.page-about {
  --about-slant: clamp(26px, 4vw, 48px);
  --about-pad: clamp(20px, 3vw, 36px);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about .about-crumb {
  padding-top: clamp(88px, 11vw, 124px);
}

.page-about .about-crumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--stone);
}

.page-about .about-crumb li {
  display: flex;
  align-items: center;
}

.page-about .about-crumb li + li::before {
  content: "/";
  margin-right: 10px;
  color: var(--sand);
}

.page-about .about-crumb a {
  color: var(--teal-600);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

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

.page-about .about-crumb [aria-current="page"] {
  color: var(--teal-800);
}

/* 首屏 */
.page-about .about-hero {
  padding: clamp(18px, 3vw, 32px) var(--gutter) clamp(26px, 4vw, 44px);
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(34px, 5.6vw, 66px);
  line-height: 1.02;
  letter-spacing: -.02em;
  color: var(--teal-800);
  margin: 14px 0 18px;
  max-width: 17ch;
}

.page-about .about-hero .lead {
  font-size: clamp(16px, 1.8vw, 18px);
  line-height: 1.78;
  letter-spacing: .01em;
  color: var(--ink);
  max-width: 62ch;
  margin: 0;
}

/* 通栏图 */
.page-about .about-banner {
  position: relative;
  margin: 0;
  overflow: hidden;
  background: var(--teal-900);
}

.page-about .about-banner img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: clamp(180px, 26vw, 320px);
  object-fit: cover;
}

.page-about .about-banner-cap {
  position: absolute;
  left: clamp(16px, 3vw, 40px);
  bottom: 0;
  padding: 9px 16px;
  background: rgba(7, 28, 26, .82);
  color: var(--sand-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
}

/* 斜切分隔 */
.page-about .about-slash {
  height: var(--about-slant);
  background: linear-gradient(90deg, var(--teal-800), var(--teal-600) 62%, var(--teal-500));
  clip-path: polygon(0 0, 100% 0, 100% 42%, 0 100%);
}

/* 双纵列 */
.page-about .about-body {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 44px);
  padding: clamp(34px, 5vw, 62px) var(--gutter) clamp(44px, 6vw, 84px);
}

/* 左侧时间轴 */
.page-about .about-rail-title {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--stone);
  margin: 0 0 12px;
  padding-left: 20px;
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 20px;
  position: relative;
  display: grid;
  gap: 2px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(to bottom, var(--sand), var(--sand-soft) 55%, var(--sand-wash));
}

.page-about .about-tl-link {
  position: relative;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 4px 10px;
  padding: 9px 10px 9px 8px;
  text-decoration: none;
  color: var(--teal-800);
  transition: background var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}

.page-about .about-tl-link:hover,
.page-about .about-tl-link:focus-visible {
  background: var(--sand-wash);
  padding-left: 12px;
}

.page-about .about-tl-link:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 2px;
}

.page-about .about-tl-mark {
  position: absolute;
  left: -20px;
  top: 14px;
  width: 12px;
  height: 12px;
  background: var(--teal-600);
  clip-path: polygon(0 0, 100% 0, 100% 58%, 58% 100%, 0 100%);
  transition: background var(--dur) var(--ease);
}

.page-about .about-tl-link:hover .about-tl-mark,
.page-about .about-tl-link:focus-visible .about-tl-mark {
  background: var(--cinnabar);
}

.page-about .about-tl-year {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--teal-600);
}

.page-about .about-tl-title {
  font-size: 14px;
  line-height: 1.4;
}

/* 右列正文 */
.page-about .about-sec {
  scroll-margin-top: 140px;
}

.page-about .about-sec + .about-sec {
  margin-top: clamp(34px, 5vw, 56px);
}

.page-about .about-sec + .about-sec::before {
  content: "";
  display: block;
  height: 2px;
  margin-bottom: clamp(22px, 3vw, 34px);
  background: linear-gradient(90deg, var(--sand), rgba(216, 162, 74, 0));
  transform: skewY(-1.4deg);
}

.page-about .about-sec:nth-of-type(odd) + .about-sec::before {
  transform: skewY(1.4deg);
}

.page-about .about-sec:target h2 {
  color: var(--cinnabar);
}

.page-about .about-sec h2 {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px 12px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(23px, 3vw, 34px);
  line-height: 1.22;
  letter-spacing: -.01em;
  color: var(--teal-800);
  margin: 0 0 18px;
  transition: color var(--dur) var(--ease);
}

.page-about .about-badge {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: .08em;
  color: var(--teal-800);
  border: 1px solid var(--sand);
  padding: 2px 7px;
  line-height: 1.4;
}

