.page-about {
  --about-max: 1120px;
  --about-pad: 20px;
  background: var(--ink);
  color: var(--ice);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  overflow-x: hidden;
}

.page-about * {
  box-sizing: border-box;
}

.page-about .about-wrap {
  width: 100%;
  max-width: var(--about-max);
  margin: 0 auto;
  padding: 0 var(--about-pad);
}

.page-about [id] {
  scroll-margin-top: calc(var(--header-h) + 70px);
}

.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: calc(var(--header-h) + 32px) 0 48px;
  background:
    radial-gradient(circle at 84% 8%, rgba(56, 232, 216, 0.14), transparent 46%),
    linear-gradient(162deg, var(--teal) 0%, var(--ink) 62%);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -16%;
  right: -12%;
  width: 66%;
  height: 130%;
  background: linear-gradient(135deg, rgba(23, 21, 46, 0.92), rgba(23, 21, 46, 0) 72%);
  clip-path: polygon(24% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 32px;
}

.page-about .about-kicker {
  margin: 18px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(34px, 7.2vw, 66px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--ice);
}

.page-about .about-hero__lead {
  margin: 20px 0 0;
  max-width: 54ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .about-hero__stats {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-hero__stats li {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 16px 18px;
  background: rgba(7, 20, 31, 0.88);
}

.page-about .about-hero__stats .mono {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  line-height: 1.15;
  color: var(--amber);
}

.page-about .about-hero__stats em {
  font-style: normal;
  font-size: 13px;
  line-height: 1.6;
  color: var(--steel);
}

.page-about .about-hero__figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--indigo);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  max-height: 280px;
  object-fit: cover;
}

/* ---------- 章节跳转条 ---------- */

.page-about .about-jump {
  position: sticky;
  top: var(--header-h);
  z-index: 6;
  background: rgba(7, 20, 31, 0.94);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-jump__list {
  list-style: none;
  display: flex;
  align-items: stretch;
  gap: 0;
  overflow-x: auto;
  scrollbar-width: none;
  padding-top: 2px;
  padding-bottom: 2px;
}

.page-about .about-jump__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-jump__list li + li {
  margin-left: 18px;
}

.page-about .about-jump__list a {
  display: block;
  white-space: nowrap;
  padding: 12px 0;
  border-bottom: 2px solid transparent;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--steel);
  text-decoration: none;
  transition: color 0.18s, border-color 0.18s;
}

.page-about .about-jump__list a:hover,
.page-about .about-jump__list a:focus-visible {
  color: var(--ice);
  border-bottom-color: var(--amber);
}

/* ---------- 区块通用 ---------- */

.page-about .about-section {
  padding: 56px 0;
}

.page-about .about-section--teal {
  background: var(--teal);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-section--indigo {
  background: var(--indigo);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-section--numbers {
  background:
    repeating-linear-gradient(115deg, rgba(44, 74, 85, 0.22) 0 1px, transparent 1px 30px),
    var(--ink-soft);
}

.page-about .about-section--bookmark {
  background:
    repeating-linear-gradient(115deg, rgba(56, 232, 216, 0.05) 0 1px, transparent 1px 26px),
    linear-gradient(180deg, var(--ink) 0%, var(--teal) 100%);
  border-top: 1px solid var(--line);
}

.page-about .about-head {
  max-width: 760px;
}

.page-about .section-tag {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .section-tag__num {
  color: var(--amber);
  font-weight: 600;
}

.page-about .section-tag__line {
  flex: 1 1 auto;
  min-width: 28px;
  height: 1px;
  background: var(--line);
}

.page-about .about-h2 {
  margin: 18px 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(26px, 4.8vw, 44px);
  line-height: 1.14;
  letter-spacing: -0.015em;
  color: var(--ice);
}

.page-about .about-head__lead {
  margin: 16px 0 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--steel);
}

/* ---------- 01 品牌定位 ---------- */

.page-about .about-brand__body {
  display: grid;
  gap: 32px;
  margin-top: 30px;
}

.page-about .about-brand__text p {
  margin: 0 0 18px;
  max-width: 62ch;
  color: var(--ice);
}

.page-about .about-brand__text p:first-child {
  font-size: 18px;
  line-height: 1.8;
}

.page-about .about-brand__text p:last-child {
  margin-bottom: 0;
  color: var(--steel);
}

.page-about .about-who {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-who li {
  padding: 18px 20px;
  background: var(--ink-soft);
  border-left: 2px solid transparent;
  transition: border-color 0.18s;
}

.page-about .about-who li:hover {
  border-left-color: var(--cyan);
}

.page-about .about-who h3 {
  margin: 0 0 6px;
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--ice);
}

.page-about .about-who p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--steel);
}

/* ---------- 02 栏目体系 ---------- */

.page-about .about-columns {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-columns__item {
  display: grid;
  gap: 6px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-columns__idx {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .about-columns__title {
  margin: 0;
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--ice);
}

.page-about .about-columns__desc {
  margin: 8px 0 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--steel);
}

.page-about .about-columns__link {
  justify-self: start;
  padding-top: 2px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--amber);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s, border-color 0.18s;
}

.page-about .about-columns__link:hover,
.page-about .about-columns__link:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* ---------- 03 版本演进 ---------- */

.page-about .about-timeline {
  display: grid;
  gap: 30px;
  margin-top: 34px;
}

.page-about .about-timeline__figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--teal);
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 0 100%);
}

