.page-about {
  background: var(--night);
  color: var(--ice);
  font-family: var(--font-body);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding: clamp(16px, 4vw, 28px) 0 clamp(46px, 8vw, 92px);
  background:
    radial-gradient(115% 85% at 6% 0%, rgba(45, 226, 197, 0.14), transparent 58%),
    radial-gradient(90% 75% at 98% 6%, rgba(255, 122, 61, 0.17), transparent 62%),
    var(--night);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.page-about .ab-hero-frame {
  position: relative;
  margin-top: clamp(16px, 4vw, 32px);
  padding: clamp(20px, 5vw, 52px);
  border: 1px solid var(--line-strong);
  background: linear-gradient(180deg, rgba(17, 26, 58, 0.78), rgba(11, 16, 38, 0.28));
}

.page-about .ab-hero-frame::before,
.page-about .ab-hero-frame::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border: 1px solid var(--cyan);
  pointer-events: none;
}

.page-about .ab-hero-frame::before {
  top: -1px;
  left: -1px;
  border-right: 0;
  border-bottom: 0;
}

.page-about .ab-hero-frame::after {
  right: -1px;
  bottom: -1px;
  border-top: 0;
  border-left: 0;
}

.page-about .ab-hero-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  flex-wrap: wrap;
}

.page-about .ab-hero-num {
  font-family: var(--font-mono);
  font-size: clamp(2.4rem, 9vw, 4.6rem);
  line-height: 0.9;
  letter-spacing: 0.04em;
  color: var(--orange);
}

.page-about .ab-hero-tag {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.34em;
  color: var(--cyan);
  padding-bottom: 4px;
  border-bottom: 1px solid rgba(45, 226, 197, 0.45);
}

.page-about .ab-hero h1 {
  margin: clamp(14px, 3vw, 26px) 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.85rem, 7.2vw, 3.85rem);
  line-height: 1.16;
  letter-spacing: 0.02em;
  color: var(--ice);
}

.page-about .ab-hero-lede {
  margin: clamp(14px, 3vw, 22px) 0 0;
  max-width: 48ch;
  font-size: clamp(15px, 2.6vw, 17px);
  line-height: 1.78;
  color: rgba(232, 237, 247, 0.82);
}

.page-about .ab-hero-foot {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 4vw, 34px);
}

.page-about .ab-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: clamp(14px, 2.4vw, 18px) 0 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-hero-meta li {
  position: relative;
  padding-left: 14px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.12em;
  color: var(--steel);
}

.page-about .ab-hero-meta li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.58em;
  width: 6px;
  height: 1px;
  background: var(--cyan);
}

.page-about .ab-hero-vertical {
  display: none;
}

/* ---------- 章节索引 ---------- */
.page-about .ab-index {
  background: var(--night-2);
  border-bottom: 1px solid var(--line);
}

.page-about .ab-index-inner {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-top: 10px;
  padding-bottom: 10px;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .ab-index-label {
  flex: none;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.3em;
  color: var(--steel);
}

.page-about .ab-index ol {
  display: flex;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-index a {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  color: var(--ice);
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .ab-index a span {
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--cyan);
}

.page-about .ab-index a:hover,
.page-about .ab-index a:focus-visible {
  border-color: var(--cyan);
  color: var(--cyan);
  background: rgba(45, 226, 197, 0.07);
}

/* ---------- 通用章节 ---------- */
.page-about .ab-block {
  position: relative;
  padding: clamp(50px, 9vw, 108px) 0;
}

.page-about .ab-block + .ab-block {
  border-top: 1px solid var(--line);
}

.page-about .ab-paper {
  background-color: var(--paper);
  background-image: radial-gradient(rgba(28, 21, 16, 0.055) 1px, transparent 1px);
  background-size: 4px 4px;
  color: var(--ink);
  border-top: 0;
}

.page-about .ab-chap-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: clamp(16px, 3vw, 26px);
}

.page-about .ab-chap-no {
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 4vw, 2.2rem);
  line-height: 1;
  color: var(--orange);
}

.page-about .ab-chap-rule {
  flex: 1 1 auto;
  max-width: 160px;
  height: 1px;
  background: var(--line-strong);
}

.page-about .ab-chap-name {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--steel);
}

.page-about .ab-paper .ab-chap-no {
  color: var(--rust);
}

.page-about .ab-paper .ab-chap-rule {
  background: var(--line-paper);
}

.page-about .ab-paper .ab-chap-name {
  color: rgba(28, 21, 16, 0.55);
}

.page-about h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.5rem, 5vw, 2.8rem);
  line-height: 1.24;
  letter-spacing: 0.01em;
}

