.page-about {
  --ab-line: rgba(7, 26, 47, 0.14);
  --ab-body: #33414a;
  --ab-night: linear-gradient(165deg, #071a2f 0%, #0c2842 56%, #123350 100%);
  background: var(--frost);
  color: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(1rem, 2.5vw, 1.75rem) clamp(2rem, 5vw, 3.25rem);
  background:
    radial-gradient(115% 85% at 92% -16%, var(--ice-a22), transparent 62%),
    radial-gradient(95% 70% at -10% 108%, var(--cyan-a16), transparent 68%),
    var(--frost);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -16%;
  bottom: -130px;
  width: min(72%, 720px);
  height: 260px;
  background: linear-gradient(90deg, transparent, rgba(143, 216, 255, 0.32));
  transform: skewY(-6deg);
  pointer-events: none;
}

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

.page-about .about-hero-copy {
  margin-top: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-title {
  margin: 0.85rem 0 0;
  max-width: 21em;
  font-size: clamp(1.85rem, 5.4vw, 3.3rem);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.022em;
}

.page-about .about-lede {
  margin-top: 1.05rem;
  max-width: 58ch;
  color: var(--ab-body);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 1.55rem;
}

/* 章节索引 */
.page-about .about-index-nav {
  margin-top: clamp(2rem, 4.5vw, 2.75rem);
}

.page-about .about-index {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-index li {
  background: var(--frost);
}

.page-about .about-index a {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  padding: 0.85rem 0.9rem;
  text-decoration: none;
  color: var(--ink);
  transition: background var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}

.page-about .about-index a:hover,
.page-about .about-index a:focus-visible {
  background: rgba(32, 240, 208, 0.16);
  color: var(--deep);
}

.page-about .about-index-num {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.06em;
  color: var(--clay);
}

.page-about .about-index-label {
  font-size: 0.94rem;
  font-weight: 600;
}

/* 数据带 */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.1rem 1rem;
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
  padding-top: 1.35rem;
  border-top: 1px solid var(--ab-line);
}

.page-about .about-stats .stat-value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.3rem, 3.4vw, 1.85rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--deep);
}

.page-about .about-stats .stat-label {
  display: block;
  margin-top: 0.3rem;
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  color: var(--ab-body);
}

/* ---------- 章节通用 ---------- */
.page-about .about-chapter {
  position: relative;
  padding-block: clamp(2.25rem, 5vw, 4rem);
  scroll-margin-top: calc(var(--header-h) + 1.25rem);
}

.page-about .about-chapter--sand {
  background: var(--sand);
}

.page-about .about-chapter--night {
  background: var(--ab-night);
  color: var(--frost);
}

.page-about .about-chapter-inner {
  display: grid;
  gap: 1.1rem;
}

.page-about .about-chapter-head {
  display: flex;
  align-items: baseline;
  gap: 0.55rem;
}

.page-about .about-num {
  font-family: var(--font-mono);
  font-size: clamp(1.7rem, 4.6vw, 2.5rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--deep);
}

.page-about .about-kicker {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--moss);
}

.page-about .about-chapter--night .about-num {
  color: var(--cyan);
}

.page-about .about-chapter--night .about-kicker {
  color: rgba(143, 216, 255, 0.78);
}

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

.page-about .about-chapter-body > h2 {
  margin: 0 0 0.85rem;
  max-width: 20em;
  font-size: clamp(1.35rem, 3.2vw, 2rem);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: -0.012em;
}

.page-about .about-chapter-body > p {
  margin: 0 0 0.95rem;
  max-width: 64ch;
  line-height: 1.85;
  color: var(--ab-body);
}

.page-about .about-chapter--night .about-chapter-body > p {
  color: rgba(244, 250, 255, 0.8);
}

/* 图片 */
.page-about .about-figure {
  margin: 1.6rem 0 0;
}

.page-about .about-figure .media-frame {
  overflow: hidden;
  border-radius: var(--r-md);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--r-md);
}

.page-about .about-figure .media-caption {
  margin-top: 0.55rem;
}

/* 引用块 */
.page-about .about-quote {
  margin: 1.6rem 0 0;
  max-width: 56ch;
  padding: 1.15rem 1.15rem 1.15rem 1.3rem;
  background: var(--sand);
  border-left: 4px solid var(--ice);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--deep);
}

/* 流程 */
.page-about .about-flow {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  border-top: 1px solid var(--ab-line);
}

.page-about .about-flow li {
  display: grid;
  grid-template-columns: 2.3rem minmax(0, 1fr);
  gap: 0.85rem;
  padding: 1.05rem 0;
  border-bottom: 1px solid var(--ab-line);
}

.page-about .about-flow-num {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  color: var(--clay);
  padding-top: 0.18rem;
}

.page-about .about-flow h3 {
  margin: 0 0 0.32rem;
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--deep);
}

.page-about .about-flow p {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--ab-body);
}

