.page-about {
  background: var(--ink-deep);
  color: var(--text-on-ink);
}

.page-about a {
  color: var(--electric);
}

/* ---------- 首屏 ---------- */

.about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: calc(var(--header-h) + 32px) 0 48px;
}

.about-hero__deco {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.about-hero__tri {
  position: absolute;
  display: block;
}

.about-hero__tri--a {
  top: -12%;
  right: -14%;
  width: 76%;
  height: 86%;
  background: linear-gradient(140deg, var(--ink-layer), rgba(14, 44, 71, 0) 78%);
  clip-path: polygon(18% 0, 100% 0, 100% 100%, 0 68%);
}

.about-hero__tri--b {
  bottom: -8%;
  left: -16%;
  width: 54%;
  height: 58%;
  background: var(--neon);
  opacity: 0.08;
  clip-path: polygon(0 22%, 100% 0, 86% 100%, 0 86%);
}

.about-hero__tri--c {
  top: 16%;
  right: 4%;
  width: 96px;
  height: 96px;
  background: var(--coral);
  opacity: 0.18;
  clip-path: polygon(0 0, 100% 0, 0 100%);
}

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

.about-hero__crumb {
  margin-bottom: 24px;
}

.about-hero__crumb a {
  color: var(--text-on-ink-dim);
}

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

.about-hero__label {
  color: var(--neon);
}

.about-hero__title {
  margin: 12px 0 16px;
  font-size: clamp(30px, 7vw, 72px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.02em;
  max-width: 20ch;
}

.about-hero__lead {
  max-width: 56ch;
  color: var(--text-on-ink);
  font-size: 16px;
  line-height: 1.75;
}

.about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.about-hero__stats li {
  background: var(--ink-deep);
  padding: 14px 16px;
}

.about-hero__num {
  display: block;
  font-size: clamp(26px, 5vw, 40px);
  font-weight: 800;
  line-height: 1;
  color: var(--neon);
  letter-spacing: -0.02em;
}

.about-hero__key {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  color: var(--text-on-ink-dim);
}

.about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

/* ---------- 章节索引 ---------- */

.about-index {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: rgba(6, 24, 43, 0.92);
}

.about-index__inner {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-top: 12px;
  padding-bottom: 12px;
  overflow-x: auto;
  scrollbar-width: none;
}

.about-index__inner::-webkit-scrollbar {
  display: none;
}

.about-index__label {
  flex: none;
  color: var(--mist);
}

.about-index ul {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  white-space: nowrap;
}

.about-index a {
  display: inline-block;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--text-on-ink-dim);
  font-size: 13px;
  text-decoration: none;
  transition: color 180ms ease, border-color 180ms ease;
}

.about-index a:hover,
.about-index a:focus-visible {
  color: var(--neon);
  border-color: var(--neon);
}

/* ---------- 通用区块 ---------- */

.about-sec {
  padding: 56px 0;
}

.about-sec__head {
  max-width: 62ch;
  margin-bottom: 32px;
}

.about-sec__head h2 {
  margin: 10px 0 14px;
  font-size: clamp(28px, 4.6vw, 52px);
  font-weight: 300;
  line-height: 1.14;
  letter-spacing: -0.01em;
}

.about-sec__intro {
  max-width: 58ch;
  margin: 0;
  color: var(--text-on-ink-dim);
  font-size: 15px;
  line-height: 1.75;
}

.about-sec__head--narrow {
  max-width: 52ch;
}

.about-figure {
  position: relative;
  display: block;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-layer);
  aspect-ratio: 16 / 9;
}

.about-figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.about-figure--wide {
  aspect-ratio: 3 / 2;
}

.about-figure--3x2 {
  aspect-ratio: 3 / 2;
}

.about-figure--16x9 {
  aspect-ratio: 16 / 9;
}

/* ---------- 沿革 ---------- */

.about-history__figure {
  margin-bottom: 28px;
}

.about-axis {
  display: block;
  width: 100%;
  height: auto;
  margin-bottom: 24px;
  opacity: 0.9;
}

.about-track {
  display: grid;
  gap: 20px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.about-node {
  position: relative;
  padding: 22px 22px 22px 26px;
  background: var(--paper);
  color: var(--ink-black);
  border: 1px solid var(--ink-black);
  border-radius: var(--radius);
}

.about-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 22px;
  width: 3px;
  height: 30px;
  background: var(--neon);
}

.about-node__no {
  color: var(--link-on-paper);
}

.about-node h3 {
  margin: 10px 0 10px;
  font-size: 20px;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

.about-node p {
  margin: 0 0 8px;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(10, 22, 34, 0.78);
}

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

/* ---------- 横向数据带 ---------- */

.about-band {
  padding: 32px 0;
}

.about-band__list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
  margin: 0;
}

.about-band__item {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.about-band__item:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.about-band__num {
  flex: none;
  font-size: clamp(30px, 6vw, 48px);
  font-weight: 800;
  line-height: 1;
  color: var(--neon);
  letter-spacing: -0.02em;
}

