.page-about {
  color: var(--ink-deep);
  padding-bottom: 64px;
  background-image:
    linear-gradient(to right, rgba(213, 221, 214, .45) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(213, 221, 214, .35) 1px, transparent 1px);
  background-size: 96px 96px;
  background-position: -1px -1px;
}

.page-about .crumbs {
  padding-top: 18px;
}

/* ---------- 首屏 ---------- */
.page-about .about-mast {
  padding-top: 18px;
  padding-bottom: 30px;
  border-bottom: 1px solid var(--hair);
  margin-bottom: 26px;
}

.page-about .about-mast .eyebrow {
  display: inline-block;
  font-size: var(--t-1);
  letter-spacing: .18em;
  color: var(--cinnabar);
  margin: 0 0 10px;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--cinnabar-soft);
}

.page-about .about-mast h1 {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(28px, 7vw, 50px);
  line-height: 1.22;
  letter-spacing: -0.01em;
  margin: 0 0 16px;
  max-width: 15em;
  color: var(--ink-deep);
}

.page-about .about-mast .lede {
  font-size: var(--t-3);
  line-height: 1.78;
  color: var(--ink-mid);
  max-width: 33em;
  margin: 0;
}

.page-about .mast-facts {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .mast-facts li {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 7px 12px;
  background: var(--paper);
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  font-size: var(--t-1);
  color: var(--water);
  letter-spacing: .02em;
}

.page-about .mast-facts b {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--t-4);
  font-weight: 600;
  color: var(--cinnabar);
  line-height: 1;
}

/* ---------- 两栏骨架 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .about-index {
  margin-bottom: 28px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--hair);
}

.page-about .about-index-title {
  margin: 0 0 10px;
  font-size: var(--t-1);
  letter-spacing: .16em;
  color: var(--water);
}

.page-about .about-index-list {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-index-list li {
  flex: 0 0 auto;
}

.page-about .about-index-list a {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  white-space: nowrap;
  padding: 6px 10px;
  background: var(--paper);
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  font-size: var(--t-1);
  color: var(--ink-mid);
  text-decoration: none;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

.page-about .about-index-list .idx {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--water);
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  color: var(--cinnabar);
  border-color: var(--cinnabar-soft);
}

.page-about .about-index-list a:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 2px;
}

/* ---------- 章节 ---------- */
.page-about .about-ch {
  margin-bottom: 52px;
}

.page-about .ch-head {
  display: flex;
  align-items: center;
  gap: 12px;
  border-top: 1px solid var(--ink-deep);
  padding-top: 14px;
  margin-bottom: 18px;
}

.page-about .ch-num {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--paper);
  background: var(--ink-deep);
  padding: 4px 8px;
  border-radius: 2px;
  line-height: 1;
}

.page-about .ch-head h2 {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(20px, 4.6vw, 28px);
  line-height: 1.28;
  letter-spacing: -0.01em;
  margin: 0;
  color: var(--ink-deep);
}

.page-about .ch-text {
  font-size: var(--t-2);
  line-height: 1.8;
  color: var(--ink-mid);
  max-width: 34em;
  margin: 0 0 18px;
}

.page-about .ch-next {
  display: inline-block;
  margin-top: 22px;
  padding-bottom: 3px;
  font-size: var(--t-2);
  color: var(--ink-mid);
  text-decoration: none;
  border-bottom: 1px solid var(--hair);
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

.page-about .ch-next:hover,
.page-about .ch-next:focus-visible {
  color: var(--cinnabar);
  border-color: var(--cinnabar);
}

.page-about .ch-next:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 3px;
}

/* ---------- 01 主张 ---------- */
.page-about .stance-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.page-about .principle-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .principle-list li {
  position: relative;
  padding: 14px 16px 14px 44px;
  background: var(--paper);
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  font-size: var(--t-2);
  line-height: 1.72;
  color: var(--ink-mid);
}

.page-about .principle-list li::before {
  content: "";
  position: absolute;
  left: 17px;
  top: 21px;
  width: 10px;
  height: 10px;
  border: 1.5px solid var(--cinnabar);
  border-radius: 50%;
}

.page-about .principle-list strong {
  display: block;
  font-family: var(--serif);
  font-size: var(--t-3);
  font-weight: 700;
  color: var(--ink-deep);
  margin-bottom: 3px;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 22px 0 0;
  padding: 0;
  background: var(--paper);
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-figure figcaption {
  padding: 10px 14px;
  border-top: 1px solid var(--hair);
  font-size: var(--t-1);
  line-height: 1.65;
  color: var(--water);
}

