.page-about {
  background: var(--bg-deep);
  color: var(--text);
  overflow-x: hidden;
}

.page-about .about-hero {
  padding-block: clamp(24px, 5vw, 56px) clamp(28px, 5vw, 52px);
}

.page-about .about-hero .eyebrow {
  margin-bottom: 18px;
}

.page-about h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 5.4vw, 58px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  margin: 0 0 20px;
  max-width: 22em;
}

.page-about .about-lead {
  font-family: var(--font-body);
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: var(--text-dim);
  max-width: 38em;
  margin: 0;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-top: clamp(28px, 5vw, 44px);
}

.page-about .stat-item {
  background: var(--bg-night);
  padding: 18px 16px 20px;
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-size: clamp(24px, 4.6vw, 34px);
  line-height: 1;
  color: var(--text);
  font-variant-numeric: tabular-nums;
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 6px;
  flex-wrap: wrap;
}

.page-about .stat-unit {
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 400;
  color: var(--cyan);
  letter-spacing: 0.04em;
}

.page-about .stat-label {
  margin: 10px 0 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-faint);
}

/* ---------- 非对称两栏 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
  padding-bottom: clamp(32px, 6vw, 72px);
}

.page-about .about-index {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 10px 0;
}

.page-about .about-index-label {
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--text-faint);
  margin: 0 0 8px;
  text-transform: uppercase;
}

.page-about .about-index ul {
  display: flex;
  gap: 16px;
  list-style: none;
  margin: 0;
  padding: 0 0 2px;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-index ul::-webkit-scrollbar {
  display: none;
}

.page-about .about-index a {
  display: block;
  white-space: nowrap;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.18s ease;
}

.page-about .about-index a:hover,
.page-about .about-index a:focus-visible {
  color: var(--cyan);
}

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

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding-block: clamp(32px, 6vw, 64px);
}

.page-about .about-sep {
  height: clamp(20px, 4vw, 34px);
  background: linear-gradient(
    to bottom right,
    transparent calc(50% - 1px),
    var(--line) 50%,
    rgba(199, 185, 154, 0.28) calc(50% + 1px),
    transparent calc(50% + 2px)
  );
}

.page-about .about-text {
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--text-dim);
  max-width: 38em;
  margin: 24px 0 0;
}

.page-about .about-media {
  margin-top: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

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

.page-about .media-caption {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-faint);
  margin: 10px 0 0;
  line-height: 1.6;
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .tl-rail {
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--line);
  margin: 0 0 20px 4px;
}

.page-about .tl-node {
  position: relative;
  appearance: none;
  background: none;
  border: 0;
  font: inherit;
  text-align: left;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 11px 12px 11px 20px;
  color: var(--text-dim);
  transition: color 0.18s ease, margin 0.18s ease;
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 50%;
  width: 7px;
  height: 7px;
  margin-top: -3.5px;
  background: var(--bg-deep);
  border: 1px solid var(--line);
  transform: rotate(45deg);
  transition: background 0.18s ease, border-color 0.18s ease;
}

.page-about .tl-node:nth-child(even) {
  margin-left: 14px;
}

.page-about .tl-node:hover {
  color: var(--text);
}

.page-about .tl-node.is-active {
  color: var(--text);
}

.page-about .tl-node.is-active::before {
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .tl-node:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .tl-idx {
  font-size: 12px;
  color: var(--text-faint);
  min-width: 58px;
}

.page-about .tl-node.is-active .tl-idx {
  color: var(--cyan);
}

.page-about .tl-name {
  font-size: 14.5px;
}

.page-about .tl-panels {
  display: grid;
  gap: 12px;
}

.page-about .tl-panel {
  border-left: 2px solid var(--line);
}

.page-about .tl-panel .panel-body p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .tl-panel .panel-title {
  font-size: 16px;
}

/* ---------- 三块主业 ---------- */
.page-about .biz-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 22px;
}

.page-about .biz-card .panel-head {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .biz-card .panel-title {
  font-size: 18px;
}

.page-about .biz-card .panel-body p {
  margin: 0 0 14px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .biz-link {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 211, 238, 0.4);
  padding-bottom: 2px;
}

.page-about .biz-link:hover,
.page-about .biz-link:focus-visible {
  border-bottom-color: var(--cyan);
}

/* ---------- 数据数值 ---------- */
.page-about .about-figs {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  margin-top: 28px;
}

.page-about .about-fig {
  background: var(--panel);
  padding: 20px 18px 22px;
}

.page-about .about-fig-num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 6vw, 44px);
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 5px;
  flex-wrap: wrap;
  border-bottom: 2px solid rgba(34, 211, 238, 0.35);
  padding-bottom: 10px;
}