.page-about h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.02rem, 3.2vw, 1.24rem);
  line-height: 1.4;
}

.page-about .ab-head-lede {
  margin: 12px 0 0;
  max-width: 58ch;
  font-size: clamp(14.5px, 2.5vw, 16.5px);
  line-height: 1.76;
  color: rgba(232, 237, 247, 0.78);
}

.page-about .ab-paper .ab-head-lede {
  color: rgba(28, 21, 16, 0.76);
}

.page-about .ab-copy p {
  margin: 0 0 1em;
  max-width: 56ch;
  font-size: clamp(15px, 2.6vw, 16.5px);
  line-height: 1.8;
  color: rgba(232, 237, 247, 0.8);
}

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

.page-about .ab-paper .ab-copy p {
  color: rgba(28, 21, 16, 0.82);
}

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

.page-about .ab-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line-strong);
  filter: saturate(0.92) contrast(1.05);
}

.page-about .ab-figure figcaption {
  margin-top: 10px;
  padding-left: 12px;
  border-left: 2px solid var(--orange);
  font-size: 12.5px;
  line-height: 1.62;
  color: var(--steel);
}

.page-about .ab-paper .ab-figure img {
  border-color: var(--line-paper);
}

.page-about .ab-paper .ab-figure figcaption {
  border-left-color: var(--rust);
  color: rgba(28, 21, 16, 0.62);
}

.page-about .ab-inline-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
  padding-bottom: 3px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(45, 226, 197, 0.45);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .ab-inline-link:hover,
.page-about .ab-inline-link:focus-visible {
  color: var(--amber);
  border-bottom-color: var(--amber);
}

.page-about .ab-paper .ab-inline-link {
  color: var(--rust);
  border-bottom-color: rgba(178, 58, 30, 0.4);
}

/* ---------- 01 品牌起源 ---------- */
.page-about .ab-origin-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 5vw, 52px);
}

.page-about .ab-origin-copy h2 {
  margin-bottom: clamp(14px, 2vw, 20px);
}

/* ---------- 02 服务人群 ---------- */
.page-about .ab-people-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 4vw, 40px);
  margin-top: clamp(22px, 4vw, 36px);
}

.page-about .ab-people-cards {
  display: grid;
  gap: 14px;
}

.page-about .ab-person {
  padding: clamp(18px, 3vw, 26px);
  border: 1px solid var(--line-paper);
  border-left: 3px solid var(--rust);
  background: rgba(255, 255, 255, 0.46);
}

.page-about .ab-person-no {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.26em;
  color: var(--rust);
}

.page-about .ab-person p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: rgba(28, 21, 16, 0.78);
}

.page-about .ab-person ul {
  display: grid;
  gap: 7px;
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-person li {
  position: relative;
  padding-left: 16px;
  font-size: 13.5px;
  line-height: 1.65;
  color: rgba(28, 21, 16, 0.7);
}

.page-about .ab-person li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.66em;
  width: 7px;
  height: 1px;
  background: var(--orange);
}

/* ---------- 03 内容运营 ---------- */
.page-about .ab-steps {
  display: grid;
  gap: 14px;
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-step {
  position: relative;
  padding: clamp(20px, 3vw, 28px);
  border: 1px solid var(--line);
  background: var(--night-2);
}

.page-about .ab-step::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), rgba(45, 226, 197, 0) 72%);
}

.page-about .ab-step-no {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.26em;
  color: var(--cyan);
}

.page-about .ab-step h3 {
  color: var(--ice);
}

.page-about .ab-step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.74;
  color: rgba(232, 237, 247, 0.76);
}

.page-about .ab-note {
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--orange);
  max-width: 56ch;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--steel);
}

/* ---------- 04 发展历程 ---------- */
.page-about .ab-track {
  display: grid;
  gap: 10px;
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-track li {
  position: relative;
  padding-left: 26px;
}

.page-about .ab-track li::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 18px;
  bottom: -10px;
  width: 1px;
  background: var(--line-paper);
}

.page-about .ab-track li:last-child::before {
  display: none;
}

.page-about .ab-track li::after {
  content: "";
  position: absolute;
  left: 0;
  top: 16px;
  width: 11px;
  height: 11px;
  border: 1px solid var(--rust);
  border-radius: 50%;
  background: var(--paper);
}

.page-about .ab-track details {
  border: 1px solid var(--line-paper);
  background: rgba(255, 255, 255, 0.46);
}

