.page-faq {
  --faq-axis-w: 17.5rem;
  --faq-col-gap: clamp(24px, 4vw, 56px);
  --faq-panel: rgba(28, 51, 80, 0.52);
  --faq-panel-open: rgba(28, 51, 80, 0.72);
}

/* ---------- 首屏 ---------- */
.page-faq .faq-hero {
  position: relative;
  padding-block: clamp(26px, 4.6vw, 56px) clamp(28px, 4.2vw, 50px);
  border-bottom: 1px solid var(--line-soft);
  overflow: hidden;
}

.page-faq .faq-hero::before {
  content: "";
  position: absolute;
  inset: -30% -10% auto -10%;
  height: 180%;
  pointer-events: none;
  background:
    radial-gradient(60% 70% at 10% 6%, rgba(61, 245, 212, 0.11), transparent 62%),
    radial-gradient(48% 62% at 94% 12%, rgba(91, 140, 255, 0.11), transparent 66%);
}

.page-faq .faq-hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 0;
  max-width: 940px;
}

.page-faq .faq-hero h1 {
  margin: 14px 0 0;
  max-width: 20ch;
}

.page-faq .faq-hero .lede {
  margin-top: 18px;
  max-width: 68ch;
}

.page-faq .faq-hero .btn-row {
  margin-top: 26px;
}

/* ---------- 数据条 ---------- */
.page-faq .faq-strip {
  border-bottom: 1px solid var(--line-soft);
  background: var(--surface-deep);
}

.page-faq .faq-strip-inner {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 14px;
  padding-block: 20px;
}

@media (min-width: 720px) {
  .page-faq .faq-strip-inner {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-faq .faq-stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-left: 13px;
  border-left: 2px solid rgba(61, 245, 212, 0.42);
}

.page-faq .faq-stat .data-num {
  line-height: 1.05;
}

.page-faq .faq-stat .data-unit {
  font-size: 13px;
  color: var(--gray);
  letter-spacing: 0.02em;
}

/* ---------- 分屏布局 ---------- */
.page-faq .faq-layout {
  display: grid;
  gap: clamp(26px, 4vw, 44px);
  padding-block: clamp(30px, 4.6vw, 60px) clamp(46px, 6vw, 84px);
  align-items: start;
}

@media (min-width: 960px) {
  .page-faq .faq-layout {
    grid-template-columns: var(--faq-axis-w) minmax(0, 1fr);
    gap: var(--faq-col-gap);
  }
}

/* ---------- 左侧索引轴 ---------- */
.page-faq .faq-axis {
  display: grid;
  gap: 14px;
  align-content: start;
}

@media (min-width: 960px) {
  .page-faq .faq-axis {
    position: sticky;
    top: calc(var(--header-h) + 22px);
    max-height: calc(100vh - var(--header-h) - 46px);
    overflow-y: auto;
    padding-right: 4px;
    scrollbar-width: thin;
  }
}

.page-faq .faq-axis-label {
  margin: 0;
  font-family: var(--font-head);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gray);
}

.page-faq .faq-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 960px) {
  .page-faq .faq-nav {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 3px;
  }
}

.page-faq .faq-nav-link {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  border: 1px solid var(--line-soft);
  border-radius: var(--pill);
  background: var(--faq-panel);
  color: var(--mist);
  font-family: var(--font-head);
  font-size: 13.5px;
  font-weight: 500;
  line-height: 1.4;
  text-decoration: none;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease), background 0.25s var(--ease);
}

@media (min-width: 960px) {
  .page-faq .faq-nav-link {
    border-radius: var(--radius-sm);
    border-color: transparent;
    border-left: 2px solid transparent;
    background: transparent;
    padding: 11px 12px;
  }
}

.page-faq .faq-nav-num {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--gray);
  letter-spacing: 0.05em;
}

.page-faq .faq-nav-link:hover,
.page-faq .faq-nav-link:focus-visible {
  color: var(--teal);
  border-color: var(--line-strong);
  background: rgba(61, 245, 212, 0.07);
}

.page-faq .faq-nav-link[data-active="true"] {
  color: var(--teal);
  border-color: var(--line-strong);
  background: rgba(61, 245, 212, 0.09);
}

@media (min-width: 960px) {
  .page-faq .faq-nav-link[data-active="true"] {
    border-left-color: var(--teal);
    background: rgba(61, 245, 212, 0.07);
  }
}

.page-faq .faq-axis-note {
  margin: 4px 0 0;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  border-left: 2px solid rgba(245, 193, 92, 0.5);
  background: rgba(14, 59, 58, 0.4);
  color: var(--gray);
  font-size: 13px;
  line-height: 1.75;
}

/* ---------- 章节 ---------- */
.page-faq .faq-section {
  scroll-margin-top: calc(var(--header-h) + 26px);
}

.page-faq .faq-section + .faq-section {
  margin-top: clamp(38px, 5vw, 68px);
}

.page-faq .faq-section-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 14px;
  align-items: start;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line-soft);
}

