.page-about {
  --about-rail: 190px;
  background: var(--base);
  color: var(--paper);
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
}

.page-about .about-hero__media {
  position: relative;
  overflow: hidden;
  border-bottom: 3px solid var(--ink);
}

.page-about .about-hero__media img {
  width: 100%;
  aspect-ratio: 2 / 1;
  object-fit: cover;
  filter: saturate(0.82) contrast(1.06);
}

.page-about .about-hero__media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(200, 255, 61, 0.16) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(200, 255, 61, 0.16) 1px, transparent 1px);
  background-size: 88px 88px;
  mix-blend-mode: screen;
}

.page-about .about-hero__stamp {
  position: absolute;
  left: 18px;
  bottom: 16px;
  z-index: 1;
  padding: 6px 10px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--lime);
  background: rgba(4, 21, 15, 0.74);
  border: 1px solid rgba(200, 255, 61, 0.42);
}

.page-about .about-hero__body {
  position: relative;
  z-index: 1;
  padding: 34px 0 56px;
}

.page-about .about-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 0 0 26px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--steel);
}

.page-about .about-crumb a {
  color: var(--steel);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding: 4px 0;
}

.page-about .about-crumb a:hover,
.page-about .about-crumb a:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

.page-about .about-hero__kicker {
  margin: 0 0 18px;
  color: var(--lime);
}

.page-about .about-hero__title {
  margin: 0 0 26px;
  word-break: break-word;
}

.page-about .about-hero__lede {
  max-width: 34em;
  margin: 0 0 36px;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(242, 246, 241, 0.84);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin: 0;
  padding: 24px 0 0;
  list-style: none;
  border-top: 2px solid rgba(140, 163, 180, 0.3);
}

.page-about .about-stats__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 6vw, 44px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--lime);
}

.page-about .about-stats__label {
  display: block;
  margin-top: 8px;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--steel);
}

/* ---------- 主体双栏 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  row-gap: 34px;
  padding-bottom: 88px;
}

.page-about .about-index__head {
  margin: 0 0 12px;
  color: var(--steel);
}

.page-about .about-index__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 4px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

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

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

.page-about .about-index__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 8px 12px;
  border: 2px solid rgba(140, 163, 180, 0.42);
  color: var(--paper);
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  border-color: var(--lime);
  color: var(--lime);
}

.page-about .about-index__num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--lime);
}

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

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding: 44px 0;
  border-top: 2px solid rgba(140, 163, 180, 0.24);
}

.page-about .about-chapter:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-chapter__label {
  margin: 0 0 14px;
  color: var(--orange);
}

.page-about .about-chapter .t-section {
  margin: 0 0 24px;
  color: var(--paper);
}

.page-about .about-chapter p {
  max-width: 36em;
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.78;
  color: rgba(242, 246, 241, 0.8);
}

/* ---------- 三类信息 ---------- */
.page-about .about-spec {
  margin-top: 30px;
}

.page-about .about-spec__row {
  padding: 26px 0 6px;
  border-top: 2px solid rgba(140, 163, 180, 0.24);
}

.page-about .about-spec__k {
  display: inline-block;
  margin-bottom: 12px;
  padding: 3px 9px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--base);
  background: var(--lime);
}

.page-about .about-spec__row .t-item {
  margin: 0 0 12px;
  color: var(--paper);
}

/* ---------- 大引用 ---------- */
.page-about .about-pull {
  margin: 40px 0 8px;
  padding: 30px 24px;
  background: var(--paper);
  color: var(--carbon);
  border-left: 8px solid var(--orange);
  box-shadow: var(--shadow-hard);
}

.page-about .about-pull blockquote {
  margin: 0;
  max-width: 22em;
  font-size: clamp(22px, 3.4vw, 40px);
  font-weight: 200;
  line-height: 1.22;
  letter-spacing: -0.01em;
}

.page-about .about-pull figcaption {
  margin-top: 16px;
  color: rgba(10, 26, 20, 0.65);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: 28px;
  margin-top: 26px;
}

.page-about .about-team__media {
  margin: 0;
}

.page-about .about-team__list {
  margin: 24px 0;
  padding: 0;
  list-style: none;
}

.page-about .about-team__list li {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 16px;
  align-items: baseline;
  padding: 16px 0;
  border-top: 1px solid rgba(140, 163, 180, 0.28);
}

.page-about .about-team__num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-team__list li > span:last-child {
  font-size: 15px;
  line-height: 1.7;
  color: rgba(242, 246, 241, 0.8);
}