.page-about .ab-track summary {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 12px;
  padding: 14px 46px 14px 16px;
  list-style: none;
  cursor: pointer;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15.5px;
  line-height: 1.45;
  color: var(--ink);
  transition: background 0.2s var(--ease);
}

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

.page-about .ab-track summary::after {
  content: "+";
  position: absolute;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 17px;
  line-height: 1;
  color: var(--rust);
}

.page-about .ab-track details[open] summary::after {
  content: "–";
}

.page-about .ab-track summary:hover {
  background: rgba(255, 255, 255, 0.62);
}

.page-about .ab-track summary:focus-visible {
  outline: 2px solid var(--rust);
  outline-offset: -2px;
}

.page-about .ab-track-era {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 400;
  letter-spacing: 0.18em;
  color: var(--rust);
}

.page-about .ab-track-title {
  flex: 1 1 auto;
  min-width: 0;
}

.page-about .ab-track-body {
  padding: 12px 16px 16px;
  border-top: 1px solid var(--line-paper);
}

.page-about .ab-track-body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.74;
  color: rgba(28, 21, 16, 0.78);
}

/* ---------- 05 协作网络 ---------- */
.page-about .ab-network-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 44px);
  margin-top: clamp(6px, 2vw, 14px);
}

.page-about .ab-network-copy h2 {
  margin-bottom: clamp(14px, 2vw, 20px);
}

.page-about .ab-net-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  margin-top: clamp(16px, 3vw, 24px);
}

.page-about .ab-legend-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--steel);
}

.page-about .ab-dot {
  display: block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

.page-about .ab-dot--orange {
  background: var(--orange);
}

.page-about .ab-dot--cyan {
  background: var(--cyan);
}

.page-about .ab-network-figure {
  padding: clamp(16px, 3vw, 24px);
  border: 1px solid var(--line);
  background: linear-gradient(160deg, rgba(17, 26, 58, 0.9), rgba(11, 16, 38, 0.5));
}

.page-about .ab-net-svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .ab-net-caption {
  margin: 14px 0 0;
  font-size: 12px;
  line-height: 1.6;
  color: var(--steel);
}

.page-about .ab-figure--wide {
  margin-top: clamp(26px, 5vw, 46px);
}

/* ---------- 06 长期价值 ---------- */
.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(22px, 4vw, 36px);
  border: 1px solid var(--line-paper);
  background: var(--line-paper);
}

.page-about .ab-stat {
  display: grid;
  gap: 7px;
  align-content: start;
  padding: clamp(16px, 3vw, 26px);
  background: var(--paper);
}

.page-about .ab-stat-num {
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 5vw, 2.1rem);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--rust);
}

.page-about .ab-stat-label {
  font-size: 12.5px;
  line-height: 1.58;
  color: rgba(28, 21, 16, 0.66);
}

.page-about .ab-why-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(18px, 3vw, 28px);
  margin-top: clamp(26px, 4vw, 42px);
}

.page-about .ab-why-item {
  padding-top: 14px;
  border-top: 1px solid var(--line-paper);
}

.page-about .ab-why-item h3 {
  color: var(--ink);
}

.page-about .ab-why-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.74;
  color: rgba(28, 21, 16, 0.76);
}

.page-about .ab-cta {
  display: grid;
  gap: 16px;
  margin-top: clamp(30px, 5vw, 50px);
  padding: clamp(20px, 4vw, 32px);
  background: var(--night);
  border-left: 3px solid var(--amber);
}

.page-about .ab-cta-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.2rem, 4vw, 1.6rem);
  color: var(--ice);
}

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

/* ---------- 平板 ---------- */
@media (min-width: 700px) {
  .page-about .ab-why-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-about .ab-cta {
    grid-template-columns: 1fr auto;
    align-items: center;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 960px) {
  .page-about .ab-hero-vertical {
    display: block;
    position: absolute;
    top: 50%;
    right: calc(var(--gutter) * 0.3);
    transform: translateY(-50%);
    writing-mode: vertical-rl;
    letter-spacing: 0.42em;
    font-size: 11.5px;
    font-family: var(--font-mono);
    color: var(--steel);
    pointer-events: none;
  }

  .page-about .ab-origin-grid {
    grid-template-columns: 1.02fr 0.98fr;
    align-items: start;
    gap: clamp(32px, 5vw, 64px);
  }

  .page-about .ab-people-layout {
    grid-template-columns: 0.82fr 1.18fr;
    align-items: start;
  }

  .page-about .ab-network-grid {
    grid-template-columns: 1.06fr 0.94fr;
    align-items: center;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-index a,
  .page-about .ab-inline-link,
  .page-about .ab-track summary {
    transition: none;
  }
}
<<<END>>>