.page-about {
  --about-pad: clamp(44px, 7vw, 96px);
  --about-cell: clamp(26px, 5vw, 56px);
  background: var(--pitch);
  color: var(--fg);
  font-family: var(--font-sans);
}

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

.page-about a {
  color: var(--lime);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: calc(var(--header-room) + 24px) 0 clamp(32px, 5vw, 56px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(90% 70% at 88% 6%, rgba(184, 255, 60, 0.16), transparent 62%),
    linear-gradient(180deg, var(--pitch) 0%, var(--ink) 100%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -12%;
  width: 72%;
  height: 150%;
  pointer-events: none;
  background: repeating-linear-gradient(114deg, rgba(184, 255, 60, 0.07) 0 1px, transparent 1px 48px);
}

.page-about .about-hero .container {
  position: relative;
  z-index: 1;
}

.page-about .breadcrumb {
  margin-bottom: clamp(20px, 4vw, 36px);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .breadcrumb-list li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

.page-about .breadcrumb-link {
  color: var(--muted);
  text-decoration: none;
}

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

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 5vw, 48px);
  align-items: start;
}

.page-about .eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--lime);
}

.page-about .about-title {
  margin: 0 0 20px;
  font-size: clamp(34px, 6.4vw, 68px);
  line-height: 1.04;
  letter-spacing: -0.03em;
  font-weight: 900;
  color: var(--white);
}

.page-about .about-title .hl {
  color: var(--lime);
}

.page-about .about-lede {
  margin: 0;
  max-width: 37em;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-hero-figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--card);
  padding: 12px;
}

.page-about .about-hero-figure .img-frame {
  margin: 0;
}

.page-about .about-hero-figure .img-caption {
  margin: 10px 2px 0;
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(28px, 5vw, 44px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

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

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 4.6vw, 42px);
  line-height: 1;
  color: var(--lime);
}

.page-about .about-stat-label {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .about-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 22px;
}

.page-about .about-jump a {
  display: inline-block;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.16s, border-color 0.16s, background 0.16s;
}

.page-about .about-jump a:hover,
.page-about .about-jump a:focus-visible {
  color: var(--ink);
  background: var(--lime);
  border-color: var(--lime);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  padding: var(--about-pad) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-section--last {
  border-bottom: 0;
}

.page-about .section-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: start;
  gap: 14px clamp(14px, 3vw, 28px);
  margin-bottom: clamp(22px, 4vw, 36px);
}

.page-about .section-num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 5vw, 52px);
  line-height: 0.9;
  color: var(--line);
  letter-spacing: -0.02em;
}

.page-about .section-title {
  margin: 0;
  font-size: clamp(24px, 3.6vw, 40px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  font-weight: 900;
  color: var(--white);
}

.page-about .about-lead {
  margin: 0 0 clamp(22px, 4vw, 34px);
  max-width: 40em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 01 起点 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 4vw, 40px);
}

.page-about .about-split-main p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.82;
  color: var(--fg);
}

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

.page-about .about-note {
  border-left: 2px solid var(--lime);
  border-top: 1px solid var(--line);
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--card);
  padding: 20px 22px;
}

.page-about .about-note-k {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--orange);
}

.page-about .about-note-v {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--fg);
}

/* ---------- 02 能力地图 ---------- */
.page-about .about-tree-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 28px);
  align-items: start;
}

.page-about .about-tree-scroll {
  overflow-x: auto;
  overflow-y: hidden;
  border: 1px solid var(--line);
  background-color: var(--card);
  background-image:
    linear-gradient(rgba(30, 59, 49, 0.55) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 59, 49, 0.55) 1px, transparent 1px);
  background-size: 100% 44px, 44px 100%;
  padding: 14px;
}

.page-about .about-tree {
  display: block;
  width: 100%;
  min-width: 600px;
  height: auto;
}

.page-about .tree-line {
  fill: none;
  stroke: var(--lime-dim);
  stroke-width: 1.5;
}

.page-about .tree-line--dash {
  stroke: var(--orange-dim);
  stroke-dasharray: 5 6;
}

.page-about .tree-joint {
  fill: var(--lime);
}

.page-about .tree-node rect {
  fill: var(--pitch);
  stroke: var(--line);
  stroke-width: 1.5;
  transition: stroke 0.18s ease, fill 0.18s ease;
}