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

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

.page-about .about-stage:last-of-type {
  border-bottom: 1px solid var(--line);
}

.page-about .about-stage summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 16px 0;
  list-style: none;
  cursor: pointer;
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--ice);
  transition: color 0.18s;
}

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

.page-about .about-stage summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 600;
  color: var(--cyan);
}

.page-about .about-stage[open] summary {
  color: var(--amber);
}

.page-about .about-stage[open] summary::after {
  content: "–";
  color: var(--amber);
}

.page-about .about-stage__cycle {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  white-space: nowrap;
}

.page-about .about-stage__body {
  padding: 0 0 20px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--steel);
}

.page-about .about-stage__body p {
  margin: 0 0 12px;
  max-width: 60ch;
}

.page-about .about-stage__body ul {
  margin: 0;
  padding-left: 18px;
  display: grid;
  gap: 6px;
}

.page-about .about-versionnote {
  margin: 26px 0 0;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--amber);
  background: var(--ink-soft);
  font-size: 15px;
  line-height: 1.75;
  color: var(--steel);
}

.page-about .about-versionnote .mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--ice);
}

/* ---------- 04 团队协作 ---------- */

.page-about .about-team {
  display: grid;
  gap: 30px;
  margin-top: 34px;
}

.page-about .about-team__figure {
  margin: 0;
  border: 1px solid var(--line);
  background: rgba(7, 20, 31, 0.5);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

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

.page-about .about-team__cards {
  display: grid;
  gap: 14px;
}

.page-about .about-team__card {
  padding: 18px 20px;
  border: 1px solid var(--line);
  background: rgba(7, 20, 31, 0.55);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
}

.page-about .about-team__card h3 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 700;
  color: var(--amber);
}

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

.page-about .about-partners {
  margin: 24px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-size: 14px;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .about-partners strong {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

/* ---------- 05 运营数据 ---------- */

.page-about .about-numbers {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-numbers__item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 24px 20px;
  background: var(--ink);
}

.page-about .about-numbers__item:nth-child(even) {
  background: var(--teal);
}

.page-about .about-numbers__num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 4.6vw, 38px);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  line-height: 1;
  color: var(--amber);
}

.page-about .about-numbers__item:nth-child(2) .about-numbers__num {
  color: var(--cyan);
}

.page-about .about-numbers__item:nth-child(3) .about-numbers__num {
  color: var(--ice);
}

.page-about .about-numbers__label {
  font-size: 14px;
  line-height: 1.75;
  color: var(--steel);
}

/* ---------- 06 书签回访 ---------- */

.page-about .about-bookmark {
  display: grid;
  gap: 30px;
}

.page-about .about-book__text {
  margin: 18px 0 0;
  max-width: 52ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .about-steps {
  padding: 0 20px;
  border: 1px solid var(--line);
  background: rgba(7, 20, 31, 0.62);
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 0 100%);
}

.page-about .about-steps summary {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 18px 0;
  list-style: none;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--amber);
}

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

.page-about .about-steps summary::after {
  content: "→";
  margin-left: auto;
  color: var(--cyan);
  transition: transform 0.2s;
}

.page-about .about-steps[open] summary::after {
  transform: rotate(90deg);
}

.page-about .about-steps ol {
  list-style: none;
  counter-reset: aboutstep;
  margin: 0;
  padding: 0 0 22px;
  display: grid;
  gap: 16px;
}

.page-about .about-steps li {
  counter-increment: aboutstep;
  position: relative;
  padding-left: 42px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--steel);
}

.page-about .about-steps li::before {
  content: counter(aboutstep, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 1px;
  padding: 1px 5px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--cyan);
}

/* ---------- 响应式 ---------- */

@media (min-width: 600px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-hero__figure img {
    max-height: 320px;
  }
}

@media (min-width: 760px) {
  .page-about .about-columns__item {
    grid-template-columns: 56px minmax(0, 1fr) auto;
    align-items: start;
    column-gap: 20px;
  }

  .page-about .about-columns__idx {
    padding-top: 6px;
  }

  .page-about .about-columns__link {
    padding-top: 6px;
  }

  .page-about .about-team__cards {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-wrap {
    padding: 0 32px;
  }

  .page-about .about-hero {
    padding: calc(var(--header-h) + 56px) 0 72px;
  }

  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: end;
    gap: 48px;
  }

  .page-about .about-hero__figure {
    margin-bottom: 6px;
  }

  .page-about .about-hero__figure img {
    max-height: 420px;
  }

  .page-about .about-section {
    padding: 96px 0;
  }

  .page-about .about-brand__body {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.82fr);
    gap: 56px;
    margin-top: 44px;
  }

  .page-about .about-timeline {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    gap: 52px;
    margin-top: 44px;
    align-items: start;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 0.86fr) minmax(0, 1.14fr);
    gap: 52px;
    margin-top: 44px;
    align-items: start;
  }

  .page-about .about-numbers {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    margin-top: 44px;
  }

  .page-about .about-numbers__item {
    padding: 30px 22px;
  }

  .page-about .about-numbers__item:nth-child(1),
  .page-about .about-numbers__item:nth-child(3) {
    transform: translateY(14px);
  }

  .page-about .about-bookmark {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-steps {
    padding: 0 24px;
    margin-top: 8px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition: none !important;
    animation: none !important;
  }

  .page-about .about-numbers__item {
    transform: none !important;
  }
}
<<<END>>>