border-left: 1px solid var(--grid);
  font-size: var(--step-2);
  line-height: 1.85;
  color: var(--steel);
  max-width: 34em;
}

.page-faq .faq-item__more {
  margin: 14px 0 0;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.06em;
}

.page-faq .faq-item__more a {
  color: var(--amber);
  text-decoration: none;
  border-bottom: 1px solid var(--grid);
  padding-bottom: 3px;
  transition: border-color 0.3s var(--ease), color 0.3s var(--ease);
}

.page-faq .faq-item__more a:hover,
.page-faq .faq-item__more a:focus-visible {
  color: var(--amber-soft);
  border-bottom-color: var(--amber);
}

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

.page-faq .faq-figure__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.06em;
  color: var(--steel);
}

/* ---------- 边界区块 ---------- */
.page-faq .faq-boundary {
  padding: 0 0 clamp(48px, 8vw, 88px);
}

.page-faq .faq-boundary__inner {
  background: var(--hull);
  border: 1px solid var(--grid);
  border-left: 3px solid var(--amber);
  padding: clamp(26px, 4vw, 44px) clamp(20px, 4vw, 48px);
}

.page-faq .faq-boundary__text {
  max-width: 34em;
  margin: 0 0 20px;
  color: var(--steel);
  font-size: var(--step-3);
  line-height: 1.9;
}

.page-faq .faq-boundary__list {
  list-style: none;
  margin: 0 0 26px;
  padding: 0;
  border-top: 1px solid var(--grid);
}

.page-faq .faq-boundary__list li {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 12px;
  padding: 11px 0;
  border-bottom: 1px solid var(--grid);
  font-size: var(--step-2);
  line-height: 1.8;
  color: var(--silver);
}

.page-faq .faq-boundary__list .mono {
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
  color: var(--amber);
  padding-top: 5px;
}

/* ---------- 平板 ---------- */
@media (min-width: 720px) {
  .page-faq .faq-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-faq .faq-facts li {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 18px 20px;
    border-top: 0;
    border-left: 1px solid var(--grid);
  }

  .page-faq .faq-facts li:first-child {
    border-left: 0;
  }

  .page-faq .faq-item__summary {
    grid-template-columns: auto 1fr auto;
    align-items: baseline;
  }

  .page-faq .faq-item__hint {
    grid-column: 3 / 4;
    text-align: right;
  }
}

/* ---------- 桌面：sticky 索引 + 展开问答 ---------- */
@media (min-width: 980px) {
  .page-faq .faq-body__grid {
    grid-template-columns: 236px minmax(0, 1fr);
    gap: 0 56px;
    align-items: start;
  }

  .page-faq .faq-rail {
    position: sticky;
    top: 108px;
    align-self: start;
    border-top: 0;
    padding-top: 0;
  }

  .page-faq .faq-rail__list {
    grid-template-columns: 1fr;
  }

  .page-faq .faq-rail__link {
    font-size: var(--step-2);
  }

  .page-faq .faq-items {
    border-left: 1px solid var(--grid);
    padding-left: 48px;
  }

  .page-faq .faq-item:first-child {
    border-top: 0;
    padding-top: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-faq .faq-rail__link,
  .page-faq .faq-item__more a,
  .page-faq .faq-basis__link {
    transition: none;
  }
}
<<<END>>>