.page-about {
  --about-rail-w: 216px;
  --about-gap: clamp(26px, 4vw, 56px);
  background: var(--paper);
  color: var(--data-black);
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(130% 150% at 92% -10%, #10565A 0%, #0A3D3E 44%, #062A2B 100%);
  color: var(--paper);
  padding: clamp(18px, 3vw, 28px) 0 clamp(40px, 6vw, 76px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 6%;
  right: -10%;
  width: min(500px, 60vw);
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  border: 1px solid rgba(0, 229, 199, .22);
  box-shadow:
    0 0 0 30px rgba(0, 229, 199, .05),
    0 0 0 62px rgba(0, 229, 199, .03);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: -8%;
  bottom: -34%;
  width: 72%;
  height: 64%;
  background: linear-gradient(135deg, rgba(255, 122, 47, .18), rgba(255, 122, 47, 0));
  clip-path: polygon(0 0, 100% 34%, 100% 100%, 0 100%);
  pointer-events: none;
}

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

.page-about .about-hero .crumbs,
.page-about .about-hero .crumbs a {
  color: rgba(242, 250, 248, .7);
}

.page-about .about-hero .crumbs a:hover,
.page-about .about-hero .crumbs a:focus-visible {
  color: var(--neon);
}

.page-about .about-hero .crumb-sep {
  color: rgba(242, 250, 248, .38);
}

.page-about .about-kicker {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin: clamp(18px, 3vw, 30px) 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--field-teal);
}

.page-about .about-kicker::before {
  content: "";
  width: 22px;
  height: 2px;
  border-radius: var(--r-pill);
  background: var(--grad-data);
}

.page-about .about-kicker--light {
  color: var(--neon);
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  max-width: 20ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(29px, 5.4vw, 60px);
  line-height: 1.1;
  letter-spacing: -.02em;
  text-wrap: balance;
}

.page-about .about-hero__lead {
  margin: clamp(16px, 2.6vw, 26px) 0 0;
  max-width: 56ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.8;
  color: rgba(242, 250, 248, .84);
}

.page-about .about-stats {
  list-style: none;
  margin: clamp(26px, 4vw, 42px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .about-stats li {
  padding: 14px 16px;
  border-radius: var(--r-md);
  background: rgba(6, 42, 43, .5);
  border: 1px solid rgba(0, 229, 199, .2);
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-style: italic;
  font-weight: 700;
  font-size: clamp(24px, 3.2vw, 32px);
  line-height: 1;
  color: var(--neon);
}

.page-about .about-stat__unit {
  font-size: .55em;
  margin-left: 2px;
  font-style: normal;
}

.page-about .about-stat__k {
  display: block;
  margin-top: 9px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: rgba(242, 250, 248, .62);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  padding-top: clamp(30px, 5vw, 64px);
  padding-bottom: clamp(46px, 7vw, 96px);
}

.page-about .about-main {
  display: flex;
  flex-direction: column;
  gap: clamp(46px, 6vw, 92px);
  min-width: 0;
}

/* 左侧索引轴 */
.page-about .about-rail {
  display: none;
}

.page-about .about-rail__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--mist);
}

.page-about .about-rail__nav {
  display: flex;
  flex-direction: column;
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 12px;
  border-left: 2px solid var(--line);
  font-size: 14px;
  line-height: 1.4;
  color: var(--mist);
  text-decoration: none;
  transition: color .22s var(--ease-out), border-color .22s var(--ease-out);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--ink-deep);
  border-left-color: var(--field-teal);
}

.page-about .about-rail__link.is-active {
  border-left-color: var(--neon);
  color: var(--ink-deep);
  font-weight: 700;
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-style: italic;
  font-size: 12px;
  color: var(--field-teal);
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  min-width: 0;
}

.page-about .about-kicker {
  margin-top: 0;
}

.page-about .about-h2 {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(23px, 3.4vw, 36px);
  line-height: 1.2;
  letter-spacing: -.02em;
  color: var(--ink-deep);
}

.page-about .about-section p {
  margin: 14px 0 0;
  max-width: 38em;
  font-size: clamp(15px, 1.5vw, 16.5px);
  line-height: 1.8;
  color: var(--data-black);
}

.page-about .about-section a {
  color: var(--field-teal);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.page-about .about-section a:hover,
.page-about .about-section a:focus-visible {
  color: var(--ink-deep);
  text-decoration-color: var(--neon);
}

.page-about .about-more {
  padding-left: 14px;
  border-left: 3px solid var(--line);
  color: var(--mist);
  font-size: 14.5px;
}

