.page-about {
  --about-line: var(--stroke);
  --about-gap: 24px;
  color: var(--fg-strong);
  display: block;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 24px 0 0;
}

.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 32px;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--fg-muted);
}

.page-about .breadcrumb li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-about .breadcrumb li + li::before {
  content: "/";
  color: var(--line);
}

.page-about .breadcrumb a {
  color: var(--fg-muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

.page-about h1 {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 6vw, 4.4rem);
  font-weight: 800;
  line-height: 1.04;
  letter-spacing: -0.01em;
  margin: 14px 0 20px;
  color: var(--fg-strong);
}

.page-about .about-lead {
  max-width: 60ch;
  margin: 0 0 28px;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--fg-muted);
}

.page-about .about-hero-figure {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-l);
  background: var(--bg-panel);
}

.page-about .about-hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.page-about .about-hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 16px;
  margin: 44px 0 0;
  padding-top: 28px;
  border-top: 1px solid var(--about-line);
}

.page-about .about-hero-stats > div {
  min-width: 0;
}

.page-about .about-hero-stats dt {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--fg-muted);
}

.page-about .about-hero-stats dd {
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-size: 1.125rem;
  color: var(--fg-strong);
}

.page-about .about-hero-stats .num {
  font-family: var(--font-mono);
  font-size: clamp(1.9rem, 5vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  padding: 88px 0 0;
}

.page-about .about-head {
  display: grid;
  gap: 14px;
  max-width: 72ch;
  margin-bottom: 36px;
}

.page-about .chapter-num {
  display: inline-block;
  width: fit-content;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--cyan);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .section-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3.2vw, 2.6rem);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.01em;
  color: var(--fg-strong);
}

.page-about .about-sub {
  margin: 0;
  max-width: 62ch;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--fg-muted);
}

.page-about .about-p {
  margin: 0 0 20px;
  max-width: 66ch;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--fg-muted);
}

.page-about .about-p:last-child {
  margin-bottom: 0;
}

/* ---------- 02 品牌定位 ---------- */
.page-about .scope-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
}

.page-about .scope-body {
  min-width: 0;
}

.page-about .client-list {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
}

.page-about .client-list li {
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  gap: 14px;
  padding: 20px 0;
  border-top: 1px solid var(--about-line);
}

.page-about .client-list li:last-child {
  border-bottom: 1px solid var(--about-line);
}

.page-about .client-list .idx {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .client-list h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--fg-strong);
}

.page-about .client-list p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--fg-muted);
}

.page-about .scope-side {
  align-self: start;
  padding: 26px 22px 28px;
  background: var(--bg-panel);
  border: 1px solid var(--about-line);
  border-radius: 4px var(--radius-l) var(--radius-l) var(--radius-l);
}

.page-about .scope-side-label {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .scope-cover {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .scope-cover li {
  position: relative;
  padding: 11px 0 11px 18px;
  border-top: 1px dashed var(--about-line);
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--fg-muted);
}

.page-about .scope-cover li:first-child {
  border-top: 0;
}

.page-about .scope-cover li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 17px;
  width: 7px;
  height: 7px;
  border-radius: 1px;
  background: var(--cyan);
}

/* ---------- 03 团队 ---------- */
.page-about .team-cards {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.page-about .team-card {
  position: relative;
  min-width: 0;
  padding: 26px 22px 28px;
  background: var(--bg-panel);
  border: 1px solid var(--about-line);
  border-radius: 18px 18px 18px 6px;
  transition: border-color 0.24s var(--ease), transform 0.24s var(--ease);
}

.page-about .team-card--b {
  border-radius: 18px 18px 6px 18px;
}

.page-about .team-card--c {
  border-radius: 24px 6px 24px 24px;
}

.page-about .team-card:hover,
.page-about .team-card:focus-within {
  border-color: var(--cyan);
  transform: translateY(-3px);
}

.page-about .team-tag {
  display: inline-block;
  margin-bottom: 14px;
  padding: 3px 8px;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-s);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .team-card h3 {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--fg-strong);
}

.page-about .team-card ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .team-card li {
  position: relative;
  padding: 11px 0 11px 16px;
  border-top: 1px dashed var(--about-line);
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--fg-muted);
}

.page-about .team-card li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  width: 5px;
  height: 5px;
  border-radius: 1px;
  background: var(--cyan-soft);
}

.page-about .team-figure {
  margin: 28px 0 0;
  overflow: hidden;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-l);
  background: var(--bg-panel);
}

.page-about .team-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

/* ---------- 04 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 68px minmax(0, 1fr);
  gap: 22px;
  padding-bottom: 18px;
}

.page-about .timeline-item::before {
  content: "";
  position: absolute;
  left: 66px;
  top: 14px;
  bottom: 0;
  width: 2px;
  background: var(--about-line);
}

.page-about .timeline-item:last-child::before {
  display: none;
}

.page-about .timeline-item::after {
  content: "";
  position: absolute;
  left: 60px;
  top: 9px;
  width: 14px;
  height: 14px;
  background: var(--ink);
  border: 2px solid var(--cyan);
  border-radius: 2px;
  transform: rotate(45deg);
}

.page-about .timeline-year {
  padding-top: 8px;
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .timeline-details {
  min-width: 0;
  border-top: 1px solid var(--about-line);
}

.page-about .timeline-details summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 44px;
  padding: 10px 0 12px;
  list-style: none;
  cursor: pointer;
  color: var(--fg-strong);
}

