.page-about {
  --about-track-w: 208px;
  --about-shell: 1240px;
  background:
    radial-gradient(120% 70% at 84% -8%, rgba(53, 242, 201, 0.10), transparent 58%),
    var(--ink);
  color: var(--paper);
}

/* ---------- 首屏 ---------- */
.page-about .about-head {
  max-width: var(--about-shell);
  margin: 0 auto;
  padding: calc(var(--header-h) + 44px) 20px 52px;
  border-bottom: 1px solid var(--line);
}

.page-about .head-grid {
  display: grid;
  gap: 32px;
  margin-top: 26px;
}

.page-about h1 {
  margin: 12px 0 0;
  font-size: clamp(34px, 7vw, 62px);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -0.03em;
  max-width: 16em;
}

.page-about .lede {
  margin: 20px 0 0;
  max-width: 46em;
  font-size: 17px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .head-side {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
}

.page-about .stat-card {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 16px 20px;
  background: var(--deep);
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 600;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

.page-about .stat-label {
  font-size: 13px;
  color: var(--muted);
  white-space: nowrap;
}

/* ---------- 主布局 ---------- */
.page-about .about-layout {
  max-width: var(--about-shell);
  margin: 0 auto;
  padding: 0 20px 72px;
}

.page-about .about-track {
  display: none;
}

.page-about .track-title {
  margin: 0 0 18px;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--muted);
}

.page-about .track-list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 20px;
  position: relative;
}

.page-about .track-list::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 8px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--line) 40%, rgba(28, 76, 64, 0) 100%);
}

.page-about .track-item {
  position: relative;
  margin-bottom: 15px;
}

.page-about .track-item::before {
  content: "";
  position: absolute;
  left: -20px;
  top: 7px;
  width: 9px;
  height: 9px;
  background: var(--ink);
  border: 1px solid var(--line);
  transform: rotate(45deg);
  transition: background-color 200ms ease, border-color 200ms ease;
}

.page-about .track-item:hover::before,
.page-about .track-item:focus-within::before {
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .track-link {
  display: inline-block;
  font-size: 14px;
  line-height: 1.5;
  color: var(--muted);
  text-decoration: none;
  transition: color 180ms ease;
}

.page-about .track-link:hover,
.page-about .track-link:focus-visible {
  color: var(--paper);
}

/* ---------- 区块通用 ---------- */
.page-about .about-section {
  padding: 48px 0;
  border-top: 1px solid var(--line);
}

.page-about .about-section:first-child {
  border-top: 0;
  padding-top: 40px;
}

.page-about .section-index {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about h2 {
  margin: 0;
  font-size: clamp(24px, 4vw, 36px);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.02em;
}

.page-about h3 {
  font-size: 19px;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.35;
}

.page-about .section-lede {
  margin: 16px 0 0;
  max-width: 42em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .prose p {
  margin: 0 0 18px;
  font-size: 16.5px;
  line-height: 1.9;
}

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

.page-about .wide-prose {
  margin-top: 24px;
  max-width: 44em;
}

.page-about .inline-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 242, 201, 0.4);
}

.page-about .inline-link:hover {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

/* ---------- 图文分栏 ---------- */
.page-about .split {
  display: grid;
  gap: 26px;
  margin-top: 28px;
}

.page-about .media-frame {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  background: var(--deep);
  box-shadow: var(--shadow-soft);
}

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

.page-about .media-caption {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 浏览路径 ---------- */
.page-about .filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 26px 0 20px;
}

.page-about .filter-chip {
  padding: 8px 15px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font-family: inherit;
  font-size: 13.5px;
  line-height: 1.4;
  cursor: pointer;
  transition: color 180ms ease, border-color 180ms ease, background-color 180ms ease;
}

.page-about .filter-chip:hover {
  color: var(--paper);
  border-color: var(--cyan);
}

.page-about .filter-chip[aria-pressed="true"] {
  background: rgba(53, 242, 201, 0.12);
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .path-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
}

.page-about .path-item {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px 22px;
  background: var(--deep);
  transition: border-color 180ms ease, transform 180ms ease;
}

.page-about .path-step {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .path-item h3 {
  margin: 0;
}

.page-about .path-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .link-arrow {
  margin-top: auto;
  padding-top: 6px;
  font-size: 14px;
  color: var(--cyan);
  text-decoration: none;
}

.page-about .link-arrow:hover {
  color: var(--cyan-soft);
}

.page-about .path-media {
  margin-top: 24px;
}

/* ---------- 时间轴 ---------- */
.page-about .milestones {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  position: relative;
}

.page-about .milestones::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 10px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--line) 34%, var(--line) 100%);
}

