.page-about {
  --rail-w: 0px;
  --about-line: var(--slate-line);
  background: var(--paper);
  color: var(--text);
  overflow-x: clip;
  padding-bottom: clamp(40px, 7vw, 88px);
}

@media (min-width: 900px) {
  .page-about {
    --rail-w: 72px;
  }
}

.page-about .breadcrumb {
  padding-top: 18px;
}

/* ---------- HERO ---------- */
.page-about .about-hero {
  padding-block: clamp(16px, 3vw, 30px) clamp(30px, 5vw, 56px);
  background:
    radial-gradient(circle at 92% 4%, rgba(61, 232, 200, .14), transparent 46%),
    linear-gradient(180deg, var(--paper) 0%, var(--paper) 62%, var(--slate) 100%);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 26px;
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.32fr) minmax(0, 1fr);
    gap: 44px;
    align-items: start;
  }
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.05rem, 5.4vw, 3.7rem);
  line-height: 1.05;
  letter-spacing: -0.01em;
  margin: 12px 0 0;
  max-width: 22ch;
}

.page-about .about-hero__intro {
  margin-top: 18px;
  font-size: clamp(1rem, 1.4vw, 1.075rem);
  line-height: 1.78;
  color: var(--text-sub);
  max-width: 36em;
}

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

.page-about .about-facts {
  position: relative;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px 14px;
  padding: 22px 22px 18px;
  background: var(--ink-deep);
  color: var(--paper);
  border-radius: var(--radius-l);
  overflow: hidden;
  box-shadow: var(--shadow-soft);
}

.page-about .about-facts::after {
  content: "";
  position: absolute;
  width: 180px;
  height: 180px;
  right: -70px;
  bottom: -90px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(61, 232, 200, .3), transparent 68%);
  pointer-events: none;
}

.page-about .about-facts__cell {
  padding: 14px 0 12px;
  border-top: 1px solid var(--mid);
  position: relative;
  z-index: 1;
}

.page-about .about-facts__cell:first-child,
.page-about .about-facts__cell:nth-child(2) {
  border-top-color: transparent;
}

.page-about .about-facts__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3.2vw, 1.9rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--cyan);
  line-height: 1.1;
}

.page-about .about-facts__key {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.5;
  color: rgba(244, 247, 245, .72);
}

.page-about .about-hero__band {
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .media-frame {
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius-l);
  background: var(--ink-deep);
}

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

/* ---------- CHAPTER SHELL ---------- */
.page-about .about-chapter {
  padding-block: clamp(34px, 5.5vw, 68px);
  border-top: 1px solid var(--about-line);
}

.page-about .about-chapter--versions {
  background: linear-gradient(180deg, var(--paper) 0%, var(--slate) 42%, var(--slate) 100%);
}

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

.page-about .about-chapter__inner {
  display: grid;
  gap: 18px;
}

@media (min-width: 900px) {
  .page-about .about-chapter__inner {
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: 32px;
  }
}

.page-about .about-rail {
  display: none;
}

@media (min-width: 900px) {
  .page-about .about-rail {
    display: block;
    position: relative;
    min-height: 42px;
    background-image: repeating-linear-gradient(
      180deg,
      var(--about-line) 0 1px,
      transparent 1px 26px
    );
    background-size: 22px 100%;
    background-position: right top;
    background-repeat: no-repeat;
  }
}

.page-about .about-rail__num {
  position: absolute;
  top: 0;
  right: 0;
  display: grid;
  place-items: center;
  width: 26px;
  height: 26px;
  border-radius: 4px;
  background: var(--cyan);
  color: var(--ink-deep);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0;
}

.page-about .about-chapter h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.45rem, 2.6vw, 2.15rem);
  line-height: 1.16;
  letter-spacing: -0.01em;
  margin: 10px 0 0;
  max-width: 26ch;
}

.page-about .prose {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text);
  max-width: 37em;
}

.page-about .prose + .prose {
  margin-top: 14px;
}

.page-about .prose p {
  margin: 0 0 12px;
}

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

/* ---------- 2:1 SPLIT ---------- */
.page-about .about-split {
  display: grid;
  gap: 20px;
  margin-top: 20px;
}

@media (min-width: 900px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
    gap: 36px;
    align-items: start;
  }
}

.page-about .about-aside {
  padding: 16px 18px;
  background: var(--slate);
  border-left: 3px solid var(--cyan);
  border-radius: var(--radius-s);
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-sub);
}

.page-about .about-aside p {
  margin: 0;
}

/* ---------- FLOW BAND ---------- */
.page-about .flow-band {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

@media (min-width: 720px) {
  .page-about .flow-band {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .flow-band {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .flow-step {
  position: relative;
  padding: 18px 16px 16px;
  background: #ffffff;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .flow-step::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: var(--cyan);
}

.page-about .flow-step--accent {
  background: var(--ink-deep);
  border-color: var(--panel);
  color: var(--paper);
}

.page-about .flow-step--accent::before {
  background: var(--orange);
}

.page-about .flow-step__n {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--text-sub);
}

