.page-faq {
  --kb-gap: clamp(16px, 2.6vw, 36px);
  --kb-pad: clamp(16px, 2.2vw, 26px);
  --kb-wash: rgba(18, 53, 45, 0.46);
  --kb-wash-strong: rgba(18, 53, 45, 0.78);
  position: relative;
  color: var(--sy-on-dark);
  background: var(--sy-ink);
  padding-bottom: clamp(48px, 7vw, 112px);
  font-family: var(--sy-body);
  overflow-wrap: break-word;
}

.page-faq .kb-link {
  color: var(--sy-lime);
  text-decoration: none;
  border-bottom: 1px solid rgba(184, 255, 63, 0.42);
  transition: border-color 0.2s var(--sy-ease), color 0.2s var(--sy-ease);
}

.page-faq .kb-link:hover,
.page-faq .kb-link:focus-visible {
  color: var(--sy-mint);
  border-bottom-color: var(--sy-mint);
}

/* ---------- 首屏 ---------- */
.page-faq .kb-hero {
  position: relative;
  overflow: hidden;
  padding-top: calc(var(--sy-header-h) + clamp(20px, 4vw, 48px));
  padding-bottom: clamp(34px, 5vw, 68px);
  border-bottom: 1px solid var(--sy-line);
  background:
    radial-gradient(circle at 84% 4%, rgba(184, 255, 63, 0.12), transparent 46%),
    linear-gradient(180deg, var(--sy-charcoal), var(--sy-ink) 82%);
}

.page-faq .kb-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(174, 184, 179, 0.1) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(174, 184, 179, 0.1) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: radial-gradient(ellipse at 26% 18%, #000 18%, transparent 76%);
  mask-image: radial-gradient(ellipse at 26% 18%, #000 18%, transparent 76%);
}

.page-faq .kb-hero .sy-container {
  position: relative;
  z-index: 1;
}

.page-faq .kb-hero__grid {
  display: grid;
  gap: var(--kb-gap);
  margin-top: clamp(18px, 3vw, 32px);
}

.page-faq .kb-hero__copy {
  min-width: 0;
}

.page-faq .kb-hero__title {
  font-family: var(--sy-display);
  font-weight: 800;
  font-size: clamp(32px, 6vw, 62px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--sy-paper);
  margin: 14px 0 18px;
}

.page-faq .kb-hero__lead {
  font-size: clamp(15px, 1.6vw, 18px);
  line-height: 1.78;
  color: var(--sy-on-dark);
  max-width: 46ch;
  margin: 0 0 22px;
}

.page-faq .kb-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-faq .kb-hero__figure {
  margin: 0;
  min-width: 0;
}

.page-faq .kb-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--sy-line-strong);
  border-radius: var(--sy-radius);
  background: var(--sy-glass);
}

/* ---------- 步骤区 ---------- */
.page-faq .kb-steps {
  position: relative;
  padding: clamp(34px, 5vw, 76px) 0;
  border-bottom: 1px solid var(--sy-line);
  background: linear-gradient(180deg, var(--sy-charcoal), var(--sy-ink) 74%);
}

.page-faq .kb-steps__head {
  max-width: 62ch;
  margin-bottom: clamp(22px, 3vw, 36px);
}

.page-faq .kb-steps__num {
  display: inline-block;
  font-family: var(--sy-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--sy-orange);
  border-left: 2px solid var(--sy-orange);
  padding-left: 10px;
  margin-bottom: 12px;
}

.page-faq .kb-steps__title {
  font-family: var(--sy-display);
  font-weight: 800;
  font-size: clamp(24px, 3.6vw, 38px);
  line-height: 1.16;
  letter-spacing: -0.015em;
  color: var(--sy-paper);
  margin: 0 0 12px;
}

.page-faq .kb-steps__lead {
  font-size: 15px;
  line-height: 1.8;
  color: var(--sy-on-dark-soft);
  margin: 0;
}

.page-faq .kb-steps__grid {
  display: grid;
  gap: var(--kb-gap);
  align-items: start;
}

