.page-about {
  --about-index-w: 216px;
  --about-y: clamp(36px, 5vw, 72px);
  --about-chapter-y: clamp(40px, 6vw, 88px);
  background-color: var(--bg);
  color: var(--text);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(16px, 3vw, 28px) 0 clamp(32px, 5vw, 64px);
  border-bottom: var(--rule);
  background:
    radial-gradient(120% 90% at 82% 0%, rgba(31, 224, 207, .14), transparent 62%),
    linear-gradient(180deg, var(--surface-deep), var(--bg) 78%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(90deg, rgba(30, 78, 102, .22) 0 1px, transparent 1px 96px),
    repeating-linear-gradient(0deg, rgba(30, 78, 102, .22) 0 1px, transparent 1px 96px);
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 92%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 92%);
  pointer-events: none;
}

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

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  margin-top: clamp(20px, 3.5vw, 36px);
}

.page-about .about-hero h1 {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: clamp(2rem, 6.2vw, 4.1rem);
  line-height: 1.08;
  letter-spacing: .045em;
  color: var(--ice);
  max-width: 14em;
}

.page-about .about-hero__intro {
  margin: clamp(16px, 2.5vw, 22px) 0 0;
  max-width: 40em;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.75;
  color: var(--text-soft);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

/* 摘要卡 */
.page-about .about-brief {
  border: var(--rule);
  background: linear-gradient(160deg, rgba(12, 42, 61, .96), rgba(8, 32, 49, .92));
  padding: clamp(16px, 2.4vw, 24px);
  position: relative;
}

.page-about .about-brief::after {
  content: "";
  position: absolute;
  top: -1px;
  right: -1px;
  width: 42px;
  height: 3px;
  background: var(--accent-warm);
}

.page-about .about-brief__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 12px;
  border-bottom: var(--rule-faint);
}

.page-about .about-brief__code {
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--muted);
}

.page-about .about-brief__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-brief__list li {
  display: grid;
  gap: 4px;
  padding: 12px 0;
  border-bottom: var(--rule-faint);
}

.page-about .about-brief__list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-brief__key {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--accent);
}

.page-about .about-brief__val {
  font-size: 14px;
  line-height: 1.65;
  color: var(--text-soft);
}

/* ---------- 数据带 ---------- */
.page-about .about-band {
  border-bottom: var(--rule);
  background: linear-gradient(90deg, rgba(12, 42, 61, .86), rgba(6, 24, 38, .92));
  position: relative;
}

.page-about .about-band::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 120px;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), transparent);
}

.page-about .about-band__track {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(200px, 1fr);
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  -webkit-overflow-scrolling: touch;
  scroll-snap-type: x mandatory;
}

.page-about .about-band__item {
  scroll-snap-align: start;
  padding: clamp(18px, 2.6vw, 26px) clamp(16px, 2vw, 24px);
  border-left: var(--rule-faint);
  display: grid;
  gap: 6px;
  align-content: start;
}

.page-about .about-band__item:first-child {
  border-left: 0;
}

.page-about .about-band__num {
  font-size: clamp(30px, 4.4vw, 46px);
  line-height: 1;
  color: var(--accent);
  font-weight: 600;
  letter-spacing: .02em;
}

.page-about .about-band__label {
  font-size: 12.5px;
  line-height: 1.55;
  color: var(--muted);
  max-width: 16em;
}

/* ---------- 粘性布局 ---------- */
.page-about .about-layout {
  display: grid;
  gap: clamp(24px, 4vw, 52px);
  padding: var(--about-y) 0 calc(var(--about-y) * 1.2);
}

.page-about .about-index__title {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  padding-bottom: 4px;
}

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

.page-about .about-index__list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: var(--rule-soft);
  background: rgba(12, 42, 61, .5);
  color: var(--text-soft);
  font-size: 13px;
  text-decoration: none;
  transition: border-color .2s ease, color .2s ease, background .2s ease;
}

.page-about .about-index__list a .mono {
  font-size: 11px;
  color: var(--accent);
  letter-spacing: .08em;
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  border-color: var(--accent);
  color: var(--ice);
  background: rgba(31, 224, 207, .1);
  outline: none;
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  padding-bottom: var(--about-chapter-y);
  border-bottom: var(--rule-faint);
  margin-bottom: var(--about-chapter-y);
}

.page-about .chapter:last-child {
  border-bottom: 0;
  margin-bottom: 0;
  padding-bottom: 0;
}

.page-about .chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(12px, 2vw, 22px);
  align-items: start;
  margin-bottom: clamp(22px, 3vw, 34px);
}

.page-about .chapter__no {
  font-size: clamp(26px, 4vw, 44px);
  line-height: .9;
  color: transparent;
  -webkit-text-stroke: 1px var(--line);
  letter-spacing: .02em;
}

.page-about .chapter h2 {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 3vw, 2.1rem);
  line-height: 1.25;
  letter-spacing: .035em;
  color: var(--ice);
}