.page-faq .faq-icon {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 12px;
  border: 1px solid var(--line-soft);
  background: var(--faq-panel);
  color: var(--teal);
  flex: none;
}

.page-faq .faq-icon svg {
  width: 20px;
  height: 20px;
}

.page-faq .faq-icon--account { color: var(--teal); }
.page-faq .faq-icon--devices { color: var(--volt); }
.page-faq .faq-icon--ios { color: var(--teal); }
.page-faq .faq-icon--changelog { color: var(--brick); }
.page-faq .faq-icon--erratum { color: var(--gold); }
.page-faq .faq-icon--support { color: var(--teal); }

.page-faq .faq-section-head .section-title {
  margin: 6px 0 0;
}

.page-faq .faq-section-sub {
  grid-column: 2;
  margin: 6px 0 0;
  color: var(--gray);
  font-size: 14.5px;
  line-height: 1.78;
  max-width: 64ch;
}

/* ---------- 问答条目 ---------- */
.page-faq .faq-list {
  display: grid;
  gap: 9px;
  margin-top: 20px;
}

.page-faq .faq-item {
  position: relative;
  border: 1px solid var(--line-soft);
  border-left: 3px solid transparent;
  border-radius: var(--radius);
  background: var(--faq-panel);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  overflow: hidden;
  scroll-margin-top: calc(var(--header-h) + 26px);
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease);
}

.page-faq .faq-item:hover {
  border-color: var(--line-soft);
  border-left-color: rgba(61, 245, 212, 0.5);
}

.page-faq .faq-item[open] {
  border-color: var(--line-soft);
  border-left-color: var(--teal);
  background: var(--faq-panel-open);
}

.page-faq .faq-q {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr) 18px;
  gap: 10px;
  align-items: center;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-size: 15.5px;
  font-weight: 600;
  line-height: 1.55;
  color: var(--mist);
  transition: color 0.25s var(--ease);
}

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

.page-faq .faq-item[open] .faq-q {
  color: var(--teal);
}

.page-faq .faq-q-num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  color: var(--gray);
  letter-spacing: 0.05em;
}

.page-faq .faq-q-mark {
  position: relative;
  width: 16px;
  height: 16px;
  justify-self: end;
}

.page-faq .faq-q-mark::before,
.page-faq .faq-q-mark::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1.6px;
  border-radius: 2px;
  background: var(--teal);
  transform: translateY(-50%);
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}

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

.page-faq .faq-item[open] .faq-q-mark::after {
  transform: translateY(-50%) rotate(0deg);
  opacity: 0;
}

.page-faq .faq-a {
  padding: 0 18px 20px;
  border-top: 1px solid var(--line-soft);
  padding-top: 16px;
}

.page-faq .faq-item[open] .faq-a {
  animation: faq-unfold 0.34s var(--ease) both;
}

@keyframes faq-unfold {
  from {
    opacity: 0;
    transform: translateY(-5px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.page-faq .faq-a p {
  margin: 0 0 11px;
  font-family: var(--font-body);
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--mist);
}

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

.page-faq .faq-a strong {
  color: var(--gold);
  font-weight: 600;
  font-family: var(--font-mono);
  font-size: 0.96em;
  letter-spacing: 0.01em;
}

/* ---------- 章节配图 ---------- */
.page-faq .faq-media {
  margin: 22px 0 0;
}

/* ---------- 结尾引导 ---------- */
.page-faq .faq-outro {
  margin-top: clamp(42px, 5.4vw, 76px);
}

.page-faq .faq-outro-panel {
  display: grid;
  gap: 22px;
  padding: clamp(22px, 3.2vw, 34px);
  border-radius: var(--radius-lg);
}

@media (min-width: 820px) {
  .page-faq .faq-outro-panel {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 34px;
  }
}

.page-faq .faq-outro-text .section-title {
  margin: 0 0 10px;
}

.page-faq .faq-outro-text p {
  margin: 0;
  font-family: var(--font-body);
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--gray);
  max-width: 62ch;
}

.page-faq .faq-outro .btn-row {
  margin: 0;
}

/* ---------- 窄屏收紧 ---------- */
@media (max-width: 520px) {
  .page-faq .faq-q {
    grid-template-columns: 24px minmax(0, 1fr) 16px;
    gap: 8px;
    padding: 14px 14px;
    font-size: 15px;
  }

  .page-faq .faq-a {
    padding: 14px 14px 18px;
  }

  .page-faq .faq-section-head {
    gap: 4px 10px;
  }

  .page-faq .faq-icon {
    width: 36px;
    height: 36px;
  }

  .page-faq .faq-axis-note {
    font-size: 12.5px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-faq .faq-item[open] .faq-a {
    animation: none;
  }

  .page-faq .faq-nav-link,
  .page-faq .faq-item,
  .page-faq .faq-q,
  .page-faq .faq-q-mark::before,
  .page-faq .faq-q-mark::after {
    transition: none;
  }
}