/* ---------- 流程 ---------- */
.page-about .about-flow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 32px);
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .about-step {
  border-left: 3px solid var(--line);
  padding: 2px 0 2px 16px;
  margin-bottom: 14px;
  transition: border-color .22s var(--ease-out);
}

.page-about .about-step[open] {
  border-left-color: var(--neon);
}

.page-about .about-step > summary {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 6px 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16.5px;
  letter-spacing: -.01em;
  color: var(--ink-deep);
}

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

.page-about .about-step > summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 17px;
  color: var(--field-teal);
}

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

.page-about .about-step > summary:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 3px;
  border-radius: var(--r-sm);
}

.page-about .about-step__num {
  font-family: var(--font-mono);
  font-style: italic;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--neon);
  background: var(--ink-deep);
  border-radius: var(--r-pill);
  padding: 3px 9px;
}

.page-about .about-step__body p {
  margin-top: 8px;
  font-size: 15px;
  color: #24393a;
}

.page-about .about-flow__figure {
  margin: 0;
  max-width: 340px;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--ink-deep);
}

/* ---------- 团队 ---------- */
.page-about .about-team__figure {
  margin: clamp(22px, 3vw, 30px) 0 0;
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .about-roles {
  margin-top: clamp(20px, 3vw, 28px);
  gap: 14px;
}

.page-about .about-role {
  padding: 18px 18px 20px;
  border-radius: var(--r-md);
  background: #ffffff;
  border: 1px solid var(--line);
  border-top: 3px solid var(--field-teal);
}

.page-about .about-role__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  color: var(--ink-deep);
}

.page-about .about-role p {
  margin-top: 8px;
  font-size: 14.5px;
  line-height: 1.75;
  color: #2b4142;
}

/* ---------- 里程碑条带 ---------- */
.page-about .about-hint {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mist);
}

.page-about .about-hint::after {
  content: "→";
  color: var(--field-teal);
}

.page-about .about-timeline {
  list-style: none;
  display: flex;
  gap: 14px;
  margin: 14px 0 0;
  padding: 4px 0 18px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-timeline::-webkit-scrollbar {
  height: 6px;
}

.page-about .about-timeline::-webkit-scrollbar-thumb {
  background: var(--field-teal);
  border-radius: var(--r-pill);
}

.page-about .about-timeline::-webkit-scrollbar-track {
  background: var(--line);
  border-radius: var(--r-pill);
}

.page-about .about-mile {
  position: relative;
  flex: 0 0 min(78vw, 292px);
  scroll-snap-align: start;
  padding: 24px 20px 22px;
  border-radius: var(--r-md);
  background: #ffffff;
  border: 1px solid var(--line);
  box-shadow: var(--shadow-lift);
}

.page-about .about-mile::before {
  content: "";
  position: absolute;
  top: 0;
  left: 20px;
  right: 20px;
  height: 3px;
  border-radius: 0 0 var(--r-pill) var(--r-pill);
  background: var(--grad-data);
}

.page-about .about-mile__year {
  display: block;
  font-family: var(--font-mono);
  font-style: italic;
  font-weight: 700;
  font-size: 26px;
  line-height: 1;
  color: var(--ink-deep);
}

.page-about .about-mile__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15.5px;
  color: var(--field-teal);
}

.page-about .about-mile p {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.7;
  color: #2b4142;
}

/* ---------- 合作 ---------- */
.page-about .about-partner__figure {
  margin: clamp(22px, 3vw, 30px) 0 0;
  border-radius: var(--r-lg);
  overflow: hidden;
}

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

.page-about .about-rule {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
}

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

.page-about .about-rule dt {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  color: var(--ink-deep);
}

.page-about .about-rule__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: var(--r-pill);
  background: var(--ink-deep);
  color: var(--neon);
  font-family: var(--font-mono);
  font-style: italic;
  font-size: 12px;
}

.page-about .about-rule dd {
  margin: 0;
  padding-left: 36px;
  font-size: 15px;
  line-height: 1.8;
  color: #2b4142;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-rule {
    grid-template-columns: 190px minmax(0, 1fr);
    gap: 18px;
  }

  .page-about .about-rule dd {
    padding-left: 0;
  }
}

@media (min-width: 780px) {
  .page-about .about-flow {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    align-items: start;
  }

  .page-about .about-flow__figure {
    max-width: none;
    margin-top: 6px;
  }
}

@media (min-width: 960px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    column-gap: clamp(32px, 4vw, 72px);
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 104px;
    align-self: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .about-step {
    transition: none;
  }

  .page-about .about-timeline {
    scroll-behavior: auto;
  }
}
<<<END>>>