.page-about .chapter__dek {
  margin: 12px 0 0;
  max-width: 46em;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--muted);
}

/* 定义列表 */
.page-about .about-defs {
  margin: 0 0 clamp(24px, 3.6vw, 36px);
  border-top: var(--rule-faint);
}

.page-about .about-defs__row {
  display: grid;
  gap: 6px;
  padding: 16px 0;
  border-bottom: var(--rule-faint);
}

.page-about .about-defs dt {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .02em;
  color: var(--ice);
}

.page-about .about-defs dt::before {
  content: "";
  display: inline-block;
  width: 14px;
  height: 1px;
  margin-right: 8px;
  vertical-align: middle;
  background: var(--accent-warm);
}

.page-about .about-defs dd {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--text-soft);
}

/* ---------- 图片 ---------- */
.page-about .about-fig {
  margin: clamp(24px, 3.5vw, 36px) 0 0;
}

.page-about .about-fig .figure__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: 0;
}

.page-about .about-fig--slim {
  margin-top: 0;
  margin-bottom: var(--about-chapter-y);
}

/* ---------- 流水线 ---------- */
.page-about .pipe {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: var(--rule);
}

.page-about .pipe__step {
  background: linear-gradient(180deg, rgba(12, 42, 61, .92), rgba(8, 32, 49, .92));
  padding: clamp(16px, 2.4vw, 24px);
  display: grid;
  gap: 8px;
  align-content: start;
  transition: background .25s ease;
}

.page-about .pipe__step:hover {
  background: linear-gradient(180deg, rgba(31, 224, 207, .1), rgba(8, 32, 49, .95));
}

.page-about .pipe__no {
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--accent);
}

.page-about .pipe h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 16.5px;
  letter-spacing: .04em;
  color: var(--ice);
}

.page-about .pipe p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--text-soft);
}

.page-about .about-split {
  margin-top: clamp(22px, 3vw, 32px);
  padding: clamp(16px, 2.4vw, 24px);
  border-left: 2px solid var(--accent-warm);
  background: rgba(255, 122, 26, .05);
}

.page-about .about-split__lead {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--accent-warm);
}

.page-about .about-split__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-soft);
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 clamp(16px, 3vw, 28px);
  border-left: 1px solid var(--line);
}

.page-about .timeline__item {
  position: relative;
  padding-bottom: 10px;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: calc(-1 * clamp(16px, 3vw, 28px) - 4px);
  top: 18px;
  width: 7px;
  height: 7px;
  background: var(--accent);
}

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

.page-about .timeline__details > summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 12px;
  align-items: start;
  padding: 10px 10px 10px 0;
  cursor: pointer;
  list-style: none;
  transition: background .2s ease;
}

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

.page-about .timeline__details > summary:hover,
.page-about .timeline__details > summary:focus-visible {
  background: rgba(31, 224, 207, .07);
  outline: none;
}

.page-about .timeline__year {
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--accent-warm);
  padding-top: 3px;
  white-space: nowrap;
}

.page-about .timeline__title {
  font-size: 15px;
  line-height: 1.6;
  color: var(--ice);
}

.page-about .timeline__toggle {
  position: relative;
  width: 14px;
  height: 14px;
  margin-top: 4px;
  border: 1px solid var(--line);
}

.page-about .timeline__toggle::before,
.page-about .timeline__toggle::after {
  content: "";
  position: absolute;
  background: var(--accent);
  transition: transform .22s ease, opacity .22s ease;
}

.page-about .timeline__toggle::before {
  left: 3px;
  top: 6px;
  width: 6px;
  height: 1px;
}

.page-about .timeline__toggle::after {
  left: 6px;
  top: 3px;
  width: 1px;
  height: 6px;
}

.page-about .timeline__details[open] .timeline__toggle::after {
  transform: scaleY(0);
  opacity: 0;
}

.page-about .timeline__more {
  padding: 0 0 14px 0;
  max-width: 48em;
}

.page-about .timeline__more p {
  margin: 0;
  font-size: 14px;
  line-height: 1.74;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
  align-items: center;
  margin-bottom: clamp(24px, 3.5vw, 36px);
}

.page-about .about-ring-wrap {
  display: flex;
  justify-content: center;
}

.page-about .about-ring-box {
  position: relative;
  width: min(260px, 72vw);
}

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

.page-about .about-ring__track {
  fill: none;
  stroke: rgba(30, 78, 102, .45);
  stroke-width: 12;
}

.page-about .about-ring__seg {
  fill: none;
  stroke-width: 12;
  transform: rotate(-90deg);
  transform-box: view-box;
  transform-origin: 70px 70px;
  transition: stroke-width .22s ease, opacity .22s ease;
  cursor: default;
}

.page-about .about-ring__seg:hover {
  stroke-width: 18;
}

.page-about .about-ring__seg--a {
  stroke: var(--accent);
  stroke-dasharray: 137.6 326.7;
  stroke-dashoffset: 0;
}

