.page-about {
  --about-pad: clamp(20px, 4vw, 56px);
  --about-gap: clamp(18px, 2.6vw, 34px);
  background: linear-gradient(180deg, var(--deep) 0%, var(--ink) 32%, var(--ink) 100%);
  color: var(--bone);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about .about-shell {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 0 var(--gutter);
}

/* 面包屑 */
.page-about .about-crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  padding: 18px 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--steel);
}

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

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

/* 首屏 */
.page-about .about-hero {
  display: grid;
  gap: var(--about-gap);
  padding: 10px 0 var(--about-pad);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__text {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.page-about .about-hero h1 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(38px, 8.4vw, 82px);
  line-height: .98;
  letter-spacing: -.015em;
  color: var(--bone);
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 56ch;
  font-size: clamp(15px, 2.4vw, 18px);
  line-height: 1.8;
  color: rgba(243, 240, 228, .82);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 6px;
  background: var(--line-soft);
  border: 1px solid var(--line);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px;
  background: var(--moss);
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(26px, 5.4vw, 38px);
  line-height: 1;
  color: var(--lime);
}

.page-about .about-stat__num em {
  font-style: normal;
  font-size: .52em;
  margin-left: 3px;
  color: rgba(200, 255, 61, .8);
}

.page-about .about-stat__key {
  font-size: 12px;
  line-height: 1.5;
  color: var(--steel);
}

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

/* 图片容器 */
.page-about .figure {
  position: relative;
  margin: 0;
  border: 1px solid var(--line);
  background: var(--carbon);
  overflow: hidden;
}

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

.page-about .figure::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(157, 180, 196, .16) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(157, 180, 196, .16) 1px, transparent 1px);
  background-size: 46px 46px;
  opacity: .5;
}

.page-about .figure__caption {
  position: relative;
  z-index: 1;
  padding: 10px 14px 12px;
  font-family: var(--font-serif);
  font-size: 13px;
  line-height: 1.7;
  color: var(--steel);
  background: var(--carbon);
  border-top: 1px solid var(--line-soft);
}

/* 主栅格：索引 + 长文 */
.page-about .about-layout {
  display: grid;
  gap: var(--about-pad);
  padding: var(--about-pad) 0 0;
}

.page-about .about-index {
  border: 1px solid var(--line);
  background: rgba(17, 21, 20, .7);
  padding: 18px;
}

.page-about .about-index__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--clay);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
}

.page-about .about-index__list a {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 4px;
  font-size: 13px;
  color: var(--bone);
  text-decoration: none;
  border-bottom: 1px solid var(--line-soft);
}

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

.page-about .about-index__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--steel);
}

.page-about .about-index__note {
  margin: 16px 0;
  font-family: var(--font-serif);
  font-size: 13px;
  line-height: 1.8;
  color: var(--steel);
  border-left: 2px solid var(--slate);
  padding-left: 12px;
}

.page-about .about-index__cta {
  width: 100%;
  justify-content: center;
}

/* 章节通用 */
.page-about .about-section {
  padding: var(--about-pad) 0;
  border-top: 1px solid var(--line-soft);
}

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

.page-about .about-section__head {
  max-width: 68ch;
  margin-bottom: 26px;
}

.page-about .about-kicker {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--signal);
}

.page-about .about-section h2,
.page-about .about-cta h2 {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 5.2vw, 42px);
  line-height: 1.08;
  letter-spacing: -.01em;
  color: var(--bone);
}

.page-about .about-lede {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(243, 240, 228, .78);
}

.page-about .about-section h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 19px;
  line-height: 1.25;
  letter-spacing: .01em;
  color: var(--bone);
}

.page-about .about-section p {
  margin: 0 0 10px;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(243, 240, 228, .76);
}

