.page-about {
  --about-line: rgba(220, 233, 236, .18);
  --about-line-ink: rgba(10, 20, 24, .12);
  --about-soft: rgba(10, 20, 24, .05);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  background: var(--c-lake);
  color: var(--c-fog);
  padding-block: clamp(20px, 3.4vw, 36px) clamp(52px, 8vw, 104px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  z-index: 0;
  inset: -14% -20% auto auto;
  width: min(900px, 94%);
  height: 86%;
  background: linear-gradient(128deg, rgba(27, 79, 216, .62) 0%, rgba(57, 230, 122, .16) 55%, rgba(6, 42, 51, 0) 78%);
  clip-path: polygon(24% 0, 100% 0, 100% 74%, 0 100%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  z-index: 0;
  left: -10%;
  bottom: -34%;
  width: 60%;
  aspect-ratio: 1 / 1;
  background: radial-gradient(circle at 50% 50%, rgba(57, 230, 122, .16), rgba(6, 42, 51, 0) 68%);
  pointer-events: none;
}

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

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(26px, 3.6vw, 46px);
  margin-top: clamp(26px, 4vw, 54px);
}

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

.page-about .about-hero__title {
  margin: 0;
  font-size: clamp(36px, 7vw, 84px);
  line-height: 1.03;
  letter-spacing: -.03em;
  font-weight: 900;
  color: var(--c-paper);
  text-wrap: balance;
}

.page-about .about-hero__title em {
  font-style: normal;
  color: var(--c-turf);
}

.page-about .about-hero__lede {
  margin: clamp(18px, 2.4vw, 28px) 0 0;
  max-width: 36em;
  font-size: var(--fs-body);
  line-height: 1.78;
  color: var(--fog-86);
}

.page-about .about-hero__facts {
  display: grid;
  gap: 1px;
  margin: clamp(26px, 3.4vw, 42px) 0 0;
  padding: 0;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .about-hero__fact {
  background: rgba(11, 60, 73, .72);
  padding: 12px 14px;
}

.page-about .about-hero__fact dt {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--fog-64);
}

.page-about .about-hero__fact dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(17px, 2vw, 21px);
  font-variant-numeric: tabular-nums;
  color: var(--c-amber);
  letter-spacing: -.01em;
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, .94fr);
    align-items: end;
  }
}

@media (min-width: 620px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 图片容器 ---------- */
.page-about .about-figure {
  margin: 0;
  position: relative;
  min-width: 0;
  background: var(--c-night);
  border: 1px solid var(--about-line);
}

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

.page-about .about-figure figcaption {
  padding: 10px 13px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--fog-64);
  border-top: 1px solid var(--about-line);
}

.page-about .about-figure--rail {
  margin-top: clamp(30px, 4vw, 52px);
}

/* ---------- 章节索引条 ---------- */
.page-about .about-index {
  position: relative;
  z-index: 2;
  background: var(--c-mist);
  border-bottom: 1px solid var(--about-line-ink);
}

.page-about .about-index__inner {
  padding-block: 10px;
}

.page-about .about-index__list {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 4px 0 6px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .about-index__list li {
  flex: 0 0 auto;
}

.page-about .about-index__link {
  display: inline-block;
  white-space: nowrap;
  padding: 7px 13px;
  font-size: 14px;
  line-height: 1.4;
  color: var(--ink-78);
  text-decoration: none;
  background: var(--c-paper);
  border: 1px solid var(--about-line-ink);
  border-radius: var(--r);
  transition: color .2s ease, border-color .2s ease, background-color .2s ease;
}

.page-about .about-index__link:hover {
  color: var(--c-cobalt);
  border-color: var(--c-cobalt-soft);
}

.page-about .about-index__link:focus-visible {
  outline: 2px solid var(--c-turf);
  outline-offset: 2px;
}

.page-about .about-index__link.is-active,
.page-about .about-index__link[aria-current] {
  background: var(--c-cobalt);
  border-color: var(--c-cobalt);
  color: var(--c-paper);
}

/* ---------- 通用分栏 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(20px, 2.8vw, 36px);
}

