.page-about {
  --about-line: rgba(140, 166, 184, 0.18);
  --about-line-cyan: rgba(0, 229, 208, 0.34);
  --about-warm-ink: #a8390f;
  position: relative;
  padding: clamp(18px, 3vw, 34px) 0 clamp(56px, 8vw, 104px);
  background-color: var(--ink-deep);
  background-image:
    radial-gradient(900px 520px at 92% -8%, rgba(0, 229, 208, 0.16), transparent 62%),
    radial-gradient(760px 480px at -8% 40%, rgba(255, 122, 47, 0.12), transparent 60%),
    linear-gradient(180deg, rgba(12, 34, 51, 0.72), transparent 30%);
  color: var(--cold-white);
  font-family: var(--font-body);
  overflow-x: clip;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(140, 166, 184, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(140, 166, 184, 0.055) 1px, transparent 1px);
  background-size: 72px 72px;
  z-index: 0;
}

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

.page-about .label {
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--mist);
  margin: 0;
}

.page-about a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 229, 208, 0.4);
  transition: color var(--dur) ease, border-color var(--dur) ease;
}

.page-about a:hover {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

.page-about a:focus-visible,
.page-about button:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
  border-radius: 4px;
}

/* 面包屑 */
.page-about .breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: clamp(22px, 3.4vw, 34px);
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.page-about .breadcrumbs a {
  color: var(--mist);
  border-bottom-color: transparent;
}

.page-about .breadcrumbs a:hover {
  color: var(--cyan);
}

.page-about .breadcrumbs__sep {
  color: var(--ink-steel);
}

.page-about .breadcrumbs__current {
  color: var(--cold-white);
}

/* 首屏 */
.page-about .about-hero {
  display: grid;
  gap: 16px;
  padding-bottom: clamp(26px, 4vw, 44px);
  border-bottom: 1px solid var(--about-line);
}

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

.page-about .about-hero h1 {
  margin: 0;
  font-family: var(--font-editorial);
  font-size: clamp(32px, 6.4vw, 64px);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: 0.01em;
  max-width: 15ch;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 36em;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.9;
  color: rgba(233, 245, 250, 0.78);
}

/* 布局与索引轨 */
.page-about .about-layout {
  display: grid;
  gap: clamp(22px, 3vw, 32px);
  margin-top: clamp(24px, 4vw, 42px);
}

.page-about .about-rail {
  padding-top: 12px;
  border-top: 1px solid var(--about-line);
}

.page-about .about-rail__head {
  display: none;
  margin-bottom: 10px;
}

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

.page-about .about-rail__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid rgba(140, 166, 184, 0.28);
  border-radius: var(--radius-pill);
  color: var(--mist);
  font-size: 13px;
  white-space: nowrap;
  border-bottom-color: rgba(140, 166, 184, 0.28);
  transition: color var(--dur) ease, border-color var(--dur) ease, background-color var(--dur) ease;
}

.page-about .about-rail__link .num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--cyan);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--cold-white);
  border-color: var(--cyan);
  background-color: rgba(0, 229, 208, 0.08);
}

.page-about .about-body {
  min-width: 0;
}

/* 章节结构 */
.page-about .about-sec {
  padding: clamp(30px, 4.6vw, 58px) 0;
  border-top: 1px solid var(--about-line);
}

.page-about .about-sec:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-sec__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px 18px;
  align-items: start;
  margin-bottom: clamp(18px, 2.6vw, 26px);
}

.page-about .about-sec__num {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(40px, 7.4vw, 72px);
  line-height: 0.78;
  letter-spacing: -0.03em;
  color: rgba(0, 229, 208, 0.26);
  font-variant-numeric: tabular-nums;
}

@supports (-webkit-text-stroke: 1px #000) {
  .page-about .about-sec__num {
    color: transparent;
    -webkit-text-stroke: 1px rgba(0, 229, 208, 0.55);
  }
}

.page-about .about-sec__title {
  display: grid;
  gap: 8px;
  align-content: start;
  padding-top: 6px;
  min-width: 0;
}

.page-about .about-sec__title h2 {
  margin: 0;
  font-family: var(--font-editorial);
  font-size: clamp(22px, 3.4vw, 38px);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: 0.01em;
}

.page-about .about-text {
  max-width: 36em;
}

.page-about .about-text p {
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(233, 245, 250, 0.8);
}

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

/* 关键数字 */
.page-about .about-stats {
  display: grid;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .about-stat {
  display: grid;
  grid-template-columns: minmax(88px, auto) minmax(0, 1fr);
  gap: 6px 18px;
  align-items: baseline;
  padding: 16px 0;
  border-top: 1px solid var(--about-line);
}