.page-about .flow-step--accent .flow-step__n {
  color: var(--cyan-soft);
}

.page-about .flow-step h3 {
  margin: 8px 0 6px;
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0;
}

.page-about .flow-step p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text-sub);
}

.page-about .flow-step--accent p {
  color: rgba(244, 247, 245, .76);
}

.page-about .about-flow-figure {
  margin-top: 26px;
  background: var(--slate);
}

.page-about .about-flow-figure figcaption,
.page-about .about-team-figure figcaption {
  padding: 12px 16px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--text-sub);
  background: var(--slate);
}

/* ---------- TEAM ---------- */
.page-about .about-team-layout {
  display: grid;
  gap: 24px;
  margin-top: 20px;
}

@media (min-width: 1024px) {
  .page-about .about-team-layout {
    grid-template-columns: minmax(0, 1fr) minmax(0, 330px);
    gap: 34px;
    align-items: start;
  }
}

.page-about .team-grid {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

@media (min-width: 720px) {
  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
  }
  .page-about .team-card:nth-child(2) {
    margin-top: 26px;
  }
  .page-about .team-card:nth-child(3) {
    margin-top: 12px;
  }
}

.page-about .team-card {
  border-radius: var(--radius-m);
  border: 1px solid var(--about-line);
  padding: 18px 16px;
  background: #ffffff;
}

.page-about .team-card--dark {
  background: var(--ink-deep);
  border-color: var(--panel);
  color: var(--paper);
}

.page-about .team-card--slate {
  background: var(--slate);
  border-color: var(--slate-line);
}

.page-about .team-card__head {
  display: grid;
  gap: 4px;
  cursor: pointer;
  list-style: none;
}

.page-about .team-card__head::-webkit-details-marker {
  display: none;
}

.page-about .team-card__num {
  font-family: var(--font-mono);
  font-size: 40px;
  line-height: 1;
  font-weight: 600;
  letter-spacing: -0.03em;
  color: var(--ink-deep);
}

.page-about .team-card--dark .team-card__num {
  color: var(--cyan);
}

.page-about .team-card__name {
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 700;
  letter-spacing: 0;
}

.page-about .team-card__hint {
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--text-sub);
}

.page-about .team-card--dark .team-card__hint {
  color: rgba(244, 247, 245, .6);
}

.page-about .team-card__hint::after {
  content: "展开职责";
}

.page-about .team-card[open] .team-card__hint::after {
  content: "收起职责";
}

.page-about .team-card__body {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px dashed var(--about-line);
}

.page-about .team-card--dark .team-card__body {
  border-top-color: var(--mid);
}

.page-about .team-card__body p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--text-sub);
}

.page-about .team-card--dark .team-card__body p {
  color: rgba(244, 247, 245, .78);
}

.page-about .about-team-figure {
  margin: 0;
  border-radius: var(--radius-m);
  overflow: hidden;
  border: 1px solid var(--about-line);
}

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

/* ---------- COVERAGE ---------- */
.page-about .coverage-stats {
  list-style: none;
  margin: 22px 0 0;
  padding: 18px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  background: var(--slate);
  border-radius: var(--radius-l);
}

@media (min-width: 780px) {
  .page-about .coverage-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    padding: 22px;
    gap: 10px;
  }
}

.page-about .coverage-stats__item {
  padding: 14px 12px;
  background: rgba(244, 247, 245, .72);
  border-radius: var(--radius-s);
  border-left: 2px solid var(--cyan);
}

.page-about .coverage-stats__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.35rem, 2.6vw, 1.7rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--ink-deep);
  line-height: 1.15;
}

.page-about .coverage-stats__unit {
  display: block;
  margin-top: 5px;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--text-sub);
}

.page-about .about-subhead {
  margin: 32px 0 0;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0;
}

.page-about .audience-list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

@media (min-width: 780px) {
  .page-about .audience-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
  }
}

.page-about .audience-list li {
  padding: 14px 16px;
  background: #ffffff;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-s);
}

.page-about .audience-list strong {
  display: block;
  font-size: 14.5px;
  font-weight: 700;
  margin-bottom: 4px;
}

.page-about .audience-list span {
  display: block;
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-sub);
}

/* ---------- VERSIONS ---------- */
.page-about .version-band {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

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

@media (min-width: 1080px) {
  .page-about .version-band {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 8px;
  }
}

.page-about .version-node {
  padding: 18px 16px 16px;
  border-radius: var(--radius-m);
  border: 1px solid var(--about-line);
  outline-offset: 3px;
  transition: transform .2s var(--ease), box-shadow .2s var(--ease);
}

.page-about .version-node:hover,
.page-about .version-node:focus-visible {
  transform: translateY(-3px);
  box-shadow: var(--shadow-soft);
}

.page-about .version-node--v1 {
  background: var(--slate);
}

.page-about .version-node--v2 {
  background: #9FC3BA;
  border-color: #9FC3BA;
}

.page-about .version-node--v3 {
  background: var(--mid);
  border-color: var(--mid);
  color: var(--paper);
}

.page-about .version-node--v4 {
  background: var(--ink-deep);
  border-color: var(--panel);
  color: var(--paper);
}

