.page-faq {
  --faq-rail: 224px;
  --faq-hairline: rgba(18, 20, 23, 0.16);
  --faq-hairline-soft: rgba(18, 20, 23, 0.09);
}

/* ---------- 面包屑 ---------- */
.page-faq .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--steel);
}

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

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

.page-faq .breadcrumb span[aria-current="page"] {
  color: var(--mist);
}

/* ---------- 首屏 ---------- */
.page-faq .faq-hero {
  position: relative;
  overflow: hidden;
}

.page-faq .faq-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(215, 222, 217, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(215, 222, 217, 0.05) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(120% 90% at 20% 0%, #000 0%, transparent 72%);
  -webkit-mask-image: radial-gradient(120% 90% at 20% 0%, #000 0%, transparent 72%);
  pointer-events: none;
}

.page-faq .faq-hero .wrap {
  position: relative;
}

.page-faq .faq-hero-grid {
  display: grid;
  gap: 32px;
  margin-top: 26px;
}

.page-faq .faq-hero-copy h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 7vw, 58px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--paper);
}

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

.page-faq .faq-hero-figure {
  margin: 0;
  border: 1px solid var(--line-strong);
}

.page-faq .faq-hero-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.page-faq .chip {
  display: inline-flex;
  align-items: center;
  padding: 9px 14px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  font-size: 13px;
  line-height: 1;
  color: var(--mist);
  text-decoration: none;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}

.page-faq .chip:hover,
.page-faq .chip:focus-visible {
  border-color: var(--lime);
  color: var(--lime);
  background-color: rgba(198, 255, 61, 0.06);
}

/* ---------- 浅色阅读区通用 ---------- */
.page-faq .section--paper {
  color: var(--carbon);
}

.page-faq .section--paper .section-title {
  color: var(--ink-deep);
}

.page-faq .section--paper .lede {
  color: rgba(18, 20, 23, 0.74);
}

/* ---------- 导航四步 ---------- */
.page-faq .faq-rules-head .lede {
  max-width: 62ch;
  margin-top: 16px;
}

.page-faq .steps {
  display: grid;
  gap: 0;
  margin: 44px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--faq-hairline);
}

.page-faq .step {
  padding: 24px 0 26px;
  border-bottom: 1px solid var(--faq-hairline);
  transition: transform 0.32s var(--ease);
}

.page-faq .step-index {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-faq .step-title {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink-deep);
}

.page-faq .step-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(18, 20, 23, 0.72);
}

.page-faq .faq-rules-figure {
  margin: 46px 0 0;
  border: 1px solid var(--faq-hairline);
}

.page-faq .faq-rules-note {
  margin: 26px 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--orange);
  font-size: 14px;
  line-height: 1.8;
  color: rgba(18, 20, 23, 0.7);
}

/* ---------- 层级与术语 ---------- */
.page-faq .faq-levels-grid {
  display: grid;
  gap: 36px;
}

.page-faq .faq-levels-copy .section-title {
  margin-top: 12px;
  color: var(--paper);
}

.page-faq .faq-levels-text {
  margin: 16px 0 0;
  max-width: 48ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

.page-faq .level-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-faq .level-chip {
  padding: 7px 11px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  color: var(--mist);
}

.page-faq .level-chip:nth-child(-n + 3) {
  border-color: rgba(198, 255, 61, 0.45);
  color: var(--lime);
}

.page-faq .level-map {
  padding: 22px 18px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: rgba(18, 20, 23, 0.36);
}

.page-faq .level-graph {
  display: block;
  width: 100%;
  height: auto;
}

.page-faq .level-graph text {
  font-family: var(--font-mono);
  font-size: 13px;
  fill: var(--mist);
}

.page-faq .level-graph .lg-box {
  fill: rgba(242, 240, 230, 0.04);
  stroke: rgba(215, 222, 217, 0.3);
  stroke-width: 1;
}

.page-faq .level-graph .lg-box--top {
  fill: rgba(198, 255, 61, 0.08);
  stroke: var(--lime);
}

