.page-about {
  --about-rail-item: clamp(216px, 68vw, 268px);
  --about-side-w: 152px;
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(26px, 5vw, 64px) 0 clamp(34px, 5.5vw, 76px);
  background:
    radial-gradient(120% 90% at 88% 4%, rgba(216, 231, 246, 0.95) 0%, rgba(216, 231, 246, 0) 58%),
    linear-gradient(180deg, #EAF2FB 0%, rgba(247, 245, 241, 0) 72%),
    var(--paper);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -6%;
  top: 12%;
  width: clamp(180px, 26vw, 340px);
  height: clamp(60px, 9vw, 110px);
  background: var(--orange);
  opacity: 0.1;
  transform: rotate(-9deg);
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4.5vw, 54px);
}

.page-about .about-hero__label {
  display: inline-block;
  margin-bottom: 16px;
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.15rem, 8.6vw, 5rem);
  line-height: 1.06;
  letter-spacing: -0.022em;
  color: var(--ink);
  max-width: 14em;
}

.page-about .about-hero__mark {
  position: relative;
  display: inline-block;
  padding: 0 0.06em;
}

.page-about .about-hero__mark::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0.08em;
  height: 0.14em;
  background: var(--orange);
  opacity: 0.32;
}

.page-about .about-hero__lead {
  margin: clamp(18px, 3vw, 28px) 0 0;
  max-width: 37em;
  font-size: clamp(15.5px, 1.6vw, 17.5px);
  line-height: 1.78;
  color: var(--gray);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-paper);
  align-self: end;
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px 18px;
  background: var(--paper);
}

.page-about .about-fact__value {
  font-size: clamp(1.5rem, 4.6vw, 2.15rem);
  line-height: 1;
  color: var(--blue-d);
  letter-spacing: -0.01em;
}

.page-about .about-fact__label {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gray);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-ch {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 42px);
}

.page-about .about-ch__side {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-ch__num {
  font-size: 1.55rem;
  color: var(--blue);
  letter-spacing: 0.02em;
  line-height: 1;
}

.page-about .about-ch__note {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--gray);
}

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

.page-about .about-ch__prose {
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .about-ch__prose p {
  color: var(--gray);
}

.page-about .about-ch__prose p + p {
  margin-top: 1em;
}

/* ---------- 01 起步 ---------- */
.page-about .about-origin__fig {
  margin-top: clamp(22px, 3.4vw, 36px);
}

.page-about .about-origin__fig img {
  border: 1px solid var(--line);
  box-shadow: var(--shadow-paper);
}

.page-about .about-pulse {
  list-style: none;
  margin: clamp(24px, 3.4vw, 36px) 0 0;
  padding: clamp(18px, 2.6vw, 24px) 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-pulse__item {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding-left: 14px;
  border-left: 2px solid var(--blue);
}

.page-about .about-pulse__k {
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--gray);
}

.page-about .about-pulse__v {
  font-size: 1.3rem;
  color: var(--ink);
  line-height: 1.1;
}

/* ---------- 02 团队 ---------- */
.page-about .about-team__split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 34px);
}

.page-about .about-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .about-role {
  position: relative;
  overflow: hidden;
  padding: 15px 16px 17px;
  background: var(--paper);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-paper);
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: baseline;
  gap: 6px 12px;
  transition: transform 0.24s var(--ease), border-color 0.24s var(--ease);
}

.page-about .about-role::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--orange);
  transform: scaleY(0);
  transform-origin: top center;
  transition: transform 0.26s var(--ease);
}

.page-about .about-role__t {
  font-size: 1rem;
  font-weight: 700;
  color: var(--blue-d);
  letter-spacing: 0.01em;
}

.page-about .about-role__n {
  font-size: 13px;
  color: var(--orange);
  letter-spacing: 0.08em;
}

.page-about .about-role p {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--gray);
}

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

.page-about .about-team__fig img {
  border: 1px solid var(--line);
  box-shadow: var(--shadow-paper);
}

@media (hover: hover) {
  .page-about .about-role:hover {
    transform: translate(2px, -2px);
    border-color: var(--orange-s);
  }
  .page-about .about-role:hover::before {
    transform: scaleY(1);
  }
}

/* ---------- 03 生产链路 ---------- */
.page-about .about-flow__list {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: about-flow;
}

.page-about .about-step {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 20px 0 22px;
  border-top: 1px solid var(--line);
}

