.page-faq {
  --faq-rail-w: 380px;
  --faq-gap: clamp(22px, 3.4vw, 48px);
  --faq-soft-cyan: rgba(53, 230, 210, 0.12);
  --faq-soft-magenta: rgba(255, 61, 139, 0.16);
  padding-bottom: 80px;
}

.page-faq .page-head {
  padding: 36px 0 0;
  border-bottom: 2px solid var(--line);
}

.page-faq .page-head__top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 16px;
  margin-bottom: 18px;
}

.page-faq .page-head .display-1 {
  max-width: 22ch;
  margin: 0 0 18px;
}

.page-faq .page-head .lede {
  max-width: 62ch;
  margin: 0 0 30px;
  color: var(--muted);
}

/* ---- 首屏四格入口 ---- */
.page-faq .faq-jump {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  padding-bottom: 34px;
}

.page-faq .jump-card {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-rows: auto auto;
  gap: 4px 12px;
  align-items: baseline;
  padding: 16px 18px;
  border: 2px solid var(--line);
  background: var(--mid);
  color: var(--ink);
  text-decoration: none;
  box-shadow: var(--shadow-card);
  transition: transform 180ms var(--ease), border-color 180ms var(--ease),
    box-shadow 180ms var(--ease), background-color 180ms var(--ease);
}

.page-faq .jump-card__num {
  grid-row: 1 / span 2;
  align-self: start;
  font-size: 22px;
  line-height: 1;
  color: var(--cyan);
}

.page-faq .jump-card__t {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.page-faq .jump-card__d {
  font-size: 13px;
  color: var(--muted);
}

.page-faq .jump-card:hover,
.page-faq .jump-card:focus-visible {
  transform: translateY(-4px);
  border-color: var(--cyan);
  background: var(--bg-deep);
  box-shadow: var(--shadow-card-hover);
}

.page-faq .jump-card:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* ---- 主体两栏 ---- */
.page-faq .faq-shell {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--faq-gap);
  margin-top: 38px;
}

.page-faq .tier-rail__inner {
  border: 2px solid var(--line);
  background: var(--bg-deep);
  padding: 18px 16px 22px;
  box-shadow: var(--shadow-card);
}

.page-faq .tier-rail__figure {
  margin: 0 0 18px;
}

.page-faq .tier-rail__figure img,
.page-faq .qa-banner img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-faq .tier-rail h2 {
  margin: 0 0 10px;
}

.page-faq .tier-rail__note {
  margin: 0 0 18px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.page-faq .tier-table {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
  counter-reset: none;
}

.page-faq .tier-row {
  border: 2px solid var(--line);
  border-left: 6px solid var(--cyan);
  background: var(--mid);
  transition: border-color 180ms var(--ease), background-color 180ms var(--ease);
}

.page-faq .tier-row > summary {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 4px 10px;
  align-items: baseline;
  padding: 11px 12px;
  cursor: pointer;
  list-style: none;
}

.page-faq .tier-row > summary::-webkit-details-marker {
  display: none;
}

.page-faq .tier-row__num {
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.08em;
  transition: color 180ms var(--ease);
}

.page-faq .tier-row__name {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.page-faq .tier-row__code {
  font-size: 12px;
  color: var(--amber);
  letter-spacing: 0.1em;
}

.page-faq .tier-row__hint {
  grid-column: 1 / -1;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

.page-faq .tier-row > summary:hover {
  background: var(--faq-soft-cyan);
}

.page-faq .tier-row > summary:hover .tier-row__num,
.page-faq .tier-row > summary:hover .tier-row__name {
  color: var(--cyan);
}

.page-faq .tier-row > summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-faq .tier-row[open] {
  border-color: var(--cyan);
  background: var(--bg);
}

.page-faq .tier-row__body {
  margin: 0;
  padding: 10px 12px 13px;
  border-top: 1px dashed var(--line);
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
}

.page-faq .tier-row--bridge {
  border-left-color: var(--magenta);
  background: linear-gradient(90deg, var(--faq-soft-magenta), var(--mid) 65%);
}

.page-faq .tier-row--bridge .tier-row__num,
.page-faq .tier-row--bridge .tier-row__code {
  color: var(--magenta);
}

.page-faq .tier-row--bridge > summary:hover {
  background: rgba(255, 61, 139, 0.14);
}

.page-faq .tier-row--bridge > summary:hover .tier-row__name {
  color: var(--magenta);
}

.page-faq .tier-rail__foot {
  margin: 18px 0 0;
  padding-top: 14px;
  border-top: 2px solid var(--line);
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---- 问答流 ---- */
.page-faq .qa-banner {
  margin: 0 0 34px;
  border: 2px solid var(--line);
}

.page-faq .qa-group {
  margin-bottom: 44px;
  scroll-margin-top: 100px;
}

.page-faq .qa-group__head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--line);
}

