.page-faq {
  --faq-gap: clamp(28px, 5vw, 64px);
  --faq-panel: rgba(18, 70, 58, 0.34);
  --faq-tint: rgba(41, 242, 200, 0.07);
  display: block;
}

/* ---------- 首屏 ---------- */
.page-faq .faq-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding-block: clamp(24px, 5vw, 56px) clamp(40px, 7vw, 92px);
  background:
    radial-gradient(115% 90% at 86% -12%, rgba(41, 242, 200, 0.16) 0%, rgba(41, 242, 200, 0) 58%),
    linear-gradient(168deg, var(--deep) 0%, var(--ink) 68%);
  border-bottom: 1px solid var(--line);
}

.page-faq .faq-hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  left: 32%;
  right: -20%;
  bottom: -70px;
  height: 220px;
  transform: rotate(-7deg);
  background: linear-gradient(90deg, rgba(76, 211, 255, 0.12), rgba(255, 106, 43, 0.08) 70%, rgba(255, 194, 75, 0));
  pointer-events: none;
}

.page-faq .faq-hero-inner {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

.page-faq .faq-hero-inner > .breadcrumbs {
  grid-column: 1 / -1;
}

.page-faq .breadcrumbs a {
  color: var(--silver);
  text-decoration: none;
}

.page-faq .breadcrumbs a:hover {
  color: var(--neon);
}

.page-faq .faq-display {
  margin: 14px 0 0;
  font-size: clamp(38px, 8vw, 84px);
  font-weight: 200;
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-faq .faq-hero-copy .lede {
  margin-top: 18px;
  max-width: 46ch;
  color: var(--mist);
}

.page-faq .faq-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-faq .faq-actions .btn {
  text-decoration: none;
}

.page-faq .faq-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px clamp(14px, 3vw, 28px);
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: clamp(16px, 2.6vw, 22px) 0 0;
  border-top: 1px solid var(--line);
}

.page-faq .faq-fact dt {
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--silver);
}

.page-faq .faq-fact dd {
  margin: 6px 0 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
  color: var(--white);
}

.page-faq .faq-fact-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 4vw, 38px);
  line-height: 1;
  color: var(--neon);
}

.page-faq .faq-fact-unit {
  font-size: 13px;
  color: var(--silver);
}

.page-faq .faq-hero-media {
  margin: 0;
  width: 100%;
  border: 1px solid var(--line-strong);
  border-radius: var(--r-m);
  overflow: hidden;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.45);
}

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

.page-faq .faq-hero-media .media-caption {
  font-size: 12px;
}

/* ---------- 主体两栏 ---------- */
.page-faq .faq-main {
  padding-block: clamp(40px, 7vw, 96px);
}

.page-faq .faq-body {
  display: grid;
  gap: clamp(28px, 5vw, 56px);
}

.page-faq .faq-stream {
  min-width: 0;
}

/* ---------- 左侧分类索引 ---------- */
.page-faq .faq-index {
  padding: clamp(18px, 3vw, 26px);
  border: 1px solid var(--line);
  border-radius: var(--r-m);
  background: linear-gradient(180deg, var(--faq-panel), rgba(11, 15, 14, 0.15));
}

.page-faq .faq-index-list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-faq .faq-index-link {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 10px;
  padding: 11px 8px 11px 14px;
  border-left: 2px solid transparent;
  color: var(--mist);
  font-size: 14px;
  text-decoration: none;
  transition: color 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.page-faq .faq-index-link:hover {
  color: var(--white);
  background: var(--faq-tint);
}

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

.page-faq .faq-index-link.is-active,
.page-faq .faq-index-link[data-active] {
  color: var(--neon);
  border-left-color: var(--neon);
  background: rgba(41, 242, 200, 0.09);
}

.page-faq .faq-index-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--silver);
}

.page-faq .faq-index-link.is-active .faq-index-num,
.page-faq .faq-index-link[data-active] .faq-index-num {
  color: var(--neon);
}

.page-faq .faq-index-count {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--silver);
}

.page-faq .faq-index-note {
  margin: 18px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  line-height: 1.6;
  color: var(--silver);
}

/* ---------- 问答组 ---------- */
.page-faq .faq-group + .faq-group {
  margin-top: clamp(44px, 7vw, 82px);
}

.page-faq .faq-group-head {
  display: grid;
  gap: 8px;
  margin-bottom: clamp(16px, 2.6vw, 24px);
}

.page-faq .faq-group-head h2 {
  margin: 0;
  color: var(--white);
}

.page-faq .qa {
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(18, 70, 58, 0.16), rgba(18, 70, 58, 0));
}

.page-faq .qa:last-of-type {
  border-bottom: 1px solid var(--line);
}

.page-faq .qa summary {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 16px;
  padding: clamp(16px, 2.4vw, 22px) clamp(6px, 2vw, 18px);
  list-style: none;
  cursor: pointer;
  color: var(--white);
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.5;
  transition: color 0.2s ease;
}