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

.page-about .timeline-details summary::after {
  content: "";
  flex: none;
  width: 9px;
  height: 9px;
  border-right: 2px solid var(--fg-muted);
  border-bottom: 2px solid var(--fg-muted);
  transform: rotate(45deg);
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .timeline-details[open] summary::after {
  transform: rotate(-135deg);
  border-color: var(--cyan);
}

.page-about .timeline-details summary:hover .timeline-title,
.page-about .timeline-details summary:focus-visible .timeline-title {
  color: var(--cyan-soft);
}

.page-about .timeline-title {
  font-family: var(--font-display);
  font-size: 1.1875rem;
  font-weight: 700;
  line-height: 1.35;
  transition: color 0.2s var(--ease);
}

.page-about .timeline-body {
  padding: 4px 0 18px;
  border-top: 1px dashed var(--about-line);
}

.page-about .timeline-body p {
  position: relative;
  margin: 14px 0 0;
  padding-left: 16px;
  max-width: 62ch;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--fg-muted);
}

.page-about .timeline-body p::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  bottom: 6px;
  width: 3px;
  background: var(--orange);
  border-radius: 2px;
}

.page-about .timeline-figure {
  margin: 36px 0 0;
  overflow: hidden;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-l);
  background: var(--bg-panel);
}

.page-about .timeline-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

/* ---------- 05 产出与交付 ---------- */
.page-about .output-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
}

.page-about .output-lead {
  min-width: 0;
}

.page-about .output-big {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: clamp(3rem, 9vw, 5.2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.page-about .output-big .unit {
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--fg-muted);
}

.page-about .output-caption {
  margin: 0;
  max-width: 40ch;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--fg-muted);
}

.page-about .deliver-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .deliver-list li {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 16px;
  padding: 18px 0;
  border-top: 1px solid var(--about-line);
}

.page-about .deliver-list li:last-child {
  border-bottom: 1px solid var(--about-line);
}

.page-about .deliver-idx {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .deliver-list h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--fg-strong);
}

.page-about .deliver-list p {
  margin: 0;
  max-width: 58ch;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--fg-muted);
}

.page-about .output-note {
  margin: 26px 0 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--fg-muted);
}

.page-about .output-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .output-note a:hover,
.page-about .output-note a:focus-visible {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

/* ---------- 06 合作生态 ---------- */
.page-about .partner-stats {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
  border-radius: var(--radius-l);
  overflow: hidden;
}

.page-about .partner-stat {
  padding: 32px 24px 34px;
  background: var(--bg-panel);
}

.page-about .partner-stat .stat-value {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: clamp(2.4rem, 7vw, 3.6rem);
  font-weight: 700;
  line-height: 1;
  color: var(--fg-strong);
  font-variant-numeric: tabular-nums;
}

.page-about .partner-stat .stat-value small {
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 500;
  color: var(--fg-muted);
}

.page-about .partner-stat .stat-note {
  margin: 0;
  max-width: 42ch;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--fg-muted);
}

.page-about .partner-modes {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
}

.page-about .partner-modes li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 18px 0;
  border-top: 1px solid var(--about-line);
}

.page-about .partner-modes li:last-child {
  border-bottom: 1px solid var(--about-line);
}

.page-about .partner-modes h3 {
  position: relative;
  margin: 0;
  padding-left: 18px;
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--fg-strong);
}

.page-about .partner-modes h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 8px;
  height: 3px;
  background: var(--cyan);
}

.page-about .partner-modes p {
  margin: 0;
  padding-left: 18px;
  max-width: 58ch;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--fg-muted);
}

/* ---------- 07 下一步 ---------- */
.page-about .about-next {
  padding-bottom: 96px;
}

.page-about .next-panel {
  display: grid;
  gap: 16px;
  justify-items: start;
  padding: 44px 26px 48px;
  background: var(--bg-panel);
  border: 1px solid var(--about-line);
  border-left: 4px solid var(--orange);
  border-radius: var(--radius-l);
}

.page-about .next-panel .about-p {
  margin: 0;
  max-width: 58ch;
}

.page-about .next-panel .btn {
  margin-top: 8px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }

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

  .page-about .partner-modes li {
    grid-template-columns: minmax(0, 0.6fr) minmax(0, 1.4fr);
    gap: 20px;
    align-items: baseline;
  }

  .page-about .next-panel {
    padding: 56px 48px 60px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    padding-top: 40px;
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-hero-stats {
    margin-top: 64px;
  }

  .page-about .about-section {
    padding-top: 120px;
  }

  .page-about .scope-grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 0.85fr);
    gap: 56px;
  }

  .page-about .team-cards {
    grid-template-columns: 1.15fr 0.85fr 1fr;
    gap: 18px;
  }

  .page-about .team-card--a {
    padding-bottom: 40px;
  }

  .page-about .output-grid {
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
    gap: 64px;
    align-items: start;
  }

  .page-about .timeline-item {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: 32px;
    padding-bottom: 8px;
  }

  .page-about .timeline-item::before {
    left: 94px;
  }

  .page-about .timeline-item::after {
    left: 88px;
  }

  .page-about .timeline-year {
    font-size: 1.0625rem;
  }
}

@media (min-width: 1200px) {
  .page-about .scope-grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 0.85fr);
  }

  .page-about .next-panel {
    padding: 72px 64px 76px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-card,
  .page-about .timeline-details summary::after {
    transition: none;
  }

  .page-about .team-card:hover,
  .page-about .team-card:focus-within {
    transform: none;
  }
}