.page-about .about-figure--band {
  margin-top: 26px;
}

/* ---------- 02 流程 ---------- */
.page-about .step-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--hair);
}

.page-about .step-list li {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 12px;
  padding: 16px 0;
  border-bottom: 1px solid var(--hair);
}

.page-about .step-time {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 11px;
  letter-spacing: .02em;
  color: var(--cinnabar);
  padding-top: 3px;
  white-space: nowrap;
}

.page-about .step-list h3 {
  font-family: var(--serif);
  font-size: var(--t-3);
  font-weight: 700;
  color: var(--ink-deep);
  margin: 0 0 5px;
}

.page-about .step-list p {
  margin: 0;
  font-size: var(--t-2);
  line-height: 1.75;
  color: var(--ink-mid);
  max-width: 32em;
}

/* ---------- 03 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 18px;
  border-left: 1px solid var(--hair);
}

.page-about .timeline li {
  position: relative;
  padding: 0 0 26px 20px;
}

.page-about .timeline li::before {
  content: "";
  position: absolute;
  left: -23px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ink-mid);
}

.page-about .timeline li:last-child::before {
  background: var(--cinnabar);
  box-shadow: 0 0 0 3px var(--cinnabar-soft);
}

.page-about .tl-year {
  display: block;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--t-5);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--ink-deep);
  margin-bottom: 7px;
}

.page-about .timeline li:last-child .tl-year {
  color: var(--cinnabar);
}

.page-about .timeline h3 {
  font-family: var(--serif);
  font-size: var(--t-3);
  font-weight: 700;
  margin: 0 0 5px;
  color: var(--ink-deep);
}

.page-about .timeline p {
  margin: 0;
  font-size: var(--t-2);
  line-height: 1.75;
  color: var(--ink-mid);
  max-width: 32em;
}

/* ---------- 04 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-bottom: 26px;
}

.page-about .team-card {
  padding: 16px 16px 18px;
  background: var(--paper);
}

.page-about .team-num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 34px;
  font-weight: 600;
  line-height: 1;
  color: var(--cinnabar);
  margin: 0 0 8px;
}

.page-about .team-num small {
  font-family: var(--sans);
  font-size: var(--t-1);
  font-weight: 400;
  color: var(--water);
  margin-left: 3px;
}

.page-about .team-card h3,
.page-about .partner-stat h3 {
  font-family: var(--serif);
  font-size: var(--t-3);
  font-weight: 700;
  color: var(--ink-deep);
  margin: 0 0 6px;
}

.page-about .team-card p:not(.team-num),
.page-about .partner-stat p:not(.team-num) {
  margin: 0;
  font-size: var(--t-2);
  line-height: 1.72;
  color: var(--ink-mid);
}

.page-about .bar-list {
  display: grid;
  gap: 16px;
  padding: 18px 16px;
  background: var(--paper);
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.page-about .bar-label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 10px;
  margin: 0 0 7px;
  font-size: var(--t-1);
  color: var(--water);
  letter-spacing: .02em;
}

.page-about .bar-label b {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  font-size: var(--t-2);
  color: var(--ink-deep);
  white-space: nowrap;
}

.page-about .bar-track {
  display: block;
  height: 8px;
  background: var(--mist);
  border: 1px solid var(--hair);
  border-radius: 2px;
  overflow: hidden;
}

.page-about .bar-fill {
  display: block;
  height: 100%;
  background: var(--ink-mid);
}

.page-about .bar-fill--lime {
  background: var(--lime);
}

.page-about .bar-fill--red {
  background: var(--cinnabar);
}

/* ---------- 05 合作 ---------- */
.page-about .partner-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
}

.page-about .partner-stats {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .partner-stat {
  padding: 16px;
  background: var(--paper);
}

.page-about .handbook-card {
  padding: 20px 18px;
  background: var(--cinnabar-soft);
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.page-about .handbook-tag {
  display: inline-block;
  margin: 0 0 10px;
  padding: 3px 8px;
  font-size: 10px;
  letter-spacing: .16em;
  color: var(--paper);
  background: var(--cinnabar);
  border-radius: 2px;
}

.page-about .handbook-card h3 {
  font-family: var(--serif);
  font-size: var(--t-4);
  font-weight: 700;
  margin: 0 0 8px;
  color: var(--ink-deep);
}

.page-about .handbook-card p {
  margin: 0 0 14px;
  font-size: var(--t-2);
  line-height: 1.75;
  color: var(--ink-deep);
}