.page-faq .qa-group__head h2 {
  position: relative;
  margin: 0;
  padding-bottom: 10px;
}

.page-faq .qa-group__head h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 48px;
  height: 2px;
  background: var(--cyan);
}

.page-faq .qa-group__count {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--muted);
  white-space: nowrap;
}

.page-faq .qa-group__lede {
  margin: 16px 0 20px;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-faq .qa-group__list {
  display: grid;
  gap: 10px;
}

.page-faq .qa-item {
  border: 2px solid var(--line);
  background: var(--bg-deep);
  transition: border-color 180ms var(--ease);
}

.page-faq .qa-item > summary {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 12px;
  align-items: baseline;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-faq .qa-item__num {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--muted);
  transition: color 180ms var(--ease);
}

.page-faq .qa-item__q {
  font-size: 16px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--ink);
}

.page-faq .qa-item__mark {
  align-self: center;
  font-size: 14px;
  color: var(--cyan);
}

.page-faq .qa-item__mark::before {
  content: "＋";
}

.page-faq .qa-item[open] .qa-item__mark::before {
  content: "－";
}

.page-faq .qa-item > summary:hover {
  background: var(--faq-soft-cyan);
}

.page-faq .qa-item > summary:hover .qa-item__num {
  color: var(--cyan);
}

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

.page-faq .qa-item[open] {
  border-color: var(--cyan);
}

.page-faq .qa-item__body {
  padding: 0 16px 16px;
  border-top: 1px dashed var(--line);
}

.page-faq .qa-item__body p {
  margin: 14px 0 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

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

.page-faq .qa-item__body a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* ---- 协助区 ---- */
.page-faq .qa-group--help .qa-group__head h2::after {
  background: var(--amber);
}

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

.page-faq .help-card {
  display: grid;
  gap: 6px;
  padding: 16px;
  border: 2px solid var(--line);
  border-top: 4px solid var(--amber);
  background: var(--mid);
}

.page-faq .help-card__label {
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--amber);
}

.page-faq .help-card__value {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--ink);
  word-break: break-word;
}

.page-faq .help-card__note {
  font-size: 13px;
  line-height: 1.65;
  color: var(--muted);
}

.page-faq .help-tips {
  margin-top: 28px;
  padding: 20px 18px;
  border: 2px dashed var(--line);
  background: var(--bg-deep);
}

.page-faq .help-tips h3 {
  margin: 0 0 14px;
}

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

.page-faq .help-steps li {
  position: relative;
  padding-left: 46px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
  counter-increment: helpstep;
}

.page-faq .help-steps {
  counter-reset: helpstep;
}

.page-faq .help-steps li::before {
  content: "0" counter(helpstep);
  position: absolute;
  left: 0;
  top: 1px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
  border: 1px solid var(--line);
  padding: 2px 6px;
}

.page-faq .help-foot {
  margin: 24px 0 0;
  max-width: 62ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
}

.page-faq .help-foot a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-faq .help-foot a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

/* ---- 返回段位表 ---- */
.page-faq .tier-back {
  display: none;
}

/* ---- 窄屏 ---- */
@media (max-width: 599px) {
  .page-faq .tier-row > summary,
  .page-faq .qa-item > summary {
    grid-template-columns: auto 1fr;
  }

  .page-faq .qa-item__mark {
    display: none;
  }

  .page-faq .tier-row__code {
    grid-column: 2;
  }

  .page-faq .page-head .display-1 {
    font-size: clamp(28px, 8vw, 40px);
  }
}

@media (min-width: 640px) {
  .page-faq .faq-jump {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 1000px) {
  .page-faq .faq-jump {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-faq .faq-shell {
    grid-template-columns: var(--faq-rail-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-faq .tier-rail__inner {
    position: sticky;
    top: 96px;
    max-height: calc(100vh - 128px);
    overflow-y: auto;
    padding-right: 14px;
    scrollbar-width: thin;
    scrollbar-color: var(--line) transparent;
  }

  .page-faq .tier-rail {
    align-self: start;
  }

  .page-faq .tier-back {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    position: fixed;
    right: 26px;
    bottom: 96px;
    z-index: 6;
    padding: 10px 14px;
    border: 2px solid var(--line);
    background: var(--bg-deep);
    color: var(--muted);
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.1em;
    text-decoration: none;
    transition: border-color 180ms var(--ease), color 180ms var(--ease),
      transform 180ms var(--ease);
  }

  .page-faq .tier-back::before {
    content: "▲";
    font-size: 10px;
    color: var(--cyan);
  }

  .page-faq .tier-back:hover,
  .page-faq .tier-back:focus-visible {
    border-color: var(--cyan);
    color: var(--ink);
    transform: translateY(-4px);
  }

  .page-faq .tier-back:focus-visible {
    outline: 2px solid var(--cyan);
    outline-offset: 2px;
  }
}
<<<END>>>