.page-about .version-node__tag {
  display: block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--text-sub);
}

.page-about .version-node--v3 .version-node__tag,
.page-about .version-node--v4 .version-node__tag {
  color: var(--cyan-soft);
}

.page-about .version-node h3 {
  margin: 8px 0 6px;
  font-family: var(--font-display);
  font-size: 1.08rem;
  font-weight: 700;
  letter-spacing: 0;
}

.page-about .version-node p {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
}

.page-about .version-node--v1 p,
.page-about .version-node--v2 p {
  color: #1D3A33;
}

.page-about .version-node--v3 p,
.page-about .version-node--v4 p {
  color: rgba(244, 247, 245, .78);
}

.page-about .version-node__tags {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  transition: max-height .24s var(--ease), opacity .24s var(--ease), margin-top .24s var(--ease);
}

.page-about .version-node:hover .version-node__tags,
.page-about .version-node:focus-visible .version-node__tags,
.page-about .version-node:focus-within .version-node__tags {
  max-height: 8rem;
  opacity: 1;
  margin-top: 12px;
}

.page-about .version-node__tags li {
  padding: 4px 9px;
  border-radius: 999px;
  font-size: 11.5px;
  line-height: 1.5;
  border: 1px solid rgba(14, 22, 19, .18);
  color: #14312A;
}

.page-about .version-node--v3 .version-node__tags li,
.page-about .version-node--v4 .version-node__tags li {
  border-color: rgba(127, 240, 220, .4);
  color: var(--cyan-soft);
}

@media (hover: none) {
  .page-about .version-node__tags {
    max-height: 8rem;
    opacity: 1;
    margin-top: 12px;
  }
}

.page-about .about-versions-note {
  margin: 22px 0 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--text-sub);
}

.page-about .about-inline-link {
  color: var(--mid);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.page-about .about-inline-link:hover {
  color: var(--ink-deep);
}

/* ---------- PARTNERS ---------- */
.page-about .partner-grid {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

@media (min-width: 820px) {
  .page-about .partner-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }
}

.page-about .partner-card {
  padding: 22px 20px;
  border-radius: var(--radius-m);
  background: #ffffff;
  border: 1px solid var(--about-line);
}

.page-about .partner-card--alt {
  background: var(--ink-deep);
  border-color: var(--panel);
  color: var(--paper);
}

.page-about .partner-card__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--mid);
}

.page-about .partner-card--alt .partner-card__num {
  color: var(--cyan);
}

.page-about .partner-card h3 {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 700;
  letter-spacing: 0;
}

.page-about .partner-card p {
  margin: 0;
  font-size: 13.8px;
  line-height: 1.8;
  color: var(--text-sub);
}

.page-about .partner-card--alt p {
  color: rgba(244, 247, 245, .78);
}

/* ---------- IDENTITY ---------- */
.page-about .about-legal {
  margin-top: 22px;
  padding: 22px 20px;
  border-radius: var(--radius-l);
  background: var(--ink-deep);
  color: var(--paper);
}

.page-about .about-legal__list {
  margin: 0;
  display: grid;
  gap: 10px;
}

@media (min-width: 720px) {
  .page-about .about-legal__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }
}

.page-about .about-legal__item {
  padding: 12px 14px;
  border-radius: var(--radius-s);
  background: var(--panel);
}

.page-about .about-legal__item dt {
  font-size: 11.5px;
  letter-spacing: .08em;
  color: rgba(244, 247, 245, .62);
}

.page-about .about-legal__item dd {
  margin: 6px 0 0;
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.6;
  color: var(--cyan-soft);
  word-break: break-all;
}

.page-about .about-contact {
  margin-top: 16px;
  display: grid;
  gap: 8px;
}

.page-about .about-contact__row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 12px;
  padding: 11px 14px;
  border-radius: var(--radius-s);
  border: 1px solid var(--mid);
}

.page-about .about-contact__key {
  font-size: 12px;
  letter-spacing: .06em;
  color: rgba(244, 247, 245, .62);
  min-width: 56px;
}

.page-about .about-contact__val {
  font-size: 14px;
  line-height: 1.6;
  color: var(--paper);
  word-break: break-all;
}

.page-about .about-contact__val.num {
  font-family: var(--font-mono);
  letter-spacing: -0.01em;
}

.page-about .about-contact__btn {
  margin-left: auto;
  flex-shrink: 0;
}

.page-about .about-contact__row--wide .about-contact__val {
  flex: 1 1 220px;
}

.page-about .about-legal__note {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--mid);
  font-size: 12.5px;
  line-height: 1.75;
  color: rgba(244, 247, 245, .66);
}

.page-about .about-reach-link {
  margin: 18px 0 0;
  font-size: 13.8px;
  line-height: 1.8;
  color: var(--text-sub);
}

/* ---------- MOTION ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .version-node,
  .page-about .version-node__tags {
    transition: none;
  }
  .page-about .version-node:hover,
  .page-about .version-node:focus-visible {
    transform: none;
  }
}
<<<END>>>