.page-about {
  --about-rule: rgba(27, 21, 18, 0.16);
  --about-rule-dark: rgba(201, 211, 216, 0.22);
  --about-paper-card: #FFFDF7;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(18px, 3.5vw, 36px) clamp(40px, 7vw, 92px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(58% 66% at 80% 8%, rgba(25, 227, 255, 0.16), transparent 66%),
    radial-gradient(46% 56% at 6% 92%, rgba(255, 106, 42, 0.13), transparent 72%);
}

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

.page-about .about-crumb {
  margin-bottom: clamp(20px, 4vw, 34px);
  font-size: var(--step-1);
  letter-spacing: 0.04em;
  color: var(--grayblue);
}

.page-about .about-crumb a {
  color: var(--warm-white);
  text-decoration: none;
}

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

.page-about .about-hero-frame {
  position: relative;
  border: 1px solid var(--about-rule-dark);
  padding: clamp(18px, 3.2vw, 40px);
  background: linear-gradient(180deg, rgba(11, 42, 67, 0.72), rgba(6, 26, 43, 0.36));
}

.page-about .about-hero-frame::before,
.page-about .about-hero-frame::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border: 1px solid var(--cyan);
  opacity: 0.7;
}

.page-about .about-hero-frame::before {
  top: -1px;
  left: -1px;
  border-right: none;
  border-bottom: none;
}

.page-about .about-hero-frame::after {
  right: -1px;
  bottom: -1px;
  border-left: none;
  border-top: none;
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
  align-items: end;
}

.page-about .about-hero-copy .eyebrow {
  color: var(--cyan);
}

.page-about .about-hero-title {
  margin: 14px 0 0;
  font-size: clamp(38px, 8.4vw, 104px);
  line-height: 0.98;
  letter-spacing: -0.03em;
  color: var(--warm-white);
}

.page-about .about-lede {
  margin-top: clamp(18px, 2.6vw, 26px);
  max-width: 46ch;
  color: rgba(255, 248, 236, 0.86);
  font-size: clamp(16px, 1.6vw, 18px);
  line-height: 1.75;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .about-hero-media {
  margin: 0;
}

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

.page-about .about-hero-media .media-cap {
  margin-top: 10px;
  font-size: var(--step-1);
  color: var(--grayblue);
  letter-spacing: 0.03em;
}

.page-about .about-hero-stats {
  list-style: none;
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: clamp(18px, 2.6vw, 26px) 0 0;
  border-top: 1px dashed var(--about-rule-dark);
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
}

.page-about .about-hero-stats li {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-stat-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 700;
  line-height: 1;
  color: var(--warm-white);
}

.page-about .about-stat-unit {
  font-size: 0.5em;
  margin-left: 2px;
  color: var(--orange);
}

.page-about .about-stat-label {
  font-size: var(--step-1);
  color: var(--grayblue);
  letter-spacing: 0.04em;
}

/* ---------- 画册主体带 ---------- */
.page-about .about-band {
  background-color: var(--cream);
  background-image:
    repeating-linear-gradient(90deg, rgba(27, 21, 18, 0.045) 0 1px, transparent 1px 88px);
  color: var(--brown);
  padding-block: clamp(36px, 6vw, 84px) clamp(44px, 7vw, 96px);
}

.page-about .about-doc {
  display: grid;
  gap: clamp(26px, 4vw, 42px);
  align-items: start;
}

/* ---------- 章节索引 ---------- */
.page-about .about-index {
  background: var(--ink-800);
  color: var(--warm-white);
  padding: 16px 14px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .about-index-title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--sand);
}

.page-about .about-index-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

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

.page-about .about-index-list a {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 8px 10px;
  border: 1px solid var(--about-rule-dark);
  color: rgba(255, 248, 236, 0.86);
  text-decoration: none;
  font-size: var(--step-2);
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease), background-color var(--t-fast) var(--ease);
}

.page-about .about-index-num {
  font-family: var(--font-mono);
  font-size: var(--step-1);
  color: var(--cyan);
  letter-spacing: 0.06em;
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  color: var(--warm-white);
  border-color: var(--cyan);
  background-color: rgba(25, 227, 255, 0.12);
}

/* ---------- 正文区 ---------- */
.page-about .about-body {
  display: flex;
  flex-direction: column;
  gap: clamp(42px, 6.5vw, 88px);
  min-width: 0;
}

.page-about .about-section {
  scroll-margin-top: 88px;
}

.page-about .about-sec-head {
  display: grid;
  gap: 10px;
  padding-bottom: 16px;
  margin-bottom: clamp(20px, 3vw, 30px);
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-sec-head .eyebrow {
  color: var(--teal);
}

.page-about .about-sec-head .eyebrow--orange {
  color: var(--orange);
}

.page-about .about-sec-head .eyebrow--sand {
  color: #9A7A34;
}

.page-about .about-sec-head .eyebrow--red {
  color: var(--sig-red);
}

.page-about .about-h2 {
  margin: 0;
  font-size: clamp(27px, 4.2vw, 50px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--brown);
}

