.page-faq {
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
}

/* ---------- 首屏 ---------- */
.page-faq .faq-hero {
  position: relative;
  overflow: hidden;
  padding: 22px 0 44px;
  background:
    radial-gradient(120% 140% at 100% 0%, rgba(228, 0, 43, 0.34) 0%, rgba(228, 0, 43, 0) 58%),
    radial-gradient(90% 120% at 0% 100%, rgba(0, 229, 208, 0.14) 0%, rgba(0, 229, 208, 0) 62%),
    var(--ink-deep);
  border-bottom: 1px solid var(--grid-line);
}

.page-faq .faq-hero::after {
  content: "";
  position: absolute;
  top: -110px;
  right: -110px;
  width: 260px;
  height: 260px;
  background: linear-gradient(135deg, var(--red) 0%, var(--red-deep) 100%);
  opacity: 0.26;
  transform: rotate(24deg);
  pointer-events: none;
}

.page-faq .faq-hero .breadcrumbs {
  position: relative;
  z-index: 1;
}

.page-faq .faq-hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 26px;
  margin-top: 18px;
}

.page-faq .faq-hero-main h1 {
  margin: 12px 0 0;
  font-family: var(--font-head);
  font-size: clamp(30px, 8vw, 58px);
  font-weight: 300;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.page-faq .faq-hero-main .section-lead {
  margin-top: 16px;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--muted);
}

.page-faq .faq-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-faq .faq-hero-side {
  position: relative;
  padding: 18px 18px 18px 22px;
  background: linear-gradient(160deg, var(--ink-raise) 0%, var(--panel) 100%);
  border-left: 2px solid var(--lime);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-faq .faq-side-title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--lime);
  text-transform: uppercase;
}

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

.page-faq .faq-side-list a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 9px 4px;
  color: var(--paper);
  font-size: 15px;
  text-decoration: none;
  border-bottom: 1px solid rgba(42, 42, 56, 0.7);
  transition: color 0.25s var(--ease), padding-left 0.25s var(--ease);
}

.page-faq .faq-side-list a:hover,
.page-faq .faq-side-list a:focus-visible {
  color: var(--cyan);
  padding-left: 10px;
}

.page-faq .faq-side-list .mono {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

/* ---------- 通用章节头 ---------- */
.page-faq .faq-section-head {
  max-width: 44em;
  margin-bottom: 26px;
}

.page-faq .faq-section-head .section-title {
  margin: 10px 0 12px;
}

.page-faq .faq-section-head .section-lead {
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 四步概览 ---------- */
.page-faq .faq-steps-grid {
  display: grid;
  gap: 28px;
}

.page-faq .steps-track {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
}

.page-faq .steps-track::before {
  content: "";
  position: absolute;
  left: 33px;
  top: 30px;
  bottom: 30px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(0, 229, 208, 0.06) 100%);
}

.page-faq .step {
  position: relative;
  padding: 16px 18px 16px 66px;
  background: linear-gradient(160deg, var(--ink-raise) 0%, var(--panel) 100%);
  border: 1px solid var(--grid-line);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease);
}

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

.page-faq .step-num {
  position: absolute;
  left: 14px;
  top: 15px;
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  background: var(--ink);
  border: 1px solid var(--grid-line);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-faq .step-title {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 500;
  line-height: 1.4;
}

.page-faq .step-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--muted);
}

.page-faq .step-result {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  line-height: 1.6;
  color: var(--lime);
}

.page-faq .steps-side figure {
  margin: 0 0 18px;
}

/* ---------- 问题区：左索引 + 右折叠 ---------- */
.page-faq .faq-grid {
  display: grid;
  gap: 26px;
}

.page-faq .faq-rail {
  align-self: start;
  border-left: 1px solid var(--grid-line);
  padding-left: 0;
  overflow-x: auto;
}

.page-faq .faq-rail-title {
  margin: 0 0 10px;
  padding-left: 2px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--muted);
  text-transform: uppercase;
}

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

.page-faq .faq-rail-list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  white-space: nowrap;
  font-size: 14px;
  color: var(--paper);
  text-decoration: none;
  background: var(--ink-raise);
  border: 1px solid var(--grid-line);
  transition: border-color 0.25s var(--ease), color 0.25s var(--ease), background 0.25s var(--ease);
}