.page-about .milestone {
  position: relative;
  padding: 0 0 30px 34px;
}

.page-about .milestone:last-child {
  padding-bottom: 0;
}

.page-about .milestone::before {
  content: "";
  position: absolute;
  left: 1px;
  top: 5px;
  width: 11px;
  height: 11px;
  background: var(--ink);
  border: 1px solid var(--cyan);
  transform: rotate(45deg);
}

.page-about .milestone-stage {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .milestone h3 {
  margin: 0 0 8px;
  max-width: 26em;
}

.page-about .milestone p {
  margin: 0;
  max-width: 44em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  gap: 1px;
  margin-top: 26px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
}

.page-about .team-cell {
  padding: 22px 20px;
  background: var(--tactical);
}

.page-about .team-cell .num {
  display: block;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 600;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .team-cell h3 {
  margin: 10px 0 8px;
  font-size: 16px;
}

.page-about .team-cell p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 规模信息图 ---------- */
.page-about .scale-panel {
  display: grid;
  gap: 32px;
  margin-top: 28px;
}

.page-about .ring-wrap {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}

.page-about .ring {
  width: 168px;
  height: 168px;
  transform: rotate(-90deg);
}

.page-about .ring-track {
  fill: none;
  stroke: var(--line);
  stroke-width: 10;
}

.page-about .ring-value {
  fill: none;
  stroke: var(--cyan);
  stroke-width: 10;
  stroke-linecap: round;
  stroke-dasharray: 230.7 339.3;
}

.page-about .ring-center {
  position: absolute;
  top: 62px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  margin: 0;
}

.page-about .ring-num {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 600;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.page-about .ring-cap {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .ring-tip {
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  text-align: center;
  max-width: 15em;
  opacity: 0.55;
  transition: opacity 200ms ease, color 200ms ease;
}

.page-about .ring-wrap:hover .ring-tip,
.page-about .ring-wrap:focus-within .ring-tip {
  opacity: 1;
  color: var(--cyan-soft);
}

.page-about .bar-figure {
  align-self: center;
  width: 100%;
}

.page-about .bar-title {
  margin: 0 0 16px;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.page-about .bar-row {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr) 48px;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.page-about .bar-label {
  font-size: 13.5px;
  color: var(--muted);
}

.page-about .bar-track {
  display: block;
  height: 8px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--deep);
  overflow: hidden;
}

.page-about .bar-fill {
  display: block;
  height: 100%;
  border-radius: 999px;
}

.page-about .bar-fill--mobile {
  width: 68%;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--cyan-soft) 100%);
}

.page-about .bar-fill--desktop {
  width: 32%;
  background: var(--teal-dark);
}

.page-about .bar-num {
  font-family: var(--font-mono);
  font-size: 13.5px;
  color: var(--paper);
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.page-about .bar-note {
  margin: 18px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 口号三层 ---------- */
.page-about .slogan-stack {
  display: grid;
  gap: 1px;
  margin-top: 28px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
}

.page-about .slogan-card {
  padding: 26px 22px;
  background: var(--deep);
}

.page-about .slogan-layer {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--orange);
}

.page-about .slogan-card h3 {
  margin: 0 0 10px;
}

.page-about .slogan-card p {
  margin: 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  margin-top: 12px;
  padding: 34px 24px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background:
    linear-gradient(140deg, rgba(13, 58, 48, 0.85) 0%, rgba(7, 37, 31, 0.6) 60%),
    var(--deep);
}

.page-about .about-cta h2 {
  font-size: clamp(22px, 3.4vw, 30px);
}

.page-about .cta-lede {
  margin: 16px 0 0;
  max-width: 46em;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .cta-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .cta-note {
  margin: 20px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .slogan-stack {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .path-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .scale-panel {
    grid-template-columns: 240px minmax(0, 1fr);
    align-items: center;
    gap: 48px;
  }

  .page-about .bar-figure {
    align-self: center;
  }
}

@media (min-width: 900px) {
  .page-about .about-head {
    padding: calc(var(--header-h) + 64px) 32px 64px;
  }

  .page-about .head-grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 0.55fr);
    gap: 56px;
    align-items: end;
    margin-top: 32px;
  }

  .page-about .about-layout {
    display: grid;
    grid-template-columns: var(--about-track-w) minmax(0, 1fr);
    gap: 56px;
    align-items: start;
    padding: 0 32px 96px;
  }

  .page-about .about-track {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 32px);
    padding-top: 44px;
  }

  .page-about .about-section {
    padding: 64px 0;
  }

  .page-about .about-section:first-child {
    padding-top: 44px;
  }

  .page-about .split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .split--media-left .split-copy {
    order: 2;
  }

  .page-about .split--media-left .split-media {
    order: 1;
  }

  .page-about .about-cta {
    padding: 44px 40px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .track-item::before,
  .page-about .filter-chip,
  .page-about .ring-tip,
  .page-about .path-item {
    transition: none;
  }
}