.page-about .tree-node:hover rect,
.page-about .tree-node:focus rect,
.page-about .tree-node:focus-visible rect {
  stroke: var(--lime);
  fill: #0f3527;
}

.page-about .tree-node:focus {
  outline: none;
}

.page-about .tree-tag {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  fill: var(--lime);
}

.page-about .tree-label {
  font-family: var(--font-sans);
  font-size: 28px;
  font-weight: 900;
  fill: var(--white);
}

.page-about .tree-desc {
  font-family: var(--font-sans);
  font-size: 15px;
  fill: var(--muted);
}

.page-about .about-tree-figure {
  margin: 0;
  padding: 10px;
  border: 1px solid var(--line);
  background: var(--card);
}

.page-about .about-tree-figure .img-frame {
  margin: 0;
}

.page-about .about-tree-figure .img-caption {
  margin: 10px 2px 0;
  font-size: 12px;
  line-height: 1.65;
  color: var(--muted);
}

.page-about .about-line-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: clamp(20px, 4vw, 30px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-line-list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  background: var(--pitch);
  padding: 18px 20px;
}

.page-about .about-line-k {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border: 1px solid var(--lime-dim);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--lime);
}

.page-about .about-line-list p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 03 认证 ---------- */
.page-about .about-cert-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 44px);
}

.page-about .cert-details {
  display: grid;
  gap: 10px;
}

.page-about .cert-item {
  border: 1px solid var(--line);
  background: var(--card);
}

.page-about .cert-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 14px 18px;
  cursor: pointer;
  font-size: 16px;
  font-weight: 700;
  color: var(--fg);
  list-style: none;
}

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

.page-about .cert-item summary:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: -2px;
}

.page-about .cert-plus {
  position: relative;
  flex: 0 0 auto;
  width: 14px;
  height: 14px;
}

.page-about .cert-plus::before,
.page-about .cert-plus::after {
  content: "";
  position: absolute;
  background: var(--lime);
  transition: transform 0.18s ease;
}

.page-about .cert-plus::before {
  top: 6px;
  left: 0;
  width: 14px;
  height: 1.5px;
}

.page-about .cert-plus::after {
  top: 0;
  left: 6px;
  width: 1.5px;
  height: 14px;
}

.page-about .cert-item[open] .cert-plus::after {
  transform: scaleY(0);
}

.page-about .cert-item p {
  margin: 0;
  padding: 0 18px 18px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-cert-matrix {
  border: 1px solid var(--line);
  background: var(--card);
  padding: 18px;
}

.page-about .about-cert-tip {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .cert-grid {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: 6px;
}

.page-about .cert-cell {
  position: relative;
  display: block;
  aspect-ratio: 1 / 1;
  border: 1px solid var(--line);
  border-radius: 1px;
  background: var(--pitch);
  transition: background 0.16s ease, border-color 0.16s ease;
}

.page-about .cert-cell:nth-child(6n + 1) {
  background: rgba(184, 255, 60, 0.12);
}

.page-about .cert-cell:hover,
.page-about .cert-cell:focus-visible {
  background: var(--lime);
  border-color: var(--lime);
  outline: none;
}

.page-about .cert-cell::after {
  content: attr(data-tip);
  position: absolute;
  bottom: calc(100% + 7px);
  left: 50%;
  z-index: 4;
  padding: 4px 8px;
  border: 1px solid var(--lime-dim);
  background: var(--ink);
  color: var(--fg);
  font-size: 11px;
  line-height: 1.4;
  white-space: nowrap;
  opacity: 0;
  transform: translate(-50%, 4px);
  transition: opacity 0.16s ease, transform 0.16s ease;
  pointer-events: none;
}

.page-about .cert-cell:hover::after,
.page-about .cert-cell:focus-visible::after {
  opacity: 1;
  transform: translate(-50%, 0);
}

.page-about .about-cert-foot {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--orange);
}

/* ---------- 04 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .team-card {
  border: 1px solid var(--line);
  border-top: 2px solid var(--lime-dim);
  background: var(--card);
  padding: 20px;
}

.page-about .team-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1;
  color: var(--lime);
}