.page-about .fig-unit {
  font-family: var(--font-body);
  font-size: 12px;
  color: var(--text-dim);
  letter-spacing: 0.03em;
}

.page-about .about-fig-label {
  margin: 12px 0 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-faint);
}

/* ---------- 折叠说明 ---------- */
.page-about .disclosure {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--panel-soft);
  margin-top: 12px;
  transition: border-color 0.18s ease;
}

.page-about .disclosure:hover {
  border-color: var(--violet);
}

.page-about .disclosure summary {
  cursor: pointer;
  list-style: none;
  padding: 14px 16px;
  font-size: 14.5px;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 10px;
}

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

.page-about .disclosure summary::before {
  content: "+";
  font-family: var(--font-mono);
  color: var(--orange);
  font-size: 16px;
  line-height: 1;
}

.page-about .disclosure[open] summary::before {
  content: "–";
}

.page-about .disclosure .disclosure-body {
  padding: 0 16px 16px 42px;
}

.page-about .disclosure .disclosure-body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-dim);
}

/* ---------- 通栏地带 ---------- */
.page-about .about-band {
  background: var(--bg-night);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding-block: clamp(28px, 5vw, 52px);
  margin-block: clamp(16px, 3vw, 32px);
}

.page-about .about-media-band {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .band-copy {
  margin-top: 22px;
  display: grid;
  gap: 14px;
}

.page-about .band-copy p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-dim);
  max-width: 38em;
}

/* ---------- 合作生态 ---------- */
.page-about .eco-map {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: 24px;
}

.page-about .eco-hub {
  border: 1px solid transparent;
  border-radius: var(--radius);
  padding: 18px;
  background:
    linear-gradient(var(--panel), var(--panel)) padding-box,
    linear-gradient(115deg, var(--violet), var(--cyan)) border-box;
}

.page-about .eco-hub-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 17px;
  color: var(--text);
}

.page-about .eco-hub-note {
  margin: 8px 0 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text-dim);
}

.page-about .eco-node {
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel-soft);
  padding: 16px 16px 18px;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.page-about .eco-node::after {
  content: "";
  position: absolute;
  left: 18px;
  top: -12px;
  width: 1px;
  height: 12px;
  background: var(--line);
}

.page-about .eco-node:hover,
.page-about .eco-node:focus-visible {
  border-color: var(--violet);
  transform: translateY(-2px);
  outline: none;
}

.page-about .eco-node-title {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .eco-node-name {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 16px;
  color: var(--text);
}

.page-about .eco-note {
  margin: 10px 0 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--text-faint);
}

.page-about .eco-node--service .eco-node-title {
  color: var(--orange);
}

/* ---------- 下一步 ---------- */
.page-about .next-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: 22px;
}

.page-about .next-card {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 14px;
  align-items: baseline;
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 16px;
  background: var(--panel-soft);
  transition: border-color 0.2s ease, transform 0.2s ease, background 0.2s ease;
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  border-color: var(--cyan);
  background: var(--panel);
  transform: translateY(-2px);
  outline: none;
}

.page-about .next-idx {
  font-size: 12px;
  color: var(--cyan);
}

.page-about .next-name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 16px;
  color: var(--text);
}

.page-about .next-desc {
  grid-column: 1 / -1;
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-faint);
  margin-top: 6px;
}

/* ---------- 桌面 ---------- */
@media (min-width: 760px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-figs {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .biz-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .next-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .band-copy {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: clamp(24px, 4vw, 48px);
  }

  .page-about .eco-map {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .eco-hub {
    grid-column: 1 / -1;
    padding: 22px 24px;
  }

  .page-about .about-section {
    padding-block: clamp(44px, 5vw, 76px);
  }
}

@media (min-width: 980px) {
  .page-about .about-layout {
    grid-template-columns: 216px minmax(0, 1fr);
    gap: clamp(32px, 5vw, 68px);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: 132px;
    border-top: 0;
    border-bottom: 0;
    padding: 0;
  }

  .page-about .about-index ul {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
  }

  .page-about .about-index a {
    white-space: normal;
    position: relative;
    padding: 9px 0 9px 16px;
    line-height: 1.5;
  }

  .page-about .about-index a::before {
    content: "";
    position: absolute;
    left: 0;
    top: 7px;
    bottom: 7px;
    width: 2px;
    background: var(--line);
    transition: background 0.2s ease;
  }

  .page-about .about-index a:hover::before,
  .page-about .about-index a:focus-visible::before {
    background: var(--violet);
  }

  .page-about .about-body--full {
    max-width: 100%;
  }

  .page-about .tl-panels {
    gap: 14px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-body {
    max-width: 62em;
  }
}