.page-about .about-stat:last-child {
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(28px, 5.4vw, 46px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.page-about .about-stat__num--cyan {
  color: var(--cyan);
}

.page-about .about-stat__num--white {
  color: var(--cold-white);
}

.page-about .about-stat__label {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-stat__label strong {
  display: block;
  margin-bottom: 2px;
  font-size: 15px;
  font-weight: 500;
  color: var(--cold-white);
}

/* 图片 */
.page-about .about-figure {
  margin: 0 0 clamp(20px, 3vw, 28px);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: 18px;
  border: 1px solid rgba(0, 229, 208, 0.22);
  background-color: var(--ink-panel);
}

.page-about .about-figure--tall img {
  max-height: 520px;
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

/* 四道工序 */
.page-about .about-flow {
  display: grid;
  gap: 0;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-flow__step {
  position: relative;
  padding: 0 0 24px 22px;
  border-left: 1px solid var(--about-line-cyan);
}

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

.page-about .about-flow__step::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 4px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background-color: var(--cyan);
  box-shadow: 0 0 0 4px rgba(0, 229, 208, 0.14);
}

.page-about .about-flow__step:last-child::before {
  background-color: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 122, 47, 0.16);
}

.page-about .about-flow__k {
  display: block;
  margin-bottom: 5px;
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-flow__step h3 {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 600;
  color: var(--cold-white);
}

.page-about .about-flow__step p {
  margin: 0;
  max-width: 30em;
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist);
}

/* 团队 */
.page-about .about-crew {
  display: grid;
  gap: clamp(18px, 3vw, 26px);
  margin-top: clamp(18px, 3vw, 26px);
}

.page-about .about-crew__total {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--about-line-cyan);
}

.page-about .about-crew__num {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(48px, 9vw, 82px);
  line-height: 0.86;
  letter-spacing: -0.03em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

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

.page-about .about-crew__list li {
  padding: 14px 0;
  border-top: 1px solid var(--about-line);
}

.page-about .about-crew__list li:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-crew__role {
  font-size: 16px;
  font-weight: 500;
  color: var(--cold-white);
}

.page-about .about-crew__count {
  margin-left: 8px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .about-crew__list p {
  margin: 6px 0 0;
  max-width: 32em;
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist);
}

/* 时间轴 */
.page-about .about-tl {
  position: relative;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 12px;
  width: 1px;
  background-image: linear-gradient(180deg, rgba(0, 229, 208, 0.7), rgba(0, 229, 208, 0.08));
}

.page-about .about-tl__item {
  position: relative;
  padding-bottom: clamp(22px, 3vw, 30px);
}

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

.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 8px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background-color: var(--amber);
  box-shadow: 0 0 0 4px rgba(255, 194, 75, 0.13);
}

.page-about .about-tl__when {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .about-tl__item h3 {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 600;
  color: var(--cold-white);
}

.page-about .about-tl__item p {
  margin: 0;
  max-width: 32em;
  font-size: 14px;
  line-height: 1.74;
  color: var(--mist);
}

/* 版本对照 */
.page-about .about-ver {
  display: grid;
  gap: 16px;
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .about-ver__panel {
  padding: 22px 20px;
  background-color: var(--ink-panel);
  border: 1px solid rgba(140, 166, 184, 0.22);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
  transition: background-color var(--dur) ease, border-color var(--dur) ease;
}

.page-about .about-ver__panel--orange {
  border-color: rgba(255, 122, 47, 0.55);
}

.page-about .about-ver__panel--cyan {
  border-color: rgba(0, 229, 208, 0.5);
}

.page-about .about-ver__panel:hover {
  background-color: var(--ink-steel);
}

.page-about .about-ver__panel h3 {
  margin: 8px 0 8px;
  font-family: var(--font-editorial);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--cold-white);
}

.page-about .about-ver__panel > p {
  margin: 0;
  max-width: 30em;
  font-size: 14px;
  line-height: 1.76;
  color: var(--mist);
}

.page-about .about-ver__panel details {
  margin-top: 14px;
  padding-top: 10px;
  border-top: 1px dashed rgba(140, 166, 184, 0.32);
}

.page-about .about-ver__panel summary {
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  list-style: none;
}

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

.page-about .about-ver__panel summary::after {
  content: "+";
  font-family: var(--font-mono);
}

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

.page-about .about-ver__panel details p {
  margin: 8px 0 0;
  max-width: 30em;
  font-size: 13px;
  line-height: 1.72;
  color: var(--mist);
}

/* 合作纸卡 */
.page-about .paper-card {
  margin-top: clamp(18px, 3vw, 26px);
  padding: clamp(22px, 3.4vw, 36px);
  background-color: var(--paper);
  color: var(--paper-ink);
  border-radius: var(--radius-lg);
}