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

/* 年份时间轴 */
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 14px;
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(236px, 1fr);
  gap: 16px;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-stop {
  position: relative;
  padding: 20px 16px 18px;
  border: 1px solid var(--line);
  border-top: 2px solid var(--slate);
  background: rgba(23, 53, 42, .55);
  scroll-snap-align: start;
}

.page-about .about-stop::before {
  content: "";
  position: absolute;
  top: -7px;
  left: 16px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--slate);
  border: 2px solid var(--ink);
}

.page-about .about-stop--now {
  border-top-color: var(--lime);
  background: rgba(23, 53, 42, .9);
}

.page-about .about-stop--now::before {
  background: var(--lime);
}

.page-about .about-stop__year {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 15px;
  letter-spacing: .04em;
  color: var(--steel);
}

.page-about .about-stop--now .about-stop__year {
  color: var(--lime);
}

/* 分栏（流程） */
.page-about .about-split {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-steps {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
}

.page-about .about-step {
  display: grid;
  grid-template-columns: 46px 1fr;
  gap: 4px 14px;
  padding: 16px;
  background: var(--carbon);
}

.page-about .about-step__num {
  grid-row: span 2;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 20px;
  line-height: 1.2;
  color: var(--lime);
}

.page-about .about-step h3 {
  margin: 0;
  font-size: 17px;
}

.page-about .about-step p {
  margin: 0;
  font-size: 13.5px;
}

.page-about .about-callout {
  margin-top: 20px;
  padding: 18px;
  border: 1px solid rgba(255, 107, 44, .45);
  background: linear-gradient(135deg, rgba(255, 107, 44, .13), rgba(255, 107, 44, .03));
}

.page-about .about-callout__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: .01em;
  color: var(--signal);
}

.page-about .about-split__figure {
  align-self: start;
}

/* 覆盖版图 / 标签 */
.page-about .about-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
}

.page-about .about-tabs .tab {
  padding: 9px 14px;
  font-family: var(--font-body);
  font-size: 13px;
  color: var(--steel);
  background: transparent;
  border: 1px solid var(--line);
  cursor: pointer;
  transition: color .18s ease, border-color .18s ease, background-color .18s ease;
}

.page-about .about-tabs .tab:hover,
.page-about .about-tabs .tab:focus-visible {
  color: var(--bone);
  border-color: var(--steel);
}

.page-about .about-tabs .tab[aria-selected="true"] {
  color: var(--ink);
  background: var(--lime);
  border-color: var(--lime);
}

.page-about .about-panel {
  padding: 18px;
  border: 1px solid var(--line);
  background: rgba(11, 31, 23, .6);
  margin-bottom: 12px;
}

.page-about .about-panel h3 {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 13px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--lime);
}

.page-about .about-tags {
  list-style: none;
  margin: 0 0 14px;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-tags li {
  padding: 7px 12px;
  font-size: 13px;
  color: var(--bone);
  border: 1px solid var(--line);
  background: rgba(60, 71, 66, .3);
}

.page-about .about-tags li:nth-child(4n+2) {
  border-color: rgba(157, 180, 196, .4);
  color: var(--steel);
}

.page-about .about-panel__note {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .about-coverage__figure {
  margin-top: 22px;
}

/* 团队与协作 */
.page-about .about-numbers {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-bottom: 22px;
}

.page-about .about-number {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: 16px;
  padding: 16px;
  background: var(--moss);
}

.page-about .about-number__num {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(30px, 7vw, 46px);
  line-height: 1;
  color: var(--lime);
}

.page-about .about-number__label {
  font-size: 13.5px;
  line-height: 1.7;
  color: rgba(243, 240, 228, .82);
}

.page-about .about-roles {
  display: grid;
  gap: 8px;
}

.page-about .about-role {
  border: 1px solid var(--line);
  background: var(--carbon);
}

.page-about .about-role summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 17px;
  color: var(--bone);
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-role summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--steel);
}

.page-about .about-role[open] summary::after {
  content: "−";
  color: var(--lime);
}

