.page-about {
  --about-body: rgba(245, 243, 238, .80);
  --about-body-soft: rgba(245, 243, 238, .62);
  --about-teal-deep: #0E8F80;
  padding-bottom: clamp(48px, 8vw, 96px);
}

/* ============ 开场 ============ */
.page-about .about-open {
  padding: clamp(22px, 4vw, 48px) 0 clamp(8px, 2vw, 18px);
}

.page-about .about-open__grid {
  row-gap: clamp(24px, 4vw, 44px);
  align-items: start;
}

.page-about .about-open__lead {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.page-about .about-open__h1 {
  margin: 16px 0 0;
  font-size: clamp(30px, 5vw, 58px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  font-weight: 800;
}

.page-about .about-open__lede {
  margin-top: 20px;
  max-width: 48ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .about-open__media {
  margin-top: 4px;
}

.page-about .about-open__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: clamp(24px, 3.6vw, 36px);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.page-about .fact {
  padding: 14px 16px 16px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .fact__num {
  font-family: var(--font-sans);
  font-size: clamp(26px, 3.6vw, 38px);
  font-weight: 300;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .fact__unit {
  margin-left: 3px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--amber);
}

.page-about .fact__label {
  display: block;
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--slate);
}

/* ============ 历程 ============ */
.page-about .chronicle__title,
.page-about .pledge__title,
.page-about .team__title {
  margin: 10px 0 0;
  font-size: clamp(22px, 2.8vw, 36px);
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .chronicle__intro,
.page-about .pledge__intro {
  margin-top: 14px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .chronicle__grid {
  margin-top: clamp(22px, 3.4vw, 36px);
  row-gap: 20px;
}

.page-about .year-block {
  padding: 22px 0 26px;
  border-top: 1px solid var(--line);
}

.page-about .year-block:first-child {
  border-top-color: var(--line-cyan);
}

.page-about .year-block__year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .2em;
  color: var(--cyan);
}

.page-about .year-block__title {
  margin: 10px 0 12px;
  font-size: clamp(18px, 2.1vw, 25px);
  line-height: 1.35;
  font-weight: 700;
  color: var(--paper);
}

.page-about .year-block__text {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--about-body);
}

.page-about .chronicle__aside {
  position: relative;
}

.page-about .chronicle__aside .rail {
  position: sticky;
  top: 104px;
  padding: 16px 0 0;
  border-top: 1px solid var(--line-amber);
}

.page-about .chronicle__aside .rail__label {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--amber);
}

.page-about .chronicle__aside .rail__list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .chronicle__aside .rail__item {
  margin: 0;
}

.page-about .chronicle__aside .rail__link {
  display: inline-block;
  padding: 4px 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .18em;
  color: var(--slate);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .chronicle__aside .rail__link:hover,
.page-about .chronicle__aside .rail__link:focus-visible,
.page-about .chronicle__aside .rail__link.is-active {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .about-figure {
  margin: clamp(26px, 4vw, 46px) 0 0;
}

.page-about .about-figure--flush {
  margin-top: 0;
}

.page-about .about-figure__cap {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  line-height: 1.7;
  color: var(--slate);
}

/* ============ 承诺 ============ */
.page-about .pledge__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: clamp(22px, 3.4vw, 34px);
}

.page-about .pledge {
  position: relative;
  padding: 24px 22px 28px;
  background: var(--ink-800);
  clip-path: var(--cut);
  transition: transform 240ms var(--ease), background-color 240ms var(--ease);
}

.page-about .pledge::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 52px;
  height: 3px;
  background: var(--cyan);
}

.page-about .pledge:nth-child(2)::before {
  background: var(--amber);
}

.page-about .pledge:nth-child(3)::before {
  background: var(--moss);
}

.page-about .pledge:hover {
  transform: translateY(-3px);
  background: #15304a;
}

.page-about .pledge__head {
  margin: 14px 0 10px;
  font-size: clamp(17px, 1.9vw, 21px);
  line-height: 1.45;
  font-weight: 700;
  color: var(--paper);
}

.page-about .pledge__body {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--about-body);
}

/* ============ 团队 ============ */
.page-about .team__figure {
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .team__copy {
  margin-top: clamp(20px, 3vw, 30px);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.page-about .team__lead {
  margin: 0;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.9;
  color: var(--paper);
}

.page-about .team__text {
  margin: 16px 0 0;
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--about-body-soft);
}

.page-about .flow {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .flow__item {
  position: relative;
  padding: 0 0 20px;
  border-bottom: 1px solid var(--line-soft);
  transition: border-color 220ms var(--ease);
}

.page-about .flow__item:hover,
.page-about .flow__item:focus-within {
  border-bottom-color: var(--line-cyan);
}

.page-about .flow__dot {
  display: block;
  width: 12px;
  height: 12px;
  margin-bottom: 14px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 2px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(53, 224, 208, .10);
  transition: box-shadow 240ms var(--ease);
}

.page-about .flow__item:hover .flow__dot {
  box-shadow: 0 0 0 8px rgba(53, 224, 208, .16);
}

.page-about .flow__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--amber);
}