.page-about .about-afterword {
  margin-top: 1.25rem;
  padding: 0.85rem 1rem;
  border-left: 3px solid var(--cyan);
  background: rgba(32, 240, 208, 0.12);
  font-size: 0.94rem;
  line-height: 1.8;
  color: var(--deep);
}

/* 团队数据格 */
.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 1.6rem;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-fact {
  background: var(--frost);
  padding: 0.95rem 0.9rem;
}

.page-about .about-fact-value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.3rem, 3.6vw, 1.75rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--deep);
}

.page-about .about-fact-label {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.78rem;
  line-height: 1.6;
  color: var(--ab-body);
}

/* ---------- 里程碑 ---------- */
.page-about .about-milestones {
  position: relative;
  list-style: none;
  margin: 1.7rem 0 0;
  padding: 0 0 0 2rem;
}

.page-about .about-milestones::before {
  content: "";
  position: absolute;
  left: 0.5rem;
  top: 0.45rem;
  bottom: 0.6rem;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), rgba(143, 216, 255, 0.14));
}

.page-about .about-milestone {
  position: relative;
  padding-bottom: 1.7rem;
  scroll-margin-top: calc(var(--header-h) + 1rem);
}

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

.page-about .about-milestone::before {
  content: "";
  position: absolute;
  left: -1.9rem;
  top: 0.4rem;
  width: 0.8rem;
  height: 0.8rem;
  border-radius: 50%;
  background: var(--deep);
  box-shadow: 0 0 0 3px var(--cyan);
  transition: background var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease);
}

.page-about .about-milestone:hover::before,
.page-about .about-milestone:focus-within::before {
  background: var(--orange);
  box-shadow: 0 0 0 3px var(--cyan);
}

.page-about .about-milestone:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}

.page-about .about-ms-version {
  margin: 0;
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--ice);
}

.page-about .about-milestone h3 {
  margin: 0.3rem 0 0.35rem;
  font-size: 1.08rem;
  font-weight: 700;
  color: var(--frost);
}

.page-about .about-milestone p {
  margin: 0;
  max-width: 56ch;
  font-size: 0.94rem;
  line-height: 1.8;
  color: rgba(244, 250, 255, 0.76);
}

.page-about .about-ms-tag {
  display: inline-block;
  margin-top: 0.55rem;
  padding: 0.2rem 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--deep);
  background: var(--cyan);
  border-radius: var(--r-sm);
  opacity: 0;
  transform: translateY(-3px);
  transition: opacity var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease);
}

.page-about .about-milestone:hover .about-ms-tag,
.page-about .about-milestone:focus-within .about-ms-tag,
.page-about .about-milestone:focus .about-ms-tag {
  opacity: 1;
  transform: none;
}

/* ---------- 服务与联络 ---------- */
.page-about .about-contact {
  list-style: none;
  margin: 1.55rem 0 0;
  padding: 0;
  border-top: 1px solid var(--ab-line);
}

.page-about .about-contact li {
  display: grid;
  gap: 0.2rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--ab-line);
}

.page-about .about-c-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--moss);
}

.page-about .about-c-value {
  font-size: 0.98rem;
  line-height: 1.7;
  color: var(--deep);
}

.page-about .about-c-value--mono {
  font-family: var(--font-mono);
  letter-spacing: 0.01em;
  word-break: break-word;
}

.page-about .about-note {
  margin: 1.3rem 0 0;
  max-width: 60ch;
  font-size: 0.88rem;
  line-height: 1.85;
  color: var(--ab-body);
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 1.5rem;
}

/* ---------- 断点 ---------- */
@media (min-width: 620px) {
  .page-about .about-index {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 800px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-index {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .about-chapter-inner {
    grid-template-columns: 172px minmax(0, 1fr);
    gap: clamp(1.5rem, 4vw, 3.25rem);
    align-items: start;
  }

  .page-about .about-chapter-head {
    position: sticky;
    top: calc(var(--header-h) + 2.25rem);
    flex-direction: column;
    gap: 0.45rem;
  }

  .page-about .about-chapter-head::after {
    content: "";
    width: 34px;
    height: 2px;
    margin-top: 0.35rem;
    background: var(--ice);
  }

  .page-about .about-chapter--night .about-chapter-head::after {
    background: var(--cyan);
  }

  .page-about .about-contact li {
    grid-template-columns: 8.5rem minmax(0, 1fr);
    align-items: baseline;
    gap: 1rem;
  }
}

@media (min-width: 1100px) {
  .page-about .about-chapter-inner {
    grid-template-columns: 196px minmax(0, 1fr);
  }
}

@media (hover: none) {
  .page-about .about-ms-tag {
    opacity: 1;
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index a,
  .page-about .about-ms-tag,
  .page-about .about-milestone::before {
    transition: none;
  }

  .page-about .about-ms-tag {
    transform: none;
  }
}
<<<END>>>