.page-about .about-role[open] summary {
  border-bottom: 1px solid var(--line-soft);
}

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

.page-about .about-role p {
  padding: 12px 16px 16px;
  font-size: 13.5px;
  color: rgba(243, 240, 228, .76);
}

/* 版本演进 */
.page-about .about-versions {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-versions__lead .btn {
  margin-top: 8px;
}

.page-about .about-version-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-version {
  padding: 18px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--slate);
  background: rgba(17, 21, 20, .82);
}

.page-about .about-version__tag {
  display: inline-block;
  margin: 0 0 10px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--lime);
  border: 1px solid rgba(200, 255, 61, .45);
}

.page-about .about-version__tag--signal {
  color: var(--signal);
  border-color: rgba(255, 107, 44, .5);
}

.page-about .about-version__tag--clay {
  color: var(--clay);
  border-color: rgba(185, 113, 82, .55);
}

/* 适用人群 */
.page-about .about-audience {
  margin: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
  counter-reset: aud;
}

.page-about .about-audience__item {
  padding: 18px;
  background: var(--carbon);
}

.page-about .about-audience dt {
  margin-bottom: 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: .01em;
  color: var(--bone);
}

.page-about .about-audience dt::before {
  counter-increment: aud;
  content: counter(aud, decimal-leading-zero);
  margin-right: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--signal);
}

.page-about .about-audience dd {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.85;
  color: rgba(243, 240, 228, .76);
}

.page-about .about-audience dd a {
  display: inline-block;
  margin-left: 4px;
  color: var(--lime);
  text-decoration: none;
  border-bottom: 1px solid rgba(200, 255, 61, .4);
}

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

/* 收尾 */
.page-about .about-cta {
  margin: var(--about-pad) 0 0;
  padding: clamp(22px, 4vw, 40px);
  border: 1px solid var(--line);
  background:
    radial-gradient(120% 140% at 100% 0%, rgba(200, 255, 61, .12), transparent 60%),
    var(--moss);
}

.page-about .about-cta__kicker {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--lime);
}

.page-about .about-cta p {
  max-width: 58ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(243, 240, 228, .82);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.page-about .about-cta__actions .btn {
  justify-content: center;
}

/* 平板及以上 */
@media (min-width: 720px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-index__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-numbers {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

/* 桌面：非对称双栏与横向时间轴 */
@media (min-width: 1000px) {
  .page-about .about-hero {
    grid-template-columns: 7fr 5fr;
    align-items: start;
    padding-top: 24px;
  }

  .page-about .about-hero__figure {
    margin-top: 8px;
  }

  .page-about .about-layout {
    grid-template-columns: 216px minmax(0, 1fr);
    align-items: start;
    gap: calc(var(--about-gap) * 1.6);
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--bar-h) + 22px);
  }

  .page-about .about-index__list {
    grid-template-columns: 1fr;
  }

  .page-about .about-timeline {
    grid-auto-flow: row;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    overflow: visible;
    padding-bottom: 0;
    gap: 0;
  }

  .page-about .about-stop {
    border: 0;
    border-top: 2px solid var(--slate);
    background: transparent;
    padding: 22px 16px 0 0;
  }

  .page-about .about-stop--now {
    border-top-color: var(--lime);
    background: linear-gradient(180deg, rgba(200, 255, 61, .08), transparent 70%);
  }

  .page-about .about-stop::before {
    left: 0;
  }

  .page-about .about-stop--now::before {
    left: 0;
  }

  .page-about .about-split {
    grid-template-columns: 8fr 4fr;
    align-items: start;
  }

  .page-about .about-split__figure {
    position: sticky;
    top: calc(var(--bar-h) + 22px);
  }

  .page-about .about-versions {
    grid-template-columns: 5fr 7fr;
    align-items: start;
  }

  .page-about .about-section__head {
    margin-bottom: 32px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tabs .tab {
    transition: none;
  }
}
<<<PAGE_CSS_END>>>