/* ---------- 时间线 ---------- */
.page-about .about-tl-figure {
  margin: 0 0 40px;
}

.page-about .about-tl {
  position: relative;
  display: flex;
  flex-direction: column;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(to bottom, var(--steel), rgba(140, 163, 180, 0.14));
}

.page-about .about-tl__node {
  position: relative;
  padding: 0 0 30px 34px;
}

.page-about .about-tl__node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 2px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--lime);
  border: 3px solid var(--ink);
  box-shadow: 3px 3px 0 var(--ink);
}

.page-about .about-tl__detail summary {
  display: flex;
  flex-direction: column;
  gap: 6px;
  list-style: none;
  cursor: pointer;
  min-height: 44px;
  padding: 4px 0;
}

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

.page-about .about-tl__stage {
  color: var(--steel);
}

.page-about .about-tl__name {
  font-size: 17px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .about-tl__detail summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-tl__detail[open] summary::after {
  content: "−";
}

.page-about .about-tl__detail[open] .about-tl__name {
  color: var(--lime);
}

.page-about .about-tl__detail summary:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: 4px;
}

.page-about .about-tl .about-tl__detail p {
  max-width: 26em;
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(242, 246, 241, 0.75);
}

/* ---------- 判断清单 ---------- */
.page-about .about-tree {
  position: relative;
  margin: 28px 0 0;
  padding: 0 0 0 34px;
  list-style: none;
}

.page-about .about-tree::before {
  content: "";
  position: absolute;
  left: 10px;
  top: 8px;
  bottom: 20px;
  width: 2px;
  background: linear-gradient(to bottom, var(--steel), rgba(140, 163, 180, 0.12));
}

.page-about .about-tree__item {
  position: relative;
  padding: 0 0 24px;
}

.page-about .about-tree__item::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 18px;
  width: 24px;
  height: 2px;
  background: var(--steel);
  transition: background 0.2s var(--ease);
}

.page-about .about-tree__item:hover::before {
  background: var(--lime);
}

.page-about .about-tree__label {
  position: relative;
  display: grid;
  grid-template-columns: 24px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  cursor: pointer;
}

.page-about .about-tree__check {
  position: absolute;
  left: 0;
  top: 0;
  width: 24px;
  height: 24px;
  margin: 0;
  opacity: 0;
  cursor: pointer;
}

.page-about .about-tree__box {
  position: relative;
  width: 24px;
  height: 24px;
  border: 2px solid var(--steel);
  background: transparent;
  transition: background 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-tree__box::after {
  content: "";
  position: absolute;
  left: 6px;
  top: 1px;
  width: 7px;
  height: 13px;
  border-right: 3px solid var(--ink);
  border-bottom: 3px solid var(--ink);
  transform: rotate(42deg) scale(0);
  transform-origin: center;
  transition: transform 0.18s var(--ease);
}

.page-about .about-tree__check:checked + .about-tree__box {
  background: var(--lime);
  border-color: var(--lime);
}

.page-about .about-tree__check:checked + .about-tree__box::after {
  transform: rotate(42deg) scale(1);
}

.page-about .about-tree__check:focus-visible + .about-tree__box {
  outline: 2px solid var(--lime);
  outline-offset: 3px;
}

.page-about .about-tree__title {
  display: block;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.55;
  color: var(--paper);
}

.page-about .about-tree__num {
  margin-right: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .about-tree .about-tree__desc {
  max-width: 34em;
  margin: 8px 0 0 36px;
  font-size: 14.5px;
  line-height: 1.72;
  color: rgba(242, 246, 241, 0.72);
}

.page-about .about-tree .about-tree__tail {
  max-width: 34em;
  margin-top: 8px;
}

/* ---------- 合作 ---------- */
.page-about .about-partners {
  display: grid;
  margin: 26px 0 24px;
}

.page-about .about-partners__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  align-items: baseline;
  padding: 18px 0;
  border-top: 2px solid rgba(140, 163, 180, 0.26);
}

.page-about .about-partners__num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 5vw, 40px);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

.page-about .about-partners__item > span:last-child {
  font-size: 14px;
  line-height: 1.65;
  color: rgba(242, 246, 241, 0.8);
}

/* ---------- 收尾路径 ---------- */
.page-about .about-tail {
  padding: 60px 0 88px;
  border-top: 3px solid var(--ink);
  background: var(--base-2);
}