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

.page-faq .faq-rail-num {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

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

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

.page-faq .faq-group + .faq-group {
  margin-top: 42px;
}

.page-faq .faq-group-head {
  padding-top: 14px;
  border-top: 2px solid var(--red);
  margin-bottom: 14px;
}

.page-faq .faq-group:target .faq-group-head {
  border-top-color: var(--lime);
}

.page-faq .faq-group-num {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--red);
}

.page-faq .faq-group-head h3 {
  margin: 8px 0 8px;
  font-family: var(--font-head);
  font-size: 24px;
  font-weight: 400;
  letter-spacing: -0.01em;
}

.page-faq .faq-group-head p {
  margin: 0;
  max-width: 44em;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.page-faq .faq-group-figure {
  margin: 0 0 18px;
}

.page-faq .faq-list {
  display: grid;
  gap: 8px;
  margin-top: 16px;
}

.page-faq .faq-item {
  background: var(--ink-raise);
  border: 1px solid var(--grid-line);
  transition: background 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-faq .faq-item:hover {
  border-color: var(--cyan);
}

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

.page-faq .faq-item summary {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
  font-size: 15.5px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--paper);
}

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

.page-faq .faq-q {
  flex: 1 1 auto;
  min-width: 0;
}

.page-faq .faq-plus {
  position: relative;
  flex: 0 0 16px;
  width: 16px;
  height: 16px;
  margin-top: 4px;
  transition: transform 0.3s var(--ease);
}

.page-faq .faq-plus::before,
.page-faq .faq-plus::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: background 0.25s var(--ease);
}

.page-faq .faq-plus::before {
  left: 0;
  top: 7px;
  width: 16px;
  height: 2px;
}

.page-faq .faq-plus::after {
  left: 7px;
  top: 0;
  width: 2px;
  height: 16px;
}

.page-faq .faq-item[open] .faq-plus {
  transform: rotate(45deg);
}

.page-faq .faq-item[open] .faq-plus::before,
.page-faq .faq-item[open] .faq-plus::after {
  background: var(--lime);
}

.page-faq .faq-answer {
  padding: 0 16px 16px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--paper);
}

.page-faq .faq-answer p {
  margin: 0 0 8px;
  max-width: 40em;
}

.page-faq .faq-answer p:last-child {
  margin-bottom: 0;
  color: var(--muted);
}

.page-faq .faq-help-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

/* ---------- 焦点可见性 ---------- */
.page-faq a:focus-visible,
.page-faq summary:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

/* ---------- 桌面栅格 ---------- */
@media (min-width: 900px) {
  .page-faq .faq-hero {
    padding: 30px 0 60px;
  }

  .page-faq .faq-hero-grid {
    grid-template-columns: minmax(0, 1fr) 320px;
    align-items: end;
    gap: 48px;
    margin-top: 26px;
  }

  .page-faq .faq-section-head {
    margin-bottom: 34px;
  }

  .page-faq .faq-steps-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 48px;
    align-items: start;
  }

  .page-faq .faq-grid {
    grid-template-columns: 216px minmax(0, 1fr);
    gap: 52px;
  }

  .page-faq .faq-rail {
    position: sticky;
    top: 96px;
    overflow-x: visible;
    padding-left: 16px;
  }

  .page-faq .faq-rail-title {
    padding-left: 0;
  }

  .page-faq .faq-rail-list {
    flex-direction: column;
    gap: 0;
  }

  .page-faq .faq-rail-list a {
    padding: 10px 10px 10px 0;
    background: transparent;
    border: 0;
    border-bottom: 1px solid var(--grid-line);
    white-space: normal;
    width: 100%;
  }

  .page-faq .faq-rail-list a:hover,
  .page-faq .faq-rail-list a:focus-visible {
    padding-left: 10px;
    background: rgba(0, 229, 208, 0.06);
  }

  .page-faq .faq-item summary {
    padding: 17px 20px;
    font-size: 16px;
  }

  .page-faq .faq-answer {
    padding: 0 20px 20px;
    font-size: 15.5px;
  }

  .page-faq .faq-group-head h3 {
    font-size: 28px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-faq .step,
  .page-faq .faq-item,
  .page-faq .faq-plus,
  .page-faq .faq-side-list a,
  .page-faq .faq-rail-list a {
    transition: none;
  }

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