.page-about .flow__title {
  margin: 8px 0 10px;
  font-size: clamp(17px, 1.9vw, 21px);
  line-height: 1.4;
  font-weight: 700;
  color: var(--paper);
}

.page-about .flow__text {
  margin: 0;
  max-width: 44ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--about-body);
}

/* ============ 标签重构 ============ */
.page-about .reframe__paper {
  padding: clamp(24px, 4vw, 48px);
  background: var(--paper);
  color: var(--ink-700);
  clip-path: var(--cut);
}

.page-about .reframe__eyebrow {
  color: var(--about-teal-deep);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
}

.page-about .reframe__title {
  margin: 12px 0 0;
  font-size: clamp(22px, 2.8vw, 34px);
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink-700);
}

.page-about .reframe__figures {
  display: flex;
  align-items: flex-end;
  flex-wrap: wrap;
  gap: 12px 20px;
  margin: clamp(20px, 3vw, 30px) 0 clamp(20px, 3vw, 28px);
  padding-bottom: clamp(18px, 2.6vw, 24px);
  border-bottom: 1px solid rgba(10, 22, 34, .14);
}

.page-about .reframe__figure {
  display: flex;
  flex-direction: column;
}

.page-about .reframe__num {
  font-family: var(--font-sans);
  font-size: clamp(46px, 9vw, 88px);
  font-weight: 300;
  line-height: .95;
  letter-spacing: -0.04em;
  color: rgba(10, 22, 34, .30);
}

.page-about .reframe__num--new {
  color: var(--about-teal-deep);
}

.page-about .reframe__label {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: rgba(10, 22, 34, .58);
}

.page-about .reframe__arrow {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--about-teal-deep);
  padding-bottom: 18px;
}

.page-about .reframe__body {
  row-gap: 18px;
}

.page-about .reframe__sub {
  margin: 0 0 10px;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink-700);
}

.page-about .reframe__body p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.9;
  color: rgba(10, 22, 34, .78);
}

/* ============ 引用合作 ============ */
.page-about .cite {
  padding: clamp(24px, 3.8vw, 44px);
  background:
    linear-gradient(180deg, rgba(201, 185, 163, .12), rgba(201, 185, 163, .03));
  border: 1px dashed rgba(201, 185, 163, .30);
}

.page-about .cite__eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--sand);
}

.page-about .cite__title {
  margin: 12px 0 0;
  font-size: clamp(21px, 2.6vw, 32px);
  line-height: 1.3;
  font-weight: 700;
  color: var(--paper);
}

.page-about .cite__text {
  margin: 16px 0 0;
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--about-body);
}

.page-about .cite__list {
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .cite__item {
  padding-top: 12px;
  border-top: 1px dashed rgba(201, 185, 163, .24);
  font-size: 14px;
  line-height: 1.8;
  color: var(--about-body);
}

.page-about .cite__key {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--amber);
}

/* ============ 收束 ============ */
.page-about .close__panel {
  padding: clamp(24px, 4vw, 46px);
  background: var(--ink-800);
  clip-path: var(--cut);
}

.page-about .close__grid {
  row-gap: 24px;
}

.page-about .close__title {
  margin: 12px 0 0;
  font-size: clamp(22px, 2.8vw, 34px);
  line-height: 1.25;
  font-weight: 700;
  color: var(--paper);
}

.page-about .close__text {
  margin: 16px 0 0;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--about-body);
}

.page-about .close__actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
  justify-content: center;
}

.page-about .close__actions .btn {
  width: 100%;
  text-align: center;
}

/* ============ 断点 ============ */
@media (min-width: 700px) {
  .page-about .about-open__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .pledge__grid {
    gap: 16px;
  }

  .page-about .cite__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .cite__item {
    padding-top: 14px;
  }
}

@media (min-width: 860px) {
  .page-about .pledge__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 28px;
  }

  .page-about .flow::before {
    content: "";
    position: absolute;
    left: 6%;
    right: 6%;
    top: 6px;
    height: 1px;
    background: linear-gradient(90deg, var(--line-cyan), rgba(53, 224, 208, .12));
    pointer-events: none;
  }

  .page-about .flow__dot {
    position: relative;
    z-index: 1;
    margin-top: -6px;
  }

  .page-about .flow__item {
    padding-bottom: 0;
    border-bottom: 0;
    border-top: 1px solid transparent;
  }

  .page-about .flow__text {
    max-width: 34ch;
  }

  .page-about .chronicle__grid {
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .page-about .about-open {
    padding-top: clamp(30px, 3.4vw, 56px);
  }

  .page-about .chronicle__aside .rail__list {
    flex-direction: column;
    gap: 0;
  }

  .page-about .chronicle__aside .rail__link {
    padding: 7px 0;
    font-size: 14px;
  }

  .page-about .close__actions {
    align-items: stretch;
  }
}

@media (max-width: 899px) {
  .page-about .chronicle__aside {
    order: -1;
  }

  .page-about .chronicle__aside .rail {
    position: static;
    top: auto;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .pledge,
  .page-about .flow__dot,
  .page-about .chronicle__aside .rail__link {
    transition: none;
  }

  .page-about .pledge:hover {
    transform: none;
  }
}
<<<END>>>