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

.page-about .about-step__idx {
  font-size: 1.05rem;
  color: var(--orange);
  letter-spacing: 0.06em;
  line-height: 1;
}

.page-about .about-step__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.08rem, 2.4vw, 1.28rem);
  font-weight: 800;
  color: var(--ink);
  letter-spacing: -0.01em;
}

.page-about .about-step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--gray);
  max-width: 42em;
}

/* ---------- 04 版本时间轴 ---------- */
.page-about .about-rail-wrap {
  margin-top: clamp(24px, 3.6vw, 38px);
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x proximity;
  padding-bottom: 10px;
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail-wrap::-webkit-scrollbar {
  height: 6px;
}

.page-about .about-rail-wrap::-webkit-scrollbar-thumb {
  background: var(--line);
  border-radius: 3px;
}

.page-about .about-rail {
  list-style: none;
  margin: 0;
  padding: 2px 4px 6px 0;
  display: flex;
  align-items: flex-start;
  gap: 12px;
  min-width: max-content;
}

.page-about .about-rail__item {
  flex: 0 0 var(--about-rail-item);
  scroll-snap-align: start;
}

.page-about .about-rail__disc {
  border: 0;
}

.page-about .about-rail__node {
  width: 100%;
  display: grid;
  grid-template-columns: 11px auto minmax(0, 1fr) 14px;
  align-items: center;
  gap: 10px;
  padding: 14px 14px 14px 16px;
  background: var(--paper);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-paper);
  font: inherit;
  color: inherit;
  text-align: left;
  cursor: pointer;
  transition: transform 0.22s var(--ease), border-color 0.22s var(--ease);
}

.page-about .about-rail__dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--blue);
  box-shadow: 0 0 0 3px var(--blue-l);
}

.page-about .about-rail__num {
  font-size: 13px;
  color: var(--gray);
  letter-spacing: 0.06em;
}

.page-about .about-rail__name {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--ink);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.page-about .about-rail__mark {
  color: var(--gray);
}

.page-about .about-rail__disc .disclosure__inner {
  padding: 12px 4px 4px;
  font-size: 13.8px;
  line-height: 1.72;
  color: var(--gray);
}

.page-about .about-rail__disc .disclosure__inner p {
  margin: 0;
}

.page-about .about-rail__item--current .about-rail__node {
  border-color: var(--orange-s);
  background: #FFFBF7;
}

.page-about .about-rail__item--current .about-rail__dot {
  background: var(--orange);
  box-shadow: 0 0 0 3px var(--orange-s);
}

.page-about .about-rail__item--current .about-rail__num {
  color: var(--orange);
}

@media (hover: hover) {
  .page-about .about-rail__node:hover {
    transform: translateY(-2px);
    border-color: var(--blue-l);
  }
}

.page-about .about-versions__hint {
  margin: 10px 0 0;
  font-size: 12.5px;
  letter-spacing: 0.12em;
  color: var(--gray);
}

/* ---------- 05 合作 ---------- */
.page-about .about-partners__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-partner {
  padding: 18px 18px 20px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-top: 3px solid var(--blue);
  box-shadow: var(--shadow-paper);
  transition: transform 0.24s var(--ease), border-color 0.24s var(--ease);
}

.page-about .about-partner:nth-child(2) {
  border-top-color: var(--green);
}

.page-about .about-partner:nth-child(3) {
  border-top-color: var(--orange);
}

.page-about .about-partner__title {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--blue-d);
  letter-spacing: -0.01em;
}

.page-about .about-partner p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--gray);
}

.page-about .about-partners__fig {
  margin: clamp(22px, 3.2vw, 34px) 0 0;
}

.page-about .about-partners__fig img {
  border: 1px solid var(--line);
  box-shadow: var(--shadow-paper);
}

@media (hover: hover) {
  .page-about .about-partner:hover {
    transform: translateY(-3px);
  }
}

/* ---------- 06 会员与服务 ---------- */
.page-about .about-tiers {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-tier {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 18px 18px 20px;
  background: var(--paper);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-paper);
}

.page-about .about-tier--a {
  border-left: 4px solid var(--blue-l);
}

.page-about .about-tier--b {
  border-left: 4px solid var(--blue);
}

.page-about .about-tier--c {
  border-left: 4px solid var(--orange);
  background: linear-gradient(180deg, #FFFBF7 0%, var(--paper) 68%);
}

