.page-faq {
  --faq-rule: rgba(198, 211, 222, 0.14);
  --faq-rule-strong: rgba(198, 211, 222, 0.3);
  --faq-card-bg: rgba(4, 16, 31, 0.42);
  --cat-accent: var(--lime);
  position: relative;
  display: block;
  overflow-x: hidden;
  padding-bottom: var(--chapter);
  background:
    radial-gradient(940px 540px at 92% -8%, rgba(55, 214, 224, 0.1), transparent 62%),
    radial-gradient(760px 460px at 0% 14%, rgba(85, 242, 160, 0.06), transparent 60%),
    var(--night);
  color: var(--cloud);
  font-family: var(--font-sans);
  font-size: var(--fs-16);
  line-height: 1.75;
}

.page-faq *,
.page-faq *::before,
.page-faq *::after {
  box-sizing: border-box;
}

/* ---------- 首屏 ---------- */

.page-faq .faq-hero {
  position: relative;
  padding-top: calc(var(--chapter) * 1.35);
  padding-bottom: calc(var(--chapter) * 0.82);
}

.page-faq .faq-hero::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: min(46vw, 460px);
  height: 3px;
  background: linear-gradient(90deg, var(--lime), rgba(85, 242, 160, 0));
  transform: skewX(-30deg);
  transform-origin: left bottom;
  opacity: 0.8;
}

.page-faq .faq-hero .breadcrumb {
  margin-bottom: 32px;
}

.page-faq .faq-hero__split {
  display: grid;
  grid-template-columns: 1fr;
  gap: calc(var(--gap) * 1.75);
}

.page-faq .faq-hero__title {
  margin: 16px 0 0;
  font-size: var(--fs-40);
  font-weight: 200;
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--cloud);
}

.page-faq .faq-hero__intro {
  margin: 28px 0 0;
  max-width: 62ch;
  font-size: var(--fs-16);
  line-height: 1.85;
  color: var(--silver);
}

.page-faq .faq-hero__intro::before {
  content: "";
  display: block;
  width: 44px;
  height: 2px;
  margin-bottom: 20px;
  background: var(--lime);
}

.page-faq .faq-hero__side {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-content: start;
}

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

.page-faq .faq-jump .eyebrow {
  margin: 0 0 14px;
}

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

.page-faq .faq-jump__link {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 11px 0;
  border-bottom: 1px solid var(--faq-rule);
  color: var(--silver);
  font-size: var(--fs-16);
  text-decoration: none;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-faq .faq-jump__link:hover,
.page-faq .faq-jump__link:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--line-lime);
}

.page-faq .faq-jump__num {
  font-family: var(--font-mono);
  font-size: var(--fs-11);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--slate);
  transition: color 160ms var(--ease);
}

.page-faq .faq-jump__link:hover .faq-jump__num,
.page-faq .faq-jump__link:focus-visible .faq-jump__num {
  color: var(--lime);
}

.page-faq .faq-facts {
  margin: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.page-faq .faq-facts__item {
  padding: 14px 0;
  border-top: 1px solid var(--faq-rule);
}

.page-faq .faq-facts__label {
  margin: 0 0 6px;
  font-size: var(--fs-11);
  letter-spacing: 0.28em;
  color: var(--slate);
}

.page-faq .faq-facts__value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-20);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
  color: var(--cloud);
}

/* ---------- 分类章节 ---------- */

.page-faq .faq-cat {
  position: relative;
  padding-top: calc(var(--chapter) * 0.72);
  padding-bottom: calc(var(--chapter) * 0.72);
  border-top: 1px solid var(--faq-rule);
}

.page-faq .faq-cat--scope {
  --cat-accent: var(--lime);
  background: linear-gradient(180deg, rgba(6, 49, 47, 0.62) 0%, rgba(6, 49, 47, 0) 66%);
}

.page-faq .faq-cat--schedule {
  --cat-accent: var(--cyan);
  background: linear-gradient(180deg, rgba(34, 26, 69, 0.62) 0%, rgba(34, 26, 69, 0) 66%);
}

.page-faq .faq-cat--usage {
  --cat-accent: var(--silver);
  background: linear-gradient(180deg, rgba(4, 16, 31, 0.72) 0%, rgba(4, 16, 31, 0) 66%);
}

.page-faq .faq-cat--fix {
  --cat-accent: var(--orange);
  background: linear-gradient(180deg, rgba(89, 24, 43, 0.58) 0%, rgba(89, 24, 43, 0) 66%);
}