.page-faq .level-graph .lg-line {
  fill: none;
  stroke: rgba(215, 222, 217, 0.24);
  stroke-width: 1;
}

.page-faq .level-map-note {
  margin: 16px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--steel);
}

.page-faq .glossary {
  margin: 48px 0 0;
  padding-top: 30px;
  border-top: 1px solid var(--line);
}

.page-faq .term {
  padding: 16px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-faq .term dt {
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--lime);
}

.page-faq .term dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 问答区 ---------- */
.page-faq .qa-layout {
  display: grid;
  gap: 34px;
}

.page-faq .qa-rail-title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: rgba(18, 20, 23, 0.5);
}

.page-faq .qa-rail-list {
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--faq-hairline);
}

.page-faq .qa-rail-list a {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  padding: 11px 0;
  border-bottom: 1px solid var(--faq-hairline);
  font-size: 14px;
  color: rgba(18, 20, 23, 0.78);
  text-decoration: none;
  transition: color 0.18s var(--ease);
}

.page-faq .qa-rail-list a:hover,
.page-faq .qa-rail-list a:focus-visible {
  color: var(--wine);
}

.page-faq .qa-rail-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: rgba(18, 20, 23, 0.4);
}

.page-faq .qa-rail-hint {
  margin: 18px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(18, 20, 23, 0.62);
}

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

.page-faq .qa-main-head .section-title {
  margin: 10px 0 0;
}

.page-faq .qa-group {
  margin-top: 40px;
}

.page-faq .qa-group-title {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink-deep);
}

.page-faq .qa-group-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--wine);
}

.page-faq .qa-item {
  border-bottom: 1px solid var(--faq-hairline);
}

.page-faq .qa-item summary {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 18px 0;
  list-style: none;
  cursor: pointer;
  font-size: 15px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--carbon);
  transition: color 0.18s var(--ease);
}

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

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

.page-faq .qa-item summary:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

.page-faq .qa-item summary::after {
  content: "+";
  margin-left: auto;
  flex: none;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--wine);
}

.page-faq .qa-item[open] summary::after {
  content: "–";
}

.page-faq .qa-item-num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: rgba(18, 20, 23, 0.42);
}

.page-faq .qa-answer {
  padding: 0 0 20px 38px;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(18, 20, 23, 0.74);
}

.page-faq .qa-answer p {
  margin: 0 0 10px;
}

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

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

.page-faq .qa-tail {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 16px;
  margin-top: 48px;
  padding: 24px;
  border: 1px solid var(--faq-hairline);
  border-left: 2px solid var(--orange);
  background-color: rgba(18, 20, 23, 0.03);
}

.page-faq .qa-tail p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(18, 20, 23, 0.74);
}

.page-faq .qa-tail a:not(.btn) {
  color: var(--wine);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-faq .steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    border-bottom: 1px solid var(--faq-hairline);
  }

  .page-faq .step {
    padding: 26px 22px 30px;
    border-bottom: 0;
    border-left: 1px solid var(--faq-hairline);
  }

  .page-faq .step:first-child {
    padding-left: 0;
    border-left: 0;
  }

  .page-faq .step:hover {
    transform: translateY(-2px);
  }

  .page-faq .glossary {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 48px;
  }

  .page-faq .qa-tail {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

@media (min-width: 900px) {
  .page-faq .faq-hero-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 56px;
    align-items: end;
    margin-top: 34px;
  }

  .page-faq .faq-levels-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.92fr);
    gap: 64px;
    align-items: start;
  }
}

@media (min-width: 960px) {
  .page-faq .qa-layout {
    grid-template-columns: var(--faq-rail) minmax(0, 1fr);
    gap: 64px;
    align-items: start;
  }

  .page-faq .qa-rail-sticky {
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-faq .step,
  .page-faq .chip,
  .page-faq .qa-item summary,
  .page-faq .qa-rail-list a {
    transition-duration: 0.01ms;
  }

  .page-faq .step:hover {
    transform: none;
  }
}