.about-band__num--coral {
  color: var(--coral);
}

.about-band__item dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-on-ink);
}

.about-band__unit {
  display: inline-block;
  margin-right: 6px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--mist);
}

/* ---------- 内容分类 ---------- */

.about-cats__layout {
  display: grid;
  gap: 24px;
}

.about-cats__figure {
  aspect-ratio: 3 / 2;
}

.about-cats__list {
  display: grid;
  gap: 10px;
  align-content: start;
}

.about-cat .expand-btn {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  padding: 16px 18px;
  background: var(--ink-layer);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--text-on-ink);
  text-align: left;
  cursor: pointer;
  transition: border-color 180ms ease, background-color 180ms ease;
}

.about-cat .expand-btn:hover,
.about-cat .expand-btn:focus-visible {
  border-color: var(--coral);
  background: rgba(255, 122, 69, 0.06);
}

.about-cat__name {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.about-cat__freq {
  margin-left: auto;
  color: var(--mist);
  white-space: nowrap;
}

.about-cat .expand-body {
  border: 1px solid var(--line);
  border-top: 0;
  border-radius: 0 0 var(--radius) var(--radius);
}

.about-cat .expand-inner p {
  margin: 0 0 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-on-ink-dim);
}

.about-cat .expand-inner p:last-child {
  margin-bottom: 0;
}

/* ---------- 团队 ---------- */

.about-split {
  display: grid;
  gap: 28px;
}

.about-split__body h2 {
  margin: 10px 0 16px;
  font-size: clamp(26px, 4.4vw, 46px);
  font-weight: 300;
  line-height: 1.16;
  letter-spacing: -0.01em;
}

.about-split__figure {
  aspect-ratio: 3 / 2;
}

.about-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.about-facts li {
  background: var(--ink-deep);
  padding: 14px 12px;
}

.about-facts__num {
  display: block;
  font-size: clamp(22px, 4vw, 32px);
  font-weight: 800;
  line-height: 1;
  color: var(--neon);
}

.about-facts__key {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-on-ink-dim);
}

/* ---------- 版本对照 ---------- */

.about-steps {
  counter-reset: about-step;
  display: grid;
  gap: 18px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.about-steps li {
  position: relative;
  padding-left: 44px;
}

.about-steps li::before {
  counter-increment: about-step;
  content: counter(about-step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 1px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--coral);
  letter-spacing: 0.06em;
}

.about-steps h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
}

.about-steps p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-on-ink-dim);
}

.about-version__more {
  margin: 28px 0 0;
}

/* ---------- 纠错 ---------- */

.about-qa {
  display: grid;
  gap: 10px;
  max-width: 780px;
}

.about-qa .expand-btn {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  padding: 16px 18px;
  background: rgba(14, 44, 71, 0.55);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--text-on-ink);
  font-size: 15px;
  text-align: left;
  cursor: pointer;
  transition: border-color 180ms ease, color 180ms ease;
}

.about-qa .expand-btn:hover,
.about-qa .expand-btn:focus-visible {
  border-color: var(--neon);
  color: var(--neon);
}

.about-qa .expand-btn > span:first-child {
  flex: 1;
}

.about-qa .expand-body {
  border: 1px solid var(--line);
  border-top: 0;
  border-radius: 0 0 var(--radius) var(--radius);
  background: var(--ink-layer);
}

.about-qa .expand-inner p {
  margin: 0 0 8px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-on-ink-dim);
}

.about-qa .expand-inner p:last-child {
  margin-bottom: 0;
}

/* ---------- 页尾跳转 ---------- */

.about-next {
  padding: 40px 0 64px;
  border-top: 1px solid var(--line);
}

.about-next__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px;
}

.about-next__title {
  margin: 0;
  font-size: clamp(22px, 3.2vw, 30px);
  font-weight: 300;
  letter-spacing: -0.01em;
}

.about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-left: auto;
}

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .about-hero {
    padding: calc(var(--header-h) + 56px) 0 72px;
  }

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

  .about-band__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 32px;
  }

  .about-band__item {
    display: block;
    padding-bottom: 0;
    border-bottom: 0;
  }

  .about-band__num {
    display: block;
    margin-bottom: 10px;
  }
}

@media (min-width: 900px) {
  .about-sec {
    padding: 88px 0;
  }

  .about-track {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 36px;
    row-gap: 28px;
  }

  .about-node:nth-child(odd) {
    grid-column: 1;
  }

  .about-node:nth-child(even) {
    grid-column: 2;
  }

  .about-cats__layout {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 36px;
    align-items: start;
  }

  .about-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 44px;
    align-items: start;
  }

  .about-split--flip .about-split__body {
    order: 1;
  }

  .about-split--flip .about-split__figure {
    order: 0;
  }
}

@media (min-width: 1100px) {
  .about-hero__title {
    max-width: 18ch;
  }
}
<<<END>>>