.page-faq .kb-steps__figure {
  margin: 0;
  position: relative;
}

.page-faq .kb-steps__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border: 1px solid var(--sy-line-strong);
  border-radius: var(--sy-radius);
  background: var(--sy-glass);
  filter: saturate(0.85) contrast(1.05);
}

.page-faq .kb-steps__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-faq .kb-step {
  border: 1px solid var(--sy-line);
  border-left: 2px solid var(--sy-steel);
  background: var(--kb-wash);
  border-radius: var(--sy-radius);
  padding: 16px var(--kb-pad) 14px;
  transition: border-color 0.24s var(--sy-ease), background 0.24s var(--sy-ease);
}

.page-faq .kb-step:hover {
  border-left-color: var(--sy-lime);
  background: var(--kb-wash-strong);
}

.page-faq .kb-step:has(.kb-step__check:checked) {
  border-left-color: var(--sy-lime);
  background: rgba(184, 255, 63, 0.07);
}

.page-faq .kb-step__top {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 8px;
}

.page-faq .kb-step__num {
  font-family: var(--sy-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--sy-lime);
}

.page-faq .kb-step__label {
  font-size: 16px;
  font-weight: 500;
  color: var(--sy-paper);
}

.page-faq .kb-step__text {
  font-size: 14px;
  line-height: 1.78;
  color: var(--sy-on-dark-soft);
  margin: 0 0 12px;
}

.page-faq .kb-step__mark {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-family: var(--sy-mono);
  letter-spacing: 0.04em;
  color: var(--sy-silver);
  cursor: pointer;
  user-select: none;
}

.page-faq .kb-step__check {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.page-faq .kb-step__box {
  width: 14px;
  height: 14px;
  border: 1px solid var(--sy-line-strong);
  border-radius: 2px;
  display: inline-block;
  position: relative;
  transition: border-color 0.2s var(--sy-ease), background 0.2s var(--sy-ease);
}

.page-faq .kb-step__check:checked + .kb-step__box {
  background: var(--sy-lime);
  border-color: var(--sy-lime);
}

.page-faq .kb-step__check:checked + .kb-step__box::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 0.5px;
  width: 4px;
  height: 8px;
  border-right: 2px solid var(--sy-charcoal);
  border-bottom: 2px solid var(--sy-charcoal);
  transform: rotate(40deg);
}

.page-faq .kb-step__check:checked ~ .kb-step__word {
  color: var(--sy-lime);
}

.page-faq .kb-step__check:focus-visible + .kb-step__box {
  outline: 2px solid var(--sy-lime);
  outline-offset: 3px;
}

.page-faq .kb-steps__foot {
  margin: clamp(20px, 3vw, 30px) 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--sy-on-dark-soft);
}

/* ---------- 索引 + 问答主体 ---------- */
.page-faq .kb-hub {
  padding-top: clamp(34px, 5vw, 72px);
}

.page-faq .kb-shell {
  display: grid;
  gap: clamp(22px, 3vw, 40px);
  align-items: start;
}

.page-faq .kb-side {
  min-width: 0;
}

.page-faq .kb-side__inner {
  border: 1px solid var(--sy-line);
  border-radius: var(--sy-radius);
  background: var(--kb-wash);
  padding: 14px;
}

.page-faq .kb-side__label {
  margin: 0 0 12px;
  font-family: var(--sy-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--sy-silver);
}

.page-faq .kb-index {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-faq .kb-index__item {
  flex: 0 0 auto;
}

.page-faq .kb-index__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  white-space: nowrap;
  font-size: 13px;
  color: var(--sy-on-dark-soft);
  text-decoration: none;
  border: 1px solid var(--sy-line);
  border-radius: var(--sy-radius);
  transition: color 0.2s var(--sy-ease), border-color 0.2s var(--sy-ease), background 0.2s var(--sy-ease);
}

.page-faq .kb-index__link:hover,
.page-faq .kb-index__link:focus-visible {
  color: var(--sy-paper);
  border-color: var(--sy-lime);
  background: rgba(184, 255, 63, 0.08);
}

.page-faq .kb-index__link:focus-visible {
  outline: 2px solid var(--sy-lime);
  outline-offset: 2px;
}

.page-faq .kb-index__num {
  font-family: var(--sy-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--sy-lime);
}