.page-about .team-name {
  margin: 12px 0 8px;
  font-size: 19px;
  font-weight: 800;
  color: var(--white);
}

.page-about .team-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-team-figure {
  margin: clamp(24px, 4vw, 36px) 0 0;
  padding: 12px;
  border: 1px solid var(--line);
  background: var(--card);
}

.page-about .about-team-figure .img-frame {
  margin: 0;
}

.page-about .about-team-figure .img-caption {
  margin: 10px 2px 0;
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 05 时间线 ---------- */
.page-about .timeline-scroll {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 10px 0 6px;
  scroll-snap-type: x proximity;
}

.page-about .timeline-scroll:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: 4px;
}

.page-about .timeline {
  display: flex;
  gap: 0;
  min-width: 780px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tl-item {
  position: relative;
  flex: 1 1 0;
  min-width: 152px;
  padding: 30px 20px 0 0;
  border-top: 1px solid var(--line);
  scroll-snap-align: start;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  top: -5px;
  left: 0;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--lime);
  box-shadow: 0 0 0 4px rgba(184, 255, 60, 0.14);
}

.page-about .tl-item--now::before {
  background: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 154, 60, 0.16);
}

.page-about .tl-year {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(24px, 3vw, 32px);
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .tl-item--now .tl-year {
  color: var(--orange);
}

.page-about .tl-title {
  margin: 10px 0 8px;
  font-size: 16px;
  font-weight: 800;
  line-height: 1.4;
  color: var(--fg);
}

.page-about .tl-item p {
  margin: 0;
  font-size: 13px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .timeline-hint {
  margin: 14px 0 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--line);
}

/* ---------- 06 合作生态 ---------- */
.page-about .about-eco {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 4vw, 36px);
  align-items: start;
}

.page-about .about-eco-main p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.82;
  color: var(--fg);
}

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

.page-about .about-eco-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-eco-stats li {
  background: var(--card);
  padding: 16px 16px 18px;
}

.page-about .eco-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.4vw, 34px);
  line-height: 1;
  color: var(--lime);
}

.page-about .eco-unit {
  font-size: 0.55em;
  margin-left: 2px;
}

.page-about .eco-label {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .about-eco-note {
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 16px 18px;
  border-left: 2px solid var(--orange);
  background: rgba(255, 154, 60, 0.06);
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-eco-note a {
  color: var(--lime);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 07 承诺 ---------- */
.page-about .promise-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .promise-item {
  background: var(--pitch);
  padding: 22px 20px;
}

.page-about .promise-k {
  display: inline-block;
  margin-bottom: 12px;
  padding: 3px 10px;
  border: 1px solid var(--lime-dim);
  border-radius: var(--pill);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--lime);
}

.page-about .promise-item h3 {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 800;
  line-height: 1.4;
  color: var(--white);
}

.page-about .promise-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-cta {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  align-items: center;
  margin-top: clamp(24px, 4vw, 36px);
  padding: 24px;
  border: 1px solid var(--line);
  background:
    radial-gradient(120% 140% at 100% 0%, rgba(184, 255, 60, 0.14), transparent 58%),
    var(--card);
}

.page-about .about-cta-text {
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--fg);
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-line-list li {
    grid-template-columns: 1fr;
  }

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

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

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    padding: 28px;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .about-hero-figure {
    margin-top: 46px;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 8fr) minmax(0, 4fr);
  }

  .page-about .about-tree-layout {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .about-cert-layout {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .about-eco {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .section-head {
    grid-template-columns: 96px minmax(0, 1fr);
    align-items: baseline;
  }
}

@media (min-width: 1080px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    align-items: start;
  }

  .page-about .team-card:nth-child(even) {
    margin-top: 26px;
  }

  .page-about .about-cert-matrix {
    padding: 22px;
  }
}

@media (max-width: 479px) {
  .page-about .about-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .cert-grid {
    gap: 4px;
  }

  .page-about .cert-cell::after {
    font-size: 10px;
  }

  .page-about .about-tree {
    min-width: 560px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .cert-cell,
  .page-about .cert-cell::after,
  .page-about .cert-plus::before,
  .page-about .cert-plus::after,
  .page-about .tree-node rect,
  .page-about .about-jump a {
    transition: none;
  }
}