.page-about .about-prose {
  max-width: 68ch;
}

.page-about .about-prose p,
.page-about .about-section > p {
  margin: 0 0 16px;
  font-size: 17px;
  line-height: 1.78;
  color: var(--brown);
}

.page-about .about-section > p {
  max-width: 68ch;
}

.page-about .about-lead-in {
  margin: 0 0 clamp(20px, 3vw, 28px);
  font-size: var(--step-2);
  color: rgba(27, 21, 18, 0.72);
}

.page-about .about-note {
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 16px 18px;
  background: rgba(255, 106, 42, 0.09);
  border-left: 4px solid var(--orange);
  font-size: var(--step-2);
  line-height: 1.72;
  max-width: 68ch;
}

/* ---------- 三条内容线卡片 ---------- */
.page-about .about-lines {
  display: grid;
  gap: 16px;
  margin-top: clamp(24px, 3.6vw, 34px);
}

.page-about .about-line-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px 18px 22px;
  background: var(--about-paper-card);
  border: 1px solid var(--about-rule);
  border-left-width: 4px;
  text-decoration: none;
  color: var(--brown);
  transition: transform var(--t-mid) var(--ease), box-shadow var(--t-mid) var(--ease);
}

.page-about .about-line-card--cyan {
  border-left-color: var(--teal);
}

.page-about .about-line-card--orange {
  border-left-color: var(--orange);
}

.page-about .about-line-card--red {
  border-left-color: var(--sig-red);
}

.page-about .about-line-card h3 {
  margin: 0;
  font-size: var(--step-3);
  line-height: 1.3;
  font-weight: 700;
}

.page-about .about-line-card p {
  margin: 0;
  font-size: var(--step-2);
  line-height: 1.72;
  color: rgba(27, 21, 18, 0.78);
}

.page-about .about-card-more {
  margin-top: auto;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.08em;
  color: var(--teal);
}

.page-about .about-line-card:hover,
.page-about .about-line-card:focus-visible {
  transform: translateY(-3px);
  box-shadow: 0 12px 26px rgba(6, 26, 43, 0.14);
}

.page-about .about-line-card .tag {
  align-self: flex-start;
}

/* ---------- 生产线 ---------- */
.page-about .about-workflow-grid {
  display: grid;
  gap: clamp(20px, 3.4vw, 34px);
}

.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 4px;
}

.page-about .about-steps li {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 14px;
  padding: 16px 0;
  border-top: 1px dashed var(--about-rule);
}

.page-about .about-steps li:first-child {
  border-top: 1px solid var(--about-rule);
}

.page-about .about-step-num {
  font-family: var(--font-mono);
  font-size: var(--step-2);
  font-weight: 700;
  color: var(--orange);
  letter-spacing: 0.04em;
}

.page-about .about-steps h3 {
  margin: 0 0 6px;
  font-size: var(--step-3);
  font-weight: 700;
}

.page-about .about-steps p {
  margin: 0;
  font-size: var(--step-2);
  line-height: 1.72;
  color: rgba(27, 21, 18, 0.78);
}

.page-about .about-inline-figure {
  margin: clamp(24px, 3.6vw, 34px) 0 0;
}

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

.page-about .about-inline-figure .media-cap {
  margin-top: 10px;
  font-size: var(--step-1);
  color: rgba(27, 21, 18, 0.66);
  letter-spacing: 0.03em;
}

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

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 6px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--teal), var(--orange) 56%, var(--sig-red));
  opacity: 0.55;
}

.page-about .about-tl-item {
  position: relative;
  padding-left: 34px;
  padding-bottom: clamp(20px, 3vw, 30px);
}

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

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: 1px;
  top: 5px;
  width: 11px;
  height: 11px;
  transform: rotate(45deg);
  background: var(--cream);
  border: 1px solid var(--ink-800);
}

.page-about .about-tl-year {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(20px, 2.4vw, 28px);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--ink-800);
}

.page-about .about-tl-body {
  border: 1px solid var(--about-rule);
  background: var(--about-paper-card);
}

.page-about .about-tl-body summary {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 44px;
  padding: 12px 14px;
  cursor: pointer;
  list-style: none;
  font-size: var(--step-2);
  font-weight: 600;
  color: var(--brown);
}

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

.page-about .about-tl-title {
  flex: 1 1 auto;
}

.page-about .about-tl-body summary::after {
  content: "＋";
  font-family: var(--font-mono);
  color: var(--sig-red);
  font-size: var(--step-3);
  line-height: 1;
}

.page-about .about-tl-body[open] summary::after {
  content: "－";
}

.page-about .about-tl-body summary:hover,
.page-about .about-tl-body summary:focus-visible {
  background: rgba(232, 67, 46, 0.07);
}

.page-about .about-tl-body p {
  margin: 0;
  padding: 0 14px 16px;
  font-size: var(--step-2);
  line-height: 1.75;
  color: rgba(27, 21, 18, 0.8);
  max-width: 62ch;
}