.page-faq .faq-cat--terms {
  --cat-accent: var(--lime);
  background: linear-gradient(180deg, rgba(6, 49, 47, 0.5) 0%, rgba(6, 49, 47, 0) 70%);
}

.page-faq .faq-cat__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.page-faq .faq-cat__mark {
  display: block;
  width: 40px;
  height: 2px;
  margin-bottom: 18px;
  background: var(--cat-accent);
}

.page-faq .faq-cat__title {
  margin: 10px 0 0;
  font-size: var(--fs-28);
  font-weight: 200;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--cloud);
}

.page-faq .faq-cat__desc {
  margin: 18px 0 0;
  max-width: 48ch;
  font-size: var(--fs-13);
  line-height: 1.9;
  color: var(--slate);
}

.page-faq .faq-cat__main {
  display: flex;
  flex-direction: column;
  gap: 28px;
  min-width: 0;
}

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

/* ---------- 问答条目 ---------- */

.page-faq .qa-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.page-faq .qa {
  border: 1px solid var(--faq-rule);
  background: var(--faq-card-bg);
  clip-path: var(--clip-card);
  transition: border-color 180ms var(--ease), background-color 180ms var(--ease);
}

.page-faq .qa[open] {
  border-color: var(--faq-rule-strong);
  background: rgba(6, 49, 47, 0.34);
}

.page-faq .qa__summary {
  display: grid;
  grid-template-columns: 26px minmax(0, 1fr) 20px;
  gap: 14px;
  align-items: start;
  padding: 18px;
  cursor: pointer;
  list-style: none;
}

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

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

.page-faq .qa__index {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: var(--fs-13);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--cat-accent);
}

.page-faq .qa__text {
  display: block;
  min-width: 0;
}

.page-faq .qa__question {
  display: block;
  font-size: var(--fs-20);
  font-weight: 400;
  line-height: 1.5;
  color: var(--cloud);
}

.page-faq .qa__digest {
  display: block;
  margin-top: 8px;
  font-size: var(--fs-13);
  line-height: 1.75;
  color: var(--slate);
  transition: color 180ms var(--ease);
}

.page-faq .qa[open] .qa__digest {
  color: var(--silver);
}

.page-faq .qa__toggle {
  position: relative;
  justify-self: end;
  width: 16px;
  height: 16px;
  margin-top: 8px;
}

.page-faq .qa__toggle::before,
.page-faq .qa__toggle::after {
  content: "";
  position: absolute;
  background: var(--silver);
  transition: transform 180ms var(--ease), background-color 180ms var(--ease);
}

.page-faq .qa__toggle::before {
  left: 0;
  top: 7px;
  width: 16px;
  height: 2px;
}

.page-faq .qa__toggle::after {
  left: 7px;
  top: 0;
  width: 2px;
  height: 16px;
}

.page-faq .qa[open] .qa__toggle::before {
  background: var(--cat-accent);
}

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

.page-faq .qa__body {
  margin-top: 2px;
  padding: 16px 18px 22px 18px;
  border-top: 1px dashed var(--faq-rule);
}

.page-faq .qa__body p {
  margin: 0 0 16px;
  max-width: 68ch;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: var(--cloud);
}

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

.page-faq .qa__links {
  margin-top: 4px;
}

.page-faq .link-inline {
  display: inline-block;
  color: var(--silver);
  font-size: var(--fs-13);
  text-decoration: none;
  border-bottom: 1px solid var(--line-strong);
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-faq .link-inline::before {
  content: "";
  display: inline-block;
  width: 0;
  height: 1px;
  margin-right: 0;
  vertical-align: middle;
  background: var(--lime);
  transition: width 180ms var(--ease), margin-right 180ms var(--ease);
}

.page-faq .link-inline:hover,
.page-faq .link-inline:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--line-lime);
}

.page-faq .link-inline:hover::before,
.page-faq .link-inline:focus-visible::before {
  width: 6px;
  margin-right: 6px;
}

.page-faq .link-inline:active {
  filter: brightness(0.92);
}

/* ---------- 术语速查 ---------- */

.page-faq .faq-terms__visual {
  margin: 28px 0 0;
}

.page-faq .term-grid {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.page-faq .term-card {
  padding: 16px 18px;
  border: 1px solid var(--faq-rule);
  background: var(--faq-card-bg);
  clip-path: var(--clip-card);
  transition: border-color 180ms var(--ease), background-color 180ms var(--ease);
}

.page-faq .term-card:hover,
.page-faq .term-card:focus-within {
  border-color: var(--line-lime);
  background: rgba(6, 49, 47, 0.5);
}