.page-about .about-sec p {
  font-size: 17px;
  line-height: 1.78;
  letter-spacing: .01em;
  max-width: 68ch;
  margin: 0 0 16px;
}

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

/* 三原则 */
.page-about .about-principles {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: clamp(20px, 3vw, 30px) 0 0;
}

.page-about .about-principle {
  position: relative;
  background: var(--sand-wash);
  padding: 44px 18px 22px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-principle:hover,
.page-about .about-principle:focus-visible {
  background: #EFDCBB;
  box-shadow: inset 0 0 0 2px var(--cinnabar);
  outline: none;
}

.page-about .about-principle-num {
  position: absolute;
  top: 12px;
  left: 14px;
  background: var(--cinnabar);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .06em;
  padding: 2px 7px;
}

.page-about .about-principle h3 {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 21px;
  line-height: 1.35;
  color: var(--teal-800);
  margin: 0 0 10px;
}

.page-about .about-principle p {
  font-size: 15.5px;
  line-height: 1.72;
  margin: 0;
  color: var(--teal-900);
}

/* 图片 */
.page-about .about-figure {
  margin: clamp(20px, 3vw, 30px) 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  background: var(--teal-800);
}

.page-about .about-figure figcaption {
  margin-top: 9px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .03em;
  color: var(--teal-600);
}

.page-about .about-figure--right {
  max-width: 520px;
  margin-left: auto;
}

.page-about .about-figure--wide {
  max-width: 660px;
}

/* 团队人数 */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 12px;
  margin: clamp(18px, 3vw, 26px) 0;
}

.page-about .about-stat {
  border-left: 2px solid var(--sand);
  padding-left: 12px;
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 4vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: var(--teal-800);
  letter-spacing: -.01em;
}

.page-about .about-stat-label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  letter-spacing: .02em;
  color: var(--teal-600);
}

/* 折叠补充 */
.page-about .about-details {
  margin: 18px 0 0;
  padding: 12px 16px;
  background: var(--sand-wash);
  border-left: 2px solid var(--sand);
}

.page-about .about-details summary {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 16px;
  color: var(--teal-800);
}

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

.page-about .about-details summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--cinnabar);
}

.page-about .about-details[open] summary::after {
  content: "–";
}

.page-about .about-details summary:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 3px;
}

.page-about .about-details p {
  margin: 10px 0 0;
  font-size: 15.5px;
  line-height: 1.75;
  max-width: 64ch;
}

/* 接下来 */
.page-about .about-next-list {
  list-style: none;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-next-list li {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 16px 0;
  border-bottom: 1px solid var(--hair);
}

.page-about .about-next-list li:first-child {
  border-top: 1px solid var(--hair);
}

.page-about .about-next-key {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--cinnabar);
}

.page-about .about-next-list li span:last-child {
  font-size: 16px;
  line-height: 1.72;
  max-width: 64ch;
}

/* 结尾入口 */
.page-about .about-cta {
  background: var(--sand-wash);
  padding: calc(var(--about-slant) + clamp(28px, 4vw, 48px)) 0 clamp(38px, 5vw, 62px);
  clip-path: polygon(0 var(--about-slant), 100% 0, 100% 100%, 0 100%);
}

.page-about .about-cta-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 34px);
}

.page-about .about-cta h2 {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(24px, 3.4vw, 38px);
  line-height: 1.2;
  letter-spacing: -.01em;
  color: var(--teal-800);
  margin: 12px 0 12px;
}

.page-about .about-cta-copy p:last-child {
  font-size: 16px;
  line-height: 1.75;
  color: var(--teal-900);
  max-width: 56ch;
  margin: 0;
}

.page-about .about-cta-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-content: start;
}

/* 中等屏幕 */
@media (min-width: 640px) {
  .page-about .about-principles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-next-list li {
    grid-template-columns: 92px minmax(0, 1fr);
    align-items: baseline;
    gap: 14px;
  }

  .page-about .about-details {
    padding: 14px 20px;
  }
}

/* 宽屏双纵列 */
@media (min-width: 900px) {
  .page-about .about-body {
    grid-template-columns: minmax(180px, 236px) minmax(0, 1fr);
    gap: clamp(32px, 4.5vw, 72px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 128px;
  }

  .page-about .about-hero {
    padding-top: clamp(24px, 3vw, 40px);
  }

  .page-about .about-cta-inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: end;
  }

  .page-about .about-cta-links {
    justify-content: flex-end;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl-link,
  .page-about .about-tl-mark,
  .page-about .about-principle,
  .page-about .about-sec h2 {
    transition: none;
  }
}
<<<END>>>