.page-about {
  --about-rail: 210px;
  --about-gap: clamp(22px, 3.2vw, 40px);
  position: relative;
}

/* 山地雾气层次的背景光 */
.page-about .about-atmos {
  position: absolute;
  inset: 0 0 auto 0;
  height: clamp(420px, 62vw, 760px);
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(120% 84% at 82% 0%, rgba(198, 242, 74, 0.10), transparent 58%),
    radial-gradient(96% 72% at 8% 14%, rgba(18, 51, 43, 0.92), transparent 72%),
    linear-gradient(180deg, rgba(18, 51, 43, 0.55), rgba(10, 29, 24, 0) 84%);
}

.page-about .about-shell {
  position: relative;
  z-index: 1;
  padding-top: clamp(26px, 4.4vw, 54px);
}

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

.page-about .about-rail__inner {
  border: 1px solid var(--line-soft);
  background: linear-gradient(180deg, rgba(18, 51, 43, 0.76), rgba(5, 18, 15, 0.6));
  padding: 18px 16px 20px;
}

.page-about .about-rail__label {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 10px 10px 12px;
  border-left: 2px solid transparent;
  color: var(--text-soft);
  font-size: 15px;
  line-height: 1.45;
  text-decoration: none;
  transition: color 140ms var(--ease), border-color 140ms var(--ease), background-color 140ms var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--text);
  border-left-color: var(--lime);
  background: rgba(198, 242, 74, 0.07);
  outline: none;
}

.page-about .about-rail__no {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--amber);
  flex: 0 0 auto;
}

.page-about .about-content {
  min-width: 0;
  padding-bottom: clamp(56px, 7vw, 96px);
}

/* 面包屑 */
.page-about .about-crumb {
  margin: 0 0 clamp(16px, 2.2vw, 26px);
}

.page-about .about-crumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

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

.page-about .about-crumb a {
  color: var(--muted);
  text-decoration: none;
  transition: color 140ms var(--ease);
}

.page-about .about-crumb a:hover,
.page-about .about-crumb a:focus-visible {
  color: var(--lime);
  outline: none;
}

.page-about .about-crumb [aria-current="page"] {
  color: var(--text-soft);
}

/* 标题区 */
.page-about .about-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 5.4vw, 62px);
  line-height: 1.07;
  letter-spacing: -0.022em;
  color: var(--text);
  max-width: 20ch;
}

.page-about .about-title em {
  font-style: normal;
  color: var(--lime);
}

.page-about .about-lede {
  margin: 20px 0 0;
  max-width: 62ch;
  font-size: clamp(16px, 1.45vw, 19px);
  line-height: 1.82;
  color: var(--text-soft);
}

.page-about .about-hero-media {
  margin: 32px 0 0;
}

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

/* 章节 */
.page-about .about-block {
  padding-top: clamp(40px, 5.4vw, 74px);
  scroll-margin-top: 96px;
}

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

.page-about .about-kicker {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--amber);
}

.page-about .about-h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 3vw, 38px);
  line-height: 1.2;
  letter-spacing: -0.016em;
  color: var(--text);
  max-width: 26ch;
}

.page-about .about-p {
  margin: 16px 0 0;
  max-width: 68ch;
  font-size: 17px;
  line-height: 1.78;
  color: var(--text-soft);
}

/* 三条业务主干 */
.page-about .about-pillars {
  margin: 26px 0 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-pillar {
  background: var(--ink);
  padding: 22px 20px 24px;
}

.page-about .about-pillar__no {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .about-pillar__t {
  margin: 10px 0 0;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text);
}

.page-about .about-pillar__d {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.74;
  color: var(--muted);
}

/* 数据条 */
.page-about .about-metrics {
  margin: 26px 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-metric {
  background: linear-gradient(180deg, rgba(18, 51, 43, 0.62), rgba(10, 29, 24, 0.92));
  padding: 20px 18px 22px;
}

.page-about .about-metric__v {
  font-family: var(--font-mono);
  font-size: clamp(24px, 2.8vw, 32px);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--lime);
  line-height: 1.1;
}

.page-about .about-metric__v small {
  font-size: 0.5em;
  color: var(--muted);
  margin-left: 3px;
  letter-spacing: 0;
}

.page-about .about-metric__l {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.66;
  color: var(--muted);
}

/* 团队分工 */
.page-about .about-roles {
  margin: 26px 0 0;
  display: grid;
  gap: 8px;
}

.page-about .about-role {
  border: 1px solid var(--line-soft);
  background: rgba(18, 51, 43, 0.4);
  transition: border-color 140ms var(--ease), background-color 140ms var(--ease);
}

.page-about .about-role[open] {
  border-color: var(--amber-dim);
  background: rgba(18, 51, 43, 0.72);
}

.page-about .about-role > summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
  transition: background-color 140ms var(--ease);
}

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

.page-about .about-role > summary::marker {
  content: "";
}

.page-about .about-role > summary:hover {
  background: rgba(198, 242, 74, 0.06);
}

.page-about .about-role > summary:focus-visible {
  outline: 1px solid var(--lime);
  outline-offset: -1px;
}

.page-about .about-role__name {
  flex: 0 0 auto;
  min-width: 88px;
  font-size: 15px;
  font-weight: 500;
  color: var(--text);
}