.page-about .about-tier__step {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--gray);
}

.page-about .about-tier__name {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.15rem, 2.6vw, 1.35rem);
  font-weight: 800;
  color: var(--blue-d);
  letter-spacing: -0.01em;
}

.page-about .about-tier p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--gray);
}

.page-about .about-promise {
  margin-top: clamp(26px, 4vw, 42px);
  padding: clamp(20px, 3vw, 28px);
  background: var(--blue-l);
  border-left: 4px solid var(--blue);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .about-promise__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.1rem, 2.6vw, 1.3rem);
  font-weight: 800;
  color: var(--blue-d);
}

.page-about .about-promise__text {
  margin: 0;
  max-width: 44em;
  font-size: 14.5px;
  line-height: 1.76;
  color: #2A3A48;
}

.page-about .about-promise__links {
  margin: 6px 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 结尾 ---------- */
.page-about .about-cta {
  margin-top: clamp(40px, 6.5vw, 84px);
  padding: clamp(30px, 4.6vw, 54px) 0;
  background:
    linear-gradient(115deg, var(--blue-d) 0%, #1B4E8A 62%, #1E5FA8 100%);
  color: var(--paper);
  position: relative;
  overflow: hidden;
}

.page-about .about-cta::after {
  content: "";
  position: absolute;
  right: -40px;
  bottom: -60px;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: var(--orange);
  opacity: 0.14;
  pointer-events: none;
}

.page-about .about-cta__inner {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.page-about .about-cta__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 4.4vw, 2.3rem);
  font-weight: 900;
  letter-spacing: -0.018em;
  color: #FFFFFF;
}

.page-about .about-cta__lead {
  margin: 10px 0 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.74;
  color: rgba(247, 245, 241, 0.82);
}

.page-about .about-cta__btns {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-cta .btn--ghost {
  border-color: rgba(247, 245, 241, 0.55);
  color: #FFFFFF;
}

@media (hover: hover) {
  .page-about .about-cta .btn--ghost:hover {
    border-color: #FFFFFF;
    background: rgba(247, 245, 241, 0.1);
  }
}

/* ---------- 响应式 ---------- */
@media (min-width: 600px) {
  .page-about .about-pulse {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-step {
    grid-template-columns: 56px minmax(0, 1fr);
    gap: 6px 20px;
    align-items: start;
  }

  .page-about .about-step__idx {
    grid-row: 1 / span 2;
    font-size: 1.15rem;
    padding-top: 2px;
  }

  .page-about .about-step p {
    grid-column: 2;
  }

  .page-about .about-partners__list {
    grid-template-columns: repeat(12, minmax(0, 1fr));
  }

  .page-about .about-partner:nth-child(1) {
    grid-column: span 5;
  }

  .page-about .about-partner:nth-child(2) {
    grid-column: span 7;
  }

  .page-about .about-partner:nth-child(3) {
    grid-column: span 12;
  }
}

@media (min-width: 720px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-ch {
    grid-template-columns: var(--about-side-w) minmax(0, 1fr);
    gap: clamp(26px, 3.4vw, 48px);
  }

  .page-about .about-ch__side {
    flex-direction: column;
    align-items: flex-start;
    gap: 18px;
    padding-bottom: 0;
    border-bottom: 0;
    position: sticky;
    top: calc(var(--topbar-h) + 24px);
    align-self: start;
  }

  .page-about .about-ch__note {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    max-height: 240px;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7.2fr) minmax(0, 4.8fr);
    align-items: end;
    gap: clamp(32px, 4vw, 68px);
  }

  .page-about .about-hero__lead {
    margin-top: 30px;
  }

  .page-about .about-team__split {
    grid-template-columns: minmax(0, 6.6fr) minmax(0, 5.4fr);
    align-items: start;
    gap: clamp(24px, 3vw, 40px);
  }

  .page-about .about-tiers {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .about-tier--a {
    grid-column: span 4;
  }

  .page-about .about-tier--b {
    grid-column: span 5;
  }

  .page-about .about-tier--c {
    grid-column: span 3;
  }

  .page-about .about-cta__inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 44px;
  }

  .page-about .about-cta__text {
    max-width: 46em;
  }

  .page-about .about-cta__btns {
    flex: 0 0 auto;
  }
}
<<<END>>>