/* ---------- 团队关系图 ---------- */
.page-about .about-tree-wrap {
  margin-top: clamp(22px, 3.4vw, 32px);
  padding: 16px;
  background: rgba(11, 42, 67, 0.06);
  border: 1px solid var(--about-rule);
  overflow-x: auto;
}

.page-about .about-tree {
  display: block;
  width: 100%;
  min-width: 560px;
  height: auto;
}

.page-about .about-tree-link {
  fill: none;
  stroke: var(--teal);
  stroke-width: 1.5;
  stroke-dasharray: 4 4;
  opacity: 0.7;
}

.page-about .about-tree rect {
  fill: var(--about-paper-card);
  stroke: var(--teal);
  stroke-width: 1.5;
}

.page-about .about-tree text {
  font-family: var(--font-body);
  fill: var(--brown);
}

.page-about .about-tree-k {
  font-size: 16px;
  font-weight: 700;
}

.page-about .about-tree-v {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  fill: var(--ink-800);
}

.page-about .about-tree-d {
  font-size: 12.5px;
  fill: rgba(27, 21, 18, 0.72);
}

.page-about .about-tree-node:focus-visible rect,
.page-about .about-tree-node:focus rect {
  stroke: var(--orange);
  stroke-width: 3;
}

.page-about .about-rhythm {
  display: grid;
  gap: 14px;
  margin-top: clamp(22px, 3.4vw, 30px);
}

.page-about .about-rhythm-item {
  padding: 18px 16px;
  background: var(--about-paper-card);
  border: 1px solid var(--about-rule);
  border-top: 3px solid var(--teal);
}

.page-about .about-rhythm-item:nth-child(2) {
  border-top-color: var(--orange);
}

.page-about .about-rhythm-item:nth-child(3) {
  border-top-color: var(--sig-red);
}

.page-about .about-rhythm-item .tag {
  display: inline-flex;
  margin: 0 0 8px;
}

.page-about .about-rhythm-item h3 {
  margin: 0 0 8px;
  font-size: var(--step-3);
  font-weight: 700;
}

.page-about .about-rhythm-item p {
  margin: 0;
  font-size: var(--step-2);
  line-height: 1.72;
  color: rgba(27, 21, 18, 0.78);
}

/* ---------- 合作生态 ---------- */
.page-about .about-partner-grid {
  display: grid;
  gap: clamp(20px, 3.4vw, 32px);
  align-items: start;
}

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

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

.page-about .about-partner-figure .media-cap {
  margin-top: 10px;
  font-size: var(--step-1);
  color: rgba(27, 21, 18, 0.66);
  letter-spacing: 0.03em;
}

.page-about .about-coop {
  list-style: none;
  margin: clamp(24px, 3.6vw, 34px) 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-coop li {
  padding: 18px 16px 20px;
  background: var(--ink-800);
  color: var(--warm-white);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
}

.page-about .about-coop .tag {
  display: inline-flex;
  margin: 0 0 10px;
}

.page-about .about-coop h3 {
  margin: 0 0 8px;
  font-size: var(--step-3);
  font-weight: 700;
  color: var(--warm-white);
}

.page-about .about-coop p {
  margin: 0;
  font-size: var(--step-2);
  line-height: 1.72;
  color: rgba(255, 248, 236, 0.82);
}

/* ---------- 结尾面板 ---------- */
.page-about .about-cta {
  background: var(--ink-900);
  color: var(--warm-white);
  padding: clamp(24px, 4vw, 44px);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
  border-left: 4px solid var(--orange);
}

.page-about .about-cta .eyebrow {
  margin: 0 0 12px;
}

.page-about .about-cta .about-h2 {
  color: var(--warm-white);
}

.page-about .about-cta p {
  margin: 16px 0 0;
  max-width: 62ch;
  font-size: 17px;
  line-height: 1.78;
  color: rgba(255, 248, 236, 0.84);
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 28px);
}

/* ---------- 断点 ---------- */
@media (min-width: 620px) {
  .page-about .about-lines {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.9fr);
  }

  .page-about .about-doc {
    grid-template-columns: 214px minmax(0, 1fr);
    gap: clamp(32px, 4.6vw, 64px);
  }

  .page-about .about-index {
    position: sticky;
    top: 88px;
    padding: 20px 16px 24px;
  }

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

  .page-about .about-index-list li {
    flex: none;
  }

  .page-about .about-index-list a {
    border: none;
    border-left: 2px solid transparent;
    padding: 9px 6px;
    font-size: var(--step-2);
  }

  .page-about .about-index-list a:hover,
  .page-about .about-index-list a:focus-visible {
    border-left-color: var(--cyan);
    background-color: rgba(25, 227, 255, 0.1);
  }

  .page-about .about-workflow-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
    align-items: start;
  }

  .page-about .about-partner-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  }

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

@media (min-width: 1080px) {
  .page-about .about-lines {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-line-card {
    transition: none;
  }

  .page-about .about-line-card:hover,
  .page-about .about-line-card:focus-visible {
    transform: none;
  }
}
<<<END>>>