.page-faq .kb-side__back {
  display: inline-block;
  margin-top: 14px;
  font-family: var(--sy-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--sy-silver);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--sy-ease), border-color 0.2s var(--sy-ease);
}

.page-faq .kb-side__back:hover,
.page-faq .kb-side__back:focus-visible {
  color: var(--sy-lime);
  border-bottom-color: var(--sy-lime);
}

.page-faq .kb-main {
  min-width: 0;
}

.page-faq .kb-main__head {
  margin-bottom: clamp(16px, 2.4vw, 26px);
}

.page-faq .kb-main__title {
  font-family: var(--sy-display);
  font-weight: 800;
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--sy-paper);
  margin: 0 0 8px;
}

.page-faq .kb-main__hint {
  font-size: 14px;
  line-height: 1.8;
  color: var(--sy-on-dark-soft);
  margin: 0;
}

/* 纯 CSS 分类筛选 */
.page-faq .kb-filter {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  border: 0;
  padding: 0;
  margin: 0 0 clamp(20px, 2.8vw, 32px);
}

.page-faq .kb-filter__legend {
  width: 100%;
  padding: 0;
  margin-bottom: 4px;
  font-family: var(--sy-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--sy-silver);
}

.page-faq .kb-filter__input {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.page-faq .kb-filter__label {
  display: inline-flex;
  align-items: center;
  padding: 7px 15px;
  border: 1px solid var(--sy-line-strong);
  border-radius: 999px;
  font-size: 13px;
  line-height: 1;
  color: var(--sy-on-dark-soft);
  cursor: pointer;
  transition: color 0.2s var(--sy-ease), background 0.2s var(--sy-ease), border-color 0.2s var(--sy-ease);
}

.page-faq .kb-filter__label:hover {
  color: var(--sy-paper);
  border-color: var(--sy-lime);
}

.page-faq .kb-filter__input:checked + .kb-filter__label {
  background: var(--sy-lime);
  border-color: var(--sy-lime);
  color: var(--sy-charcoal);
  font-weight: 500;
}

.page-faq .kb-filter__input:focus-visible + .kb-filter__label {
  outline: 2px solid var(--sy-lime);
  outline-offset: 3px;
}

.page-faq .kb-main:has(#kb-f-setup:checked) .kb-group:not([data-cat="setup"]),
.page-faq .kb-main:has(#kb-f-revisit:checked) .kb-group:not([data-cat="revisit"]),
.page-faq .kb-main:has(#kb-f-subs:checked) .kb-group:not([data-cat="subs"]),
.page-faq .kb-main:has(#kb-f-archive:checked) .kb-group:not([data-cat="archive"]),
.page-faq .kb-main:has(#kb-f-account:checked) .kb-group:not([data-cat="account"]) {
  display: none;
}

/* ---------- 问答组 ---------- */
.page-faq .kb-groups {
  display: grid;
  gap: clamp(26px, 4vw, 46px);
}

.page-faq .kb-group {
  scroll-margin-top: calc(var(--sy-header-h) + 18px);
}

.page-faq .kb-group__head {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding-bottom: 12px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--sy-line);
}

.page-faq .kb-group__num {
  font-family: var(--sy-mono);
  font-size: 26px;
  line-height: 1;
  font-weight: 500;
  letter-spacing: -0.02em;
  color: transparent;
  -webkit-text-stroke: 1px var(--sy-silver);
  flex: 0 0 auto;
}

.page-faq .kb-group__meta {
  min-width: 0;
}

.page-faq .kb-group__title {
  font-family: var(--sy-display);
  font-weight: 800;
  font-size: clamp(19px, 2.4vw, 25px);
  line-height: 1.24;
  color: var(--sy-paper);
  margin: 0 0 6px;
}

.page-faq .kb-group__desc {
  font-size: 13px;
  line-height: 1.7;
  color: var(--sy-on-dark-soft);
  margin: 0;
}

.page-faq .kb-list {
  display: grid;
  gap: 8px;
}

.page-faq .kb-item {
  border: 1px solid var(--sy-line);
  border-radius: var(--sy-radius);
  background: var(--kb-wash);
  transition: border-color 0.24s var(--sy-ease), background 0.24s var(--sy-ease);
}