.page-about .about-tail__label {
  margin: 0 0 14px;
  color: var(--lime);
}

.page-about .about-tail .t-section {
  margin: 0 0 8px;
  color: var(--paper);
}

.page-about .about-tail__list {
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-tail__list li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 18px 0;
  border-top: 1px solid rgba(140, 163, 180, 0.28);
}

.page-about .about-tail__list a {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

.page-about .about-tail__list a:hover,
.page-about .about-tail__list a:focus-visible {
  color: var(--lime);
}

.page-about .about-tail__list li > span {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(242, 246, 241, 0.72);
}

/* ---------- 中等屏 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__body {
    padding: 44px 0 68px;
  }

  .page-about .about-hero__lede {
    font-size: 17px;
  }

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

  .page-about .about-partners {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 32px;
  }

  .page-about .about-tail__list li {
    grid-template-columns: 240px minmax(0, 1fr);
    gap: 24px;
    align-items: baseline;
  }
}

/* ---------- 团队局部两栏 ---------- */
@media (min-width: 900px) {
  .page-about .about-team {
    grid-template-columns: 5fr 7fr;
    gap: 44px;
    align-items: start;
  }

  .page-about .about-tl {
    flex-direction: row;
    align-items: flex-start;
  }

  .page-about .about-tl::before {
    left: 0;
    right: 0;
    top: 7px;
    bottom: auto;
    width: auto;
    height: 2px;
    background: linear-gradient(to right, var(--steel), rgba(140, 163, 180, 0.14));
  }

  .page-about .about-tl__node {
    padding: 34px 24px 0 0;
  }

  .page-about .about-tl__node::before {
    left: 0;
    top: 1px;
  }

  .page-about .about-tl__node:nth-child(1) {
    flex: 0 0 15%;
  }

  .page-about .about-tl__node:nth-child(2) {
    flex: 0 0 17%;
  }

  .page-about .about-tl__node:nth-child(3) {
    flex: 0 0 23%;
  }

  .page-about .about-tl__node:nth-child(4) {
    flex: 0 0 20%;
  }

  .page-about .about-tl__node:nth-child(5) {
    flex: 0 0 17%;
  }

  .page-about .about-tl__node:last-child {
    padding-right: 0;
  }
}

/* ---------- 桌面主栅格 ---------- */
@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: minmax(0, 1fr) var(--about-rail);
    column-gap: 56px;
    align-items: start;
    padding-bottom: 110px;
  }

  .page-about .about-main {
    grid-column: 1;
    grid-row: 1;
  }

  .page-about .about-index {
    grid-column: 2;
    grid-row: 1;
    position: sticky;
    top: calc(var(--header-h) + 32px);
    align-self: start;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
  }

  .page-about .about-index__list > li {
    flex: 1 1 auto;
  }

  .page-about .about-index__link {
    display: grid;
    grid-template-columns: 46px minmax(0, 1fr);
    gap: 10px;
    align-items: baseline;
    min-height: 0;
    padding: 12px 0;
    border: 0;
    border-top: 1px solid rgba(140, 163, 180, 0.28);
    white-space: normal;
    font-size: 13px;
    line-height: 1.5;
    color: rgba(242, 246, 241, 0.7);
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    color: var(--paper);
  }

  .page-about .about-index__num {
    font-size: 26px;
    font-weight: 200;
    line-height: 1;
    letter-spacing: -0.02em;
    color: var(--steel);
    transition: color 0.2s var(--ease);
  }

  .page-about .about-index__link:hover .about-index__num,
  .page-about .about-index__link:focus-visible .about-index__num {
    color: var(--lime);
  }

  .page-about .about-hero__lede {
    max-width: 38em;
  }

  .page-about .about-pull {
    padding: 40px 36px;
    margin: 48px 0 12px;
  }

  .page-about .about-chapter {
    padding: 64px 0;
  }
}

/* ---------- 窄屏兜底 ---------- */
@media (max-width: 420px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 10px;
  }

  .page-about .about-stats__label {
    font-size: 10px;
    letter-spacing: 0.06em;
  }

  .page-about .about-team__list li {
    grid-template-columns: 48px minmax(0, 1fr);
    gap: 12px;
  }

  .page-about .about-tree .about-tree__desc {
    margin-left: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .about-index__num,
  .page-about .about-tree__box,
  .page-about .about-tree__box::after,
  .page-about .about-tree__item::before,
  .page-about .about-tail__list a {
    transition: none;
  }
}
<<<END>>>