.page-about .handbook-link {
  font-size: var(--t-2);
  color: var(--ink-deep);
  text-decoration: none;
  border-bottom: 1px solid var(--ink-mid);
  padding-bottom: 2px;
}

.page-about .handbook-link:hover,
.page-about .handbook-link:focus-visible {
  color: var(--cinnabar);
  border-color: var(--cinnabar);
}

.page-about .handbook-link:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 3px;
}

/* ---------- 06 折叠条目 ---------- */
.page-about .fold-stack {
  border-top: 1px solid var(--hair);
}

.page-about .about-fold {
  border-bottom: 1px solid var(--hair);
}

.page-about .about-fold summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 15px 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--serif);
  font-weight: 700;
  font-size: var(--t-3);
  color: var(--ink-deep);
  transition: color .16s var(--ease);
}

.page-about .about-fold summary::-webkit-details-marker {
  display: none;
}

.page-about .about-fold summary::before {
  content: "+";
  flex: 0 0 auto;
  width: 14px;
  font-family: var(--mono);
  font-weight: 400;
  color: var(--cinnabar);
}

.page-about .about-fold[open] summary::before {
  content: "\2212";
}

.page-about .about-fold summary:hover {
  color: var(--cinnabar);
}

.page-about .about-fold summary:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 2px;
}

.page-about .about-fold .fold-body {
  padding: 0 0 18px 26px;
  font-size: var(--t-2);
  line-height: 1.8;
  color: var(--ink-mid);
  max-width: 34em;
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  margin-top: 44px;
  padding: 26px 20px 28px;
  background: var(--ink-deep);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.page-about .about-cta h2 {
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(20px, 4.6vw, 28px);
  line-height: 1.3;
  margin: 0 0 10px;
  color: var(--paper);
}

.page-about .about-cta p {
  margin: 0 0 20px;
  font-size: var(--t-2);
  line-height: 1.75;
  max-width: 32em;
  color: rgba(242, 245, 241, .76);
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-cta .btn--ghost {
  border-color: rgba(242, 245, 241, .38);
  color: var(--paper);
}

.page-about .about-cta .btn--ghost:hover,
.page-about .about-cta .btn--ghost:focus-visible {
  border-color: var(--paper);
  background: rgba(242, 245, 241, .1);
}

.page-about .about-cta .btn:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: 2px;
}

/* ---------- 平板 ---------- */
@media (min-width: 640px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .partner-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-figure--band,
  .page-about .about-figure--wide {
    margin-top: 28px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about {
    padding-bottom: 88px;
    background-size: 128px 128px;
  }

  .page-about .about-mast {
    padding-top: 26px;
    padding-bottom: 38px;
    margin-bottom: 8px;
  }

  .page-about .about-layout {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 48px;
    padding-top: 34px;
  }

  .page-about .about-index {
    position: relative;
    align-self: start;
    position: sticky;
    top: 28px;
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: 0;
    overflow: visible;
  }

  .page-about .about-index::before {
    content: "";
    position: absolute;
    left: 10px;
    top: 34px;
    bottom: 8px;
    width: 1px;
    background: var(--hair);
  }

  .page-about .about-index-list {
    display: block;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-index-list li {
    position: relative;
  }

  .page-about .about-index-list a {
    display: block;
    padding: 7px 0 7px 28px;
    background: none;
    border: 0;
    border-radius: 0;
  }

  .page-about .about-index-list .idx {
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 21px;
    text-align: center;
    background: var(--mist);
    padding: 2px 0;
    line-height: 1.2;
  }

  .page-about .about-body {
    max-width: 780px;
  }

  .page-about .stance-grid {
    grid-template-columns: minmax(0, 1.18fr) minmax(0, .82fr);
    gap: 34px;
    align-items: start;
  }

  .page-about .about-figure {
    margin-top: 0;
  }

  .page-about .about-figure--band,
  .page-about .about-figure--wide {
    margin-top: 30px;
  }

  .page-about .about-ch {
    margin-bottom: 64px;
  }

  .page-about .partner-grid {
    grid-template-columns: minmax(0, 1.42fr) minmax(0, .78fr);
    gap: 34px;
    align-items: start;
  }

  .page-about .about-cta {
    margin-top: 56px;
    padding: 34px 32px 36px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-layout {
    gap: 64px;
  }

  .page-about .team-grid {
    grid-template-columns: 1.12fr .94fr 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index-list a,
  .page-about .ch-next,
  .page-about .about-fold summary,
  .page-about .handbook-link {
    transition: none;
  }
}