.page-about .about-split__title {
  margin-top: 10px;
  font-size: clamp(26px, 3.4vw, 40px);
  line-height: 1.14;
  letter-spacing: -.02em;
}

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

@media (min-width: 880px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    column-gap: clamp(32px, 4.4vw, 76px);
    align-items: start;
  }

  .page-about .about-split--rev {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
  }

  .page-about .about-split__side {
    position: sticky;
    top: 108px;
  }
}

/* ---------- 事实清单 ---------- */
.page-about .about-factlist {
  list-style: none;
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: 0;
  border-top: 1px solid var(--about-line-ink);
}

.page-about .about-factlist li {
  display: grid;
  gap: 4px;
  padding: 13px 0;
  border-bottom: 1px solid var(--about-line-ink);
  font-size: 15px;
  line-height: 1.72;
  color: var(--ink-78);
}

.page-about .about-factlist a {
  color: var(--c-cobalt);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-factlist__k {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--cobalt, var(--c-cobalt));
  color: var(--c-cobalt);
}

@media (min-width: 620px) {
  .page-about .about-factlist li {
    grid-template-columns: 84px minmax(0, 1fr);
    gap: 18px;
    align-items: baseline;
  }
}

/* ---------- 时间轴 ---------- */
.page-about .about-head__title {
  margin-top: 10px;
  font-size: clamp(28px, 3.8vw, 46px);
  line-height: 1.12;
  letter-spacing: -.02em;
}

.page-about .about-head--ink .about-note-ink {
  color: var(--ink-62);
}

.page-about .about-rail {
  margin-top: clamp(26px, 3.6vw, 46px);
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  scroll-snap-type: x proximity;
  scrollbar-width: thin;
  padding-bottom: 16px;
}

.page-about .about-rail__track {
  position: relative;
  display: flex;
  gap: 0;
  min-width: max-content;
  margin: 0;
  padding: 30px 0 0;
  list-style: none;
}

.page-about .about-rail__track::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 7px;
  height: 1px;
  background: linear-gradient(90deg, rgba(57, 230, 122, .62) 0%, rgba(220, 233, 236, .2) 58%, rgba(220, 233, 236, .06) 100%);
}

.page-about .about-node {
  position: relative;
  flex: 0 0 clamp(224px, 24vw, 278px);
  padding: 0 26px 0 0;
  scroll-snap-align: start;
}

.page-about .about-node__dot {
  position: absolute;
  top: -23px;
  left: 0;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c-turf);
  box-shadow: 0 0 0 4px rgba(57, 230, 122, .16);
}

.page-about .about-node__season {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .07em;
  font-variant-numeric: tabular-nums;
  color: var(--c-amber);
}

.page-about .about-node__title {
  margin: 0 0 9px;
  font-size: 18px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--c-paper);
}

.page-about .about-node__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--fog-64);
}

.page-about .about-footnote {
  margin: clamp(26px, 3.4vw, 40px) 0 0;
  max-width: 44em;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--fog-64);
}

.page-about .about-footnote a {
  color: var(--c-turf);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-footnote--ink {
  color: var(--ink-62);
}

.page-about .about-footnote--ink a {
  color: var(--c-cobalt);
}

/* ---------- 六类判定树 ---------- */
.page-about .about-taxonomy {
  display: grid;
  gap: clamp(24px, 3.4vw, 42px);
  margin-top: clamp(24px, 3.4vw, 38px);
}

.page-about .about-taxonomy__tree {
  min-width: 0;
  padding: clamp(14px, 2vw, 22px);
  background: var(--c-paper);
  border: 1px solid var(--about-line-ink);
}

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

.page-about .about-tree__lines path {
  stroke: rgba(10, 20, 24, .22);
}

.page-about .about-tree__box {
  fill: var(--c-mist);
  stroke: rgba(10, 20, 24, .14);
  stroke-width: 1;
}

.page-about .about-tree__box--root {
  fill: var(--c-lake);
  stroke: var(--c-lake);
}

.page-about .about-tree__box--out {
  fill: rgba(57, 230, 122, .16);
  stroke: rgba(6, 42, 51, .28);
}