.page-about .about-ring__seg--b {
  stroke: var(--green);
  stroke-dasharray: 120.4 326.7;
  stroke-dashoffset: -137.6;
}

.page-about .about-ring__seg--c {
  stroke: var(--accent-warm);
  stroke-dasharray: 68.8 326.7;
  stroke-dashoffset: -258;
}

.page-about .about-ring__center {
  position: absolute;
  inset: 0;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 2px;
  pointer-events: none;
}

.page-about .about-ring__total {
  font-size: clamp(30px, 6vw, 42px);
  line-height: 1;
  color: var(--ice);
  font-weight: 600;
}

.page-about .about-ring__unit {
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--muted);
}

.page-about .about-ring__legend {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--rule-faint);
}

.page-about .about-ring__key {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 10px;
  padding: 12px 0;
  border-bottom: var(--rule-faint);
}

.page-about .about-ring__dot {
  width: 9px;
  height: 9px;
  background: var(--accent);
}

.page-about .about-ring__key--b .about-ring__dot {
  background: var(--green);
}

.page-about .about-ring__key--c .about-ring__dot {
  background: var(--accent-warm);
}

.page-about .about-ring__name {
  font-size: 14px;
  color: var(--text-soft);
}

.page-about .about-ring__value {
  font-size: 17px;
  color: var(--ice);
}

.page-about .about-network h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 15.5px;
  letter-spacing: .04em;
  color: var(--accent);
}

.page-about .about-network p {
  margin: 0 0 20px;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-soft);
  max-width: 46em;
}

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

/* ---------- 资质 ---------- */
.page-about .about-assure {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: var(--rule);
}

.page-about .about-assure__item {
  background: var(--bg);
  padding: clamp(16px, 2.4vw, 24px);
  display: grid;
  gap: 8px;
  align-content: start;
}

.page-about .about-assure__item .tag {
  justify-self: start;
}

.page-about .about-assure h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: .035em;
  color: var(--ice);
}

.page-about .about-assure p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--text-soft);
}

.page-about .about-note {
  margin-top: clamp(22px, 3vw, 30px);
  padding: clamp(16px, 2.4vw, 24px);
  border: var(--rule-faint);
  background:
    repeating-linear-gradient(135deg, rgba(30, 78, 102, .16) 0 1px, transparent 1px 10px),
    rgba(8, 32, 49, .7);
}

.page-about .about-note p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-soft);
  max-width: 52em;
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  border-top: var(--rule);
  background: linear-gradient(180deg, rgba(12, 42, 61, .55), transparent 70%);
  padding: clamp(32px, 5vw, 64px) 0 clamp(40px, 6vw, 80px);
}

.page-about .about-next__grid {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
}

.page-about .about-next h2 {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.3rem, 2.8vw, 1.9rem);
  line-height: 1.3;
  letter-spacing: .035em;
  color: var(--ice);
  max-width: 16em;
}

.page-about .about-next__links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-next__links a {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 6px 16px;
  padding: 14px 16px;
  border: var(--rule-soft);
  background: rgba(6, 24, 38, .6);
  color: var(--text-soft);
  font-size: 14.5px;
  text-decoration: none;
  transition: border-color .2s ease, background .2s ease, color .2s ease;
}

.page-about .about-next__links a .mono {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--accent);
}

.page-about .about-next__links a:hover,
.page-about .about-next__links a:focus-visible {
  border-color: var(--accent);
  background: rgba(31, 224, 207, .09);
  color: var(--ice);
  outline: none;
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .pipe {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-about .about-defs__row {
    grid-template-columns: minmax(0, 14em) minmax(0, 1fr);
    gap: 8px 24px;
    align-items: baseline;
  }

  .page-about .about-band__track {
    grid-auto-flow: row;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    overflow-x: visible;
  }

  .page-about .about-band__item:nth-child(odd) {
    border-left: 0;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .about-brief {
    margin-top: 8px;
  }

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

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

  .page-about .about-band__item:nth-child(odd) {
    border-left: var(--rule-faint);
  }

  .page-about .about-band__item:first-child {
    border-left: 0;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  }

  .page-about .about-next__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

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

@media (min-width: 1040px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: 104px;
    border-right: var(--rule-faint);
    padding-right: 20px;
    align-self: start;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-index__list li {
    flex: 0 1 auto;
  }

  .page-about .about-index__list a {
    display: flex;
    width: 100%;
    border: 0;
    border-left: 1px solid var(--line);
    background: transparent;
    padding: 10px 0 10px 14px;
    font-size: 13.5px;
  }

  .page-about .about-index__list a:hover,
  .page-about .about-index__list a:focus-visible {
    border-left: 2px solid var(--accent);
    background: rgba(31, 224, 207, .09);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-ring__seg,
  .page-about .pipe__step,
  .page-about .timeline__toggle::before,
  .page-about .timeline__toggle::after,
  .page-about .about-index__list a,
  .page-about .about-next__links a {
    transition: none;
  }
}
<<<END>>>