.page-about .about-coop p {
  margin: 0 0 14px;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(34, 26, 20, 0.82);
}

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

.page-about .about-coop a {
  color: var(--about-warm-ink);
  border-bottom-color: rgba(168, 57, 15, 0.45);
}

.page-about .about-coop__list {
  display: grid;
  gap: 10px;
  margin: 18px 0;
  padding: 0;
  list-style: none;
}

.page-about .about-coop__list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(34, 26, 20, 0.14);
  font-size: 14px;
  line-height: 1.7;
  color: rgba(34, 26, 20, 0.78);
}

.page-about .about-coop__n {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 22px;
  line-height: 1;
  color: var(--about-warm-ink);
  font-variant-numeric: tabular-nums;
}

/* 双折入口 */
.page-about .about-gate {
  display: grid;
  gap: 14px;
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .about-gate .gate__panel {
  display: block;
  padding: 22px 20px;
  background-color: var(--ink-panel);
  border: 1px solid rgba(140, 166, 184, 0.22);
  border-radius: 18px;
  color: var(--cold-white);
  transition: background-color var(--dur) ease, border-color var(--dur) ease, transform var(--dur) ease;
}

.page-about .about-gate .gate__panel--cyan {
  border-color: rgba(0, 229, 208, 0.45);
}

.page-about .about-gate .gate__panel--orange {
  border-color: rgba(255, 122, 47, 0.5);
}

.page-about .about-gate .gate__panel:hover {
  background-color: var(--ink-steel);
  transform: translateY(-2px);
}

.page-about .about-gate .gate__panel .label {
  color: var(--mist);
}

.page-about .about-gate .gate__panel--cyan .label {
  color: var(--cyan);
}

.page-about .about-gate .gate__panel--orange .label {
  color: var(--orange);
}

.page-about .about-gate h3 {
  margin: 10px 0 6px;
  font-family: var(--font-editorial);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--cold-white);
}

.page-about .about-gate p {
  margin: 0;
  max-width: 30em;
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist);
}

/* 联系条 */
.page-about .about-contact {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 18px;
  margin-top: clamp(22px, 3vw, 30px);
  padding-top: 18px;
  border-top: 1px solid var(--about-line);
}

.page-about .about-contact p {
  flex: 1 1 240px;
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid rgba(0, 229, 208, 0.5);
  border-radius: var(--radius-pill);
  background-color: transparent;
  color: var(--cyan);
  font-family: var(--font-body);
  font-size: 14px;
  cursor: pointer;
  transition: background-color var(--dur) ease, color var(--dur) ease, border-color var(--dur) ease;
}

.page-about .copy-btn:hover {
  background-color: rgba(0, 229, 208, 0.12);
  border-color: var(--cyan);
  color: var(--cyan-soft);
}

.page-about .copy-btn[data-copied] {
  border-color: var(--orange);
  color: var(--orange);
}

.page-about .about-contact__back {
  font-size: 14px;
}

/* 平板与桌面 */
@media (min-width: 800px) {
  .page-about .about-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-flow__step {
    padding: 24px 18px 0 0;
    border-left: 0;
    border-top: 1px solid var(--about-line-cyan);
  }

  .page-about .about-flow__step:last-child {
    padding-right: 0;
  }

  .page-about .about-flow__step::before {
    left: 0;
    top: -5px;
  }

  .page-about .about-ver {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-gate {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-crew {
    grid-template-columns: 180px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-crew__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 32px;
  }

  .page-about .about-crew__list li:nth-child(2) {
    border-top: 0;
    padding-top: 0;
  }
}

@media (min-width: 900px) {
  .page-about .about-layout {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: clamp(36px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 24px;
    padding-top: 0;
    border-top: 0;
  }

  .page-about .about-rail__head {
    display: block;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 2px;
    padding: 0;
    overflow: visible;
  }

  .page-about .about-rail__link {
    padding: 8px 10px;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    font-size: 14px;
    white-space: normal;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--cyan);
    background-color: rgba(0, 229, 208, 0.06);
  }
}

@media (min-width: 1100px) {
  .page-about .about-sec--shift {
    margin-left: clamp(24px, 5vw, 72px);
  }
}

@media (max-width: 520px) {
  .page-about .about-stat {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
  }

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

  .page-about .about-figure--tall img {
    max-height: 360px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-gate .gate__panel:hover {
    transform: none;
  }

  .page-about a,
  .page-about .copy-btn,
  .page-about .about-ver__panel,
  .page-about .about-gate .gate__panel,
  .page-about .about-rail__link {
    transition: none;
  }
}
<<<END>>>