.page-about .about-tree__label {
  font-family: var(--font-sans);
  font-size: 15px;
  fill: var(--c-ink);
}

.page-about .about-tree__label--root {
  fill: var(--c-fog);
}

.page-about .about-cases {
  display: grid;
  gap: 10px;
  align-content: start;
  min-width: 0;
}

.page-about .about-case {
  background: var(--c-paper);
  border: 1px solid var(--about-line-ink);
}

.page-about .about-case > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 13px 15px;
  font-size: 15px;
  font-weight: 600;
  color: var(--c-ink);
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-case > summary::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--c-cobalt);
}

.page-about .about-case[open] > summary::after {
  content: "\2212";
}

.page-about .about-case > summary:focus-visible {
  outline: 2px solid var(--c-turf);
  outline-offset: -2px;
}

.page-about .about-case__body {
  padding: 12px 15px 15px;
  border-top: 1px solid var(--about-line-ink);
  background: var(--c-mist);
}

.page-about .about-case__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.76;
  color: var(--ink-62);
}

@media (min-width: 980px) {
  .page-about .about-taxonomy {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }
}

/* ---------- 编辑节奏 ---------- */
.page-about .about-cadence {
  list-style: none;
  margin: clamp(26px, 3.6vw, 44px) 0 0;
  padding: 0;
  border-top: 1px solid var(--about-line-ink);
}

.page-about .about-cadence__item {
  display: grid;
  gap: 10px;
  padding: clamp(20px, 2.6vw, 30px) 0;
  border-bottom: 1px solid var(--about-line-ink);
}

.page-about .about-cadence__time {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 700;
  letter-spacing: -.01em;
  font-variant-numeric: tabular-nums;
  color: var(--c-lake);
}

.page-about .about-cadence__time::after {
  content: "";
  display: block;
  width: 30px;
  height: 3px;
  margin-top: 9px;
  background: var(--c-amber);
}

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

.page-about .about-cadence__title {
  margin: 0 0 8px;
  font-size: 19px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--c-ink);
}

.page-about .about-cadence__body p {
  margin: 0;
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--ink-78);
}

@media (min-width: 720px) {
  .page-about .about-cadence__item {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: clamp(22px, 3.2vw, 44px);
    align-items: start;
  }
}

/* ---------- 更正说明卡 ---------- */
.page-about .about-note {
  margin-top: clamp(24px, 3.2vw, 36px);
  padding: 18px 18px 20px;
  background: var(--c-paper);
  border: 1px solid var(--about-line-ink);
  border-left: 4px solid var(--c-amber);
}

.page-about .about-note__k {
  margin: 0;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--ink-48);
}

.page-about .about-note__v {
  margin: 6px 0 10px;
  font-family: var(--font-mono);
  font-size: clamp(30px, 4.4vw, 44px);
  font-weight: 700;
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
  color: var(--c-lake);
}

.page-about .about-note__d {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--ink-62);
}

/* ---------- 协作网络图片 ---------- */
.page-about .about-figure--stack {
  margin-top: clamp(24px, 3.2vw, 36px);
}

/* ---------- 口径承诺 ---------- */
.page-about .about-pledge {
  list-style: none;
  margin: clamp(26px, 3.6vw, 46px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .about-pledge__item {
  background: rgba(11, 60, 73, .58);
  padding: clamp(20px, 2.6vw, 28px) clamp(18px, 2.4vw, 26px);
}

.page-about .about-pledge__no {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--c-turf);
}

.page-about .about-pledge__title {
  margin: 0 0 9px;
  font-size: 19px;
  line-height: 1.42;
  font-weight: 700;
  color: var(--c-paper);
}

.page-about .about-pledge__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--fog-64);
}

.page-about .about-closing {
  margin: clamp(28px, 3.6vw, 44px) 0 0;
  max-width: 46em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--fog-86);
}

.page-about .about-closing a {
  color: var(--c-turf);
  text-decoration: underline;
  text-underline-offset: 4px;
}

@media (min-width: 760px) {
  .page-about .about-pledge {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 动效退化 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link {
    transition: none;
  }

  .page-about [data-reveal] {
    opacity: 1;
    transform: none;
  }
}
<<<END>>>