.page-faq .term-card__name {
  margin: 0 0 10px;
  padding-left: 10px;
  border-left: 2px solid var(--silver);
  font-family: var(--font-mono);
  font-size: var(--fs-16);
  font-weight: 600;
  line-height: 1.4;
  color: var(--cloud);
}

.page-faq .term-card__def {
  margin: 0;
  font-size: var(--fs-13);
  line-height: 1.78;
  color: var(--slate);
}

.page-faq .term-card__where {
  margin: 12px 0 0;
  font-size: var(--fs-11);
  letter-spacing: 0.1em;
  color: var(--cyan);
  opacity: 0;
  transition: opacity 180ms var(--ease);
}

.page-faq .term-card:hover .term-card__where,
.page-faq .term-card:focus-within .term-card__where {
  opacity: 1;
}

@media (hover: none) {
  .page-faq .term-card__where {
    opacity: 0.8;
  }
}

/* ---------- 右侧章节轨迹 ---------- */

.page-faq .index-rail {
  position: fixed;
  right: 18px;
  top: 50%;
  z-index: 20;
  display: none;
  flex-direction: column;
  gap: 16px;
  transform: translateY(-50%);
}

.page-faq .index-rail::before {
  content: "";
  position: absolute;
  left: 50%;
  top: -16px;
  bottom: -16px;
  width: 1px;
  transform: translateX(-50%);
  background: var(--faq-rule-strong);
}

.page-faq .index-rail__node {
  position: relative;
  display: block;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  border: 1px solid var(--silver);
  background: var(--night);
  transition: background-color 180ms var(--ease), border-color 180ms var(--ease), transform 180ms var(--ease);
}

.page-faq .index-rail__node:hover,
.page-faq .index-rail__node:focus-visible {
  border-color: var(--lime);
}

.page-faq .index-rail__node[aria-current="true"] {
  background: var(--lime);
  border-color: var(--lime);
  transform: scale(1.4);
}

/* ---------- 图片容器补偿 ---------- */

.page-faq .media-frame img {
  display: block;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-faq .media-frame--square img {
  width: 100%;
  aspect-ratio: 1 / 1;
}

.page-faq .media-frame--wide img {
  width: 100%;
  aspect-ratio: 3 / 2;
}

.page-faq .media-frame__caption {
  display: block;
  margin-top: 12px;
  font-size: var(--fs-11);
  line-height: 1.8;
  letter-spacing: 0.02em;
  color: var(--slate);
}

/* ---------- 响应式 ---------- */

@media (min-width: 560px) and (max-width: 919px) {
  .page-faq .faq-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 20px;
  }
}

@media (min-width: 600px) {
  .page-faq .qa__summary {
    grid-template-columns: 34px minmax(0, 1fr) 20px;
    gap: 16px;
    padding: 20px 22px;
  }

  .page-faq .qa__body {
    padding: 20px 22px 26px 72px;
  }
}

@media (min-width: 640px) {
  .page-faq .faq-hero__title {
    font-size: var(--fs-56);
  }

  .page-faq .faq-cat__title {
    font-size: var(--fs-28);
  }

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

@media (min-width: 920px) {
  .page-faq .faq-hero__split {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: calc(var(--gap) * 2.5);
    align-items: start;
  }

  .page-faq .faq-hero__side {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 40px;
    padding-top: 6px;
    padding-left: 40px;
    border-left: 1px solid var(--faq-rule);
  }

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

  .page-faq .faq-facts__value {
    font-size: var(--fs-28);
  }

  .page-faq .faq-cat__inner {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 56px;
    align-items: start;
  }

  .page-faq .faq-cat__title {
    font-size: var(--fs-40);
  }

  .page-faq .qa__summary {
    padding: 22px 24px;
  }

  .page-faq .qa__body {
    padding: 22px 24px 28px 82px;
  }

  .page-faq .faq-terms__visual {
    margin-top: 32px;
  }
}

@media (min-width: 1100px) {
  .page-faq .faq-hero__title {
    font-size: var(--fs-72);
  }
}

@media (min-width: 1400px) {
  .page-faq .index-rail {
    display: flex;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-faq .qa,
  .page-faq .qa__digest,
  .page-faq .qa__toggle::before,
  .page-faq .qa__toggle::after,
  .page-faq .link-inline,
  .page-faq .link-inline::before,
  .page-faq .faq-jump__link,
  .page-faq .faq-jump__num,
  .page-faq .term-card,
  .page-faq .term-card__where,
  .page-faq .index-rail__node {
    transition: none;
  }
}