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

.page-faq .qa summary:hover {
  color: var(--neon);
}

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

.page-faq .qa-toggle {
  position: relative;
  width: 18px;
  height: 18px;
  flex: none;
}

.page-faq .qa-toggle::before,
.page-faq .qa-toggle::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 13px;
  height: 2px;
  border-radius: 2px;
  background: var(--neon);
  transform: translate(-50%, -50%);
  transition: opacity 0.22s ease, transform 0.22s ease;
}

.page-faq .qa-toggle::after {
  transform: translate(-50%, -50%) rotate(90deg);
}

.page-faq .qa[open] .qa-toggle::after {
  opacity: 0;
  transform: translate(-50%, -50%) rotate(0deg);
}

.page-faq .qa-a {
  position: relative;
  margin: 0;
  padding: 2px clamp(6px, 2vw, 18px) clamp(20px, 3vw, 30px) clamp(20px, 3.4vw, 34px);
  color: var(--mist);
  font-size: 15.5px;
  line-height: 1.75;
}

.page-faq .qa-a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  bottom: clamp(20px, 3vw, 30px);
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--neon), rgba(41, 242, 200, 0));
}

.page-faq .qa-a p {
  margin: 0;
}

.page-faq .qa-a p + p {
  margin-top: 12px;
}

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

.page-faq .qa-a a:hover {
  color: var(--neon);
}

.page-faq .qa[open] .qa-a {
  animation: faq-reveal 0.28s ease-out both;
}

@keyframes faq-reveal {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

/* ---------- 技术统计示意图 ---------- */
.page-faq .faq-stats-visual {
  display: grid;
  gap: clamp(18px, 3vw, 28px);
  margin-top: clamp(22px, 3.4vw, 34px);
  padding: clamp(16px, 2.6vw, 24px);
  border: 1px solid var(--line);
  border-radius: var(--r-m);
  background: linear-gradient(200deg, rgba(76, 211, 255, 0.08), rgba(18, 70, 58, 0.28) 55%, rgba(11, 15, 14, 0.2));
}

.page-faq .faq-stats-media {
  margin: 0;
  border-radius: var(--r-s);
  overflow: hidden;
}

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

.page-faq .faq-stats-media .media-caption {
  font-size: 12px;
}

.page-faq .faq-legend {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

.page-faq .faq-legend li {
  padding-left: 14px;
  border-left: 2px solid rgba(255, 194, 75, 0.5);
}

.page-faq .faq-legend-key {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--amber);
}

/* ---------- 底部联系 ---------- */
.page-faq .faq-cta {
  display: grid;
  gap: clamp(18px, 3vw, 32px);
  margin-top: clamp(44px, 7vw, 84px);
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--line-strong);
  border-radius: var(--r-l);
  background:
    radial-gradient(90% 120% at 100% 0%, rgba(255, 106, 43, 0.14), rgba(255, 106, 43, 0) 62%),
    linear-gradient(150deg, var(--board), var(--ink) 78%);
}

.page-faq .faq-cta-copy h2 {
  margin: 10px 0 0;
  color: var(--white);
}

.page-faq .faq-cta-copy p {
  margin: 14px 0 0;
  max-width: 52ch;
  color: var(--mist);
  font-size: 15.5px;
  line-height: 1.75;
}

.page-faq .faq-cta-contact {
  display: grid;
  gap: 8px;
  align-content: start;
  padding-top: clamp(16px, 3vw, 24px);
  border-top: 1px solid var(--line);
}

.page-faq .faq-mail-label {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--silver);
}

.page-faq .faq-mail {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(15px, 2vw, 19px);
  color: var(--neon);
  word-break: break-all;
}

.page-faq .faq-cta-contact .btn {
  justify-self: start;
  margin-top: 8px;
  text-decoration: none;
}

/* ---------- 桌面布局 ---------- */
@media (min-width: 760px) {
  .page-faq .faq-stats-visual {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: center;
  }

  .page-faq .faq-cta {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: end;
  }

  .page-faq .faq-cta-contact {
    border-top: none;
    border-left: 1px solid var(--line);
    padding-top: 0;
    padding-left: clamp(18px, 3vw, 32px);
  }
}

@media (min-width: 900px) {
  .page-faq .faq-hero-inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
    column-gap: clamp(32px, 5vw, 76px);
  }

  .page-faq .faq-hero-media {
    align-self: end;
  }

  .page-faq .faq-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 980px) {
  .page-faq .faq-body {
    grid-template-columns: minmax(200px, 252px) minmax(0, 1fr);
    align-items: start;
    column-gap: var(--faq-gap);
  }

  .page-faq .faq-index {
    position: sticky;
    top: calc(var(--header-offset) + 24px);
  }
}

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

  .page-faq .qa-toggle::before,
  .page-faq .qa-toggle::after,
  .page-faq .faq-index-link {
    transition: none;
  }
}