.page-about .about-role__track {
  flex: 1 1 auto;
  min-width: 48px;
  height: 6px;
  background: rgba(30, 74, 64, 0.78);
  overflow: hidden;
}

.page-about .about-role__fill {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--amber), var(--lime));
  transition: width 320ms var(--ease);
}

.page-about .about-role__count {
  flex: 0 0 auto;
  min-width: 30px;
  text-align: right;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--lime);
}

.page-about .about-role > summary::after {
  content: "+";
  flex: 0 0 auto;
  width: 16px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
  color: var(--amber);
}

.page-about .about-role[open] > summary::after {
  content: "−";
  color: var(--lime);
}

.page-about .about-role__body {
  padding: 0 16px 16px;
}

.page-about .about-role__body p {
  margin: 0;
  max-width: 64ch;
  font-size: 15px;
  line-height: 1.76;
  color: var(--muted);
}

/* 时间线 */
.page-about .about-timeline {
  margin: 30px 0 0;
  padding: 0 0 0 26px;
  list-style: none;
  position: relative;
  display: grid;
  gap: 30px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--amber-dim), var(--line));
}

.page-about .about-tl {
  position: relative;
  min-width: 0;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 0 4px rgba(242, 169, 59, 0.14);
  transition: background-color 140ms var(--ease), box-shadow 140ms var(--ease);
}

.page-about .about-tl:hover::before {
  background: var(--lime);
  box-shadow: 0 0 0 6px rgba(198, 242, 74, 0.2);
}

.page-about .about-tl__no {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--amber);
  transition: color 140ms var(--ease);
}

.page-about .about-tl:hover .about-tl__no {
  color: var(--lime);
}

.page-about .about-tl__t {
  margin: 6px 0 0;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--text);
}

.page-about .about-tl__d {
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.74;
  color: var(--muted);
}

.page-about .about-tl-media {
  margin: 34px 0 0;
}

/* 合作生态 */
.page-about .about-partner {
  margin: 26px 0 0;
  display: grid;
  gap: 26px;
}

.page-about .about-partner__text .about-p:first-child {
  margin-top: 0;
}

.page-about .about-facts {
  margin: 24px 0 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-fact {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 14px 16px;
  background: rgba(10, 29, 24, 0.72);
}

.page-about .about-fact__v {
  flex: 0 0 auto;
  min-width: 34px;
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  color: var(--amber);
  line-height: 1.1;
}

.page-about .about-fact__l {
  font-size: 14px;
  line-height: 1.66;
  color: var(--text-soft);
}

.page-about .about-partner__media {
  margin: 0;
}

/* 收尾入口 */
.page-about .about-outro {
  padding-bottom: clamp(16px, 3vw, 40px);
}

.page-about .about-next {
  margin: 26px 0 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-next__item {
  display: block;
  padding: 22px 20px 24px;
  background: var(--panel-2);
  color: var(--text);
  text-decoration: none;
  transition: background-color 140ms var(--ease);
}

.page-about .about-next__item:hover,
.page-about .about-next__item:focus-visible {
  background: rgba(198, 242, 74, 0.09);
  outline: none;
}

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

.page-about .about-next__t {
  display: block;
  margin-top: 10px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .about-next__d {
  display: block;
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .about-next__go {
  display: inline-block;
  margin-top: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--lime);
}

/* 平板及以上：左右分栏，左列索引固定 */
@media (min-width: 940px) {
  .page-about .about-grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
  }

  .page-about .about-rail {
    position: sticky;
    top: 92px;
  }

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

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

/* 宽屏：时间线转为横向版本演进带 */
@media (min-width: 1160px) {
  .page-about .about-timeline {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0;
    padding-left: 0;
    margin-top: 34px;
  }

  .page-about .about-timeline::before {
    left: 0;
    right: 0;
    top: 14px;
    bottom: auto;
    width: auto;
    height: 1px;
    background: linear-gradient(90deg, var(--amber-dim), var(--line) 72%, rgba(30, 74, 64, 0));
  }

  .page-about .about-tl {
    padding: 34px 16px 0 0;
  }

  .page-about .about-tl::before {
    left: 0;
    top: 10px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-partner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.8fr);
    gap: clamp(24px, 3vw, 40px);
    align-items: start;
  }
}

@media (min-width: 800px) and (max-width: 1179px) {
  .page-about .about-next {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1180px) {
  .page-about .about-next {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 560px) {
  .page-about .about-role__name {
    min-width: 0;
    font-size: 14px;
  }

  .page-about .about-role > summary {
    gap: 10px;
    padding: 14px 12px;
  }

  .page-about .about-role__track {
    min-width: 34px;
  }

  .page-about .about-role__body {
    padding: 0 12px 14px;
  }

  .page-about .about-fact {
    gap: 10px;
    padding: 12px 12px;
  }

  .page-about .about-fact__v {
    min-width: 26px;
    font-size: 19px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .about-role__fill,
  .page-about .about-tl::before,
  .page-about .about-tl__no,
  .page-about .about-next__item,
  .page-about .about-role,
  .page-about .about-role > summary {
    transition: none;
  }
}
<<<END>>>