.page-faq .kb-item:hover {
  border-color: var(--sy-line-strong);
  background: var(--kb-wash-strong);
}

.page-faq .kb-item[open] {
  border-color: rgba(184, 255, 63, 0.42);
  background: var(--kb-wash-strong);
}

.page-faq .kb-item__q {
  display: flex;
  align-items: baseline;
  gap: 12px;
  list-style: none;
  cursor: pointer;
  padding: 14px var(--kb-pad);
  font-size: 15px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--sy-paper);
}

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

.page-faq .kb-item__q::after {
  content: "+";
  margin-left: auto;
  flex: 0 0 auto;
  font-family: var(--sy-mono);
  font-size: 17px;
  line-height: 1;
  color: var(--sy-lime);
}

.page-faq .kb-item[open] .kb-item__q::after {
  content: "−";
}

.page-faq .kb-item__q:focus-visible {
  outline: 2px solid var(--sy-lime);
  outline-offset: -2px;
  border-radius: var(--sy-radius);
}

.page-faq .kb-item__idx {
  flex: 0 0 auto;
  font-family: var(--sy-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--sy-silver);
  border: 1px solid var(--sy-line);
  border-radius: 2px;
  padding: 2px 6px;
}

.page-faq .kb-item__a {
  padding: 12px var(--kb-pad) 16px;
  margin: 0;
  border-top: 1px solid var(--sy-line);
}

.page-faq .kb-item__a p {
  margin: 0;
  font-size: 14px;
  line-height: 1.82;
  color: var(--sy-on-dark-soft);
}

/* ---------- 收尾提示 ---------- */
.page-faq .kb-callout {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: clamp(28px, 4vw, 46px);
  padding: clamp(18px, 2.4vw, 26px) var(--kb-pad);
  border: 1px solid var(--sy-line-strong);
  border-left: 3px solid var(--sy-orange);
  border-radius: var(--sy-radius);
  background:
    linear-gradient(90deg, rgba(255, 90, 31, 0.09), transparent 55%),
    var(--sy-charcoal);
}

.page-faq .kb-callout__text {
  min-width: 0;
}

.page-faq .kb-callout__title {
  margin: 0 0 6px;
  font-family: var(--sy-display);
  font-weight: 800;
  font-size: 18px;
  color: var(--sy-paper);
}

.page-faq .kb-callout__desc {
  margin: 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--sy-on-dark-soft);
}

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

@media (min-width: 900px) {
  .page-faq .kb-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(24px, 4vw, 64px);
    align-items: end;
  }

  .page-faq .kb-steps__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(22px, 3.4vw, 48px);
    align-items: start;
  }

  .page-faq .kb-steps__figure {
    position: sticky;
    top: calc(var(--sy-header-h) + 24px);
  }

  .page-faq .kb-callout {
    flex-wrap: nowrap;
  }
}

@media (min-width: 1024px) {
  .page-faq .kb-shell {
    grid-template-columns: 264px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 64px);
  }

  .page-faq .kb-side__inner {
    position: sticky;
    top: calc(var(--sy-header-h) + 20px);
    padding: 20px;
  }

  .page-faq .kb-index {
    display: block;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-faq .kb-index__item + .kb-index__item {
    margin-top: 2px;
  }

  .page-faq .kb-index__link {
    display: flex;
    width: 100%;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    padding: 9px 10px;
    font-size: 14px;
    white-space: normal;
  }

  .page-faq .kb-index__link:hover,
  .page-faq .kb-index__link:focus-visible {
    border-left-color: var(--sy-lime);
    background: rgba(184, 255, 63, 0.07);
  }

  .page-faq .kb-group__num {
    font-size: 34px;
  }
}

@media (min-width: 1180px) {
  .page-faq .kb-hero__title {
    letter-spacing: -0.024em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-faq .kb-link,
  .page-faq .kb-step,
  .page-faq .kb-item,
  .page-faq .kb-index__link,
  .page-faq .kb-filter__label,
  .page-faq .kb-side__back,
  .page-faq .kb-step__box {
    transition: none;
  }
}