.page-about {
  --about-axis: 96px;
  --about-pad: clamp(44px, 7vw, 96px);
  --about-soft: #4a4038;
  background: var(--sand);
  color: var(--ink);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about * {
  box-sizing: border-box;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-display);
  margin: 0;
}

.page-about .container {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

.page-about .prose {
  max-width: 36em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--about-soft);
}

.page-about .section-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--dansha);
  margin: 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(24px, 4vw, 48px) 0 clamp(38px, 6vw, 76px);
  background:
    radial-gradient(120% 90% at 92% 4%, rgba(178, 58, 34, 0.16), transparent 62%),
    radial-gradient(95% 80% at 4% 100%, rgba(28, 110, 106, 0.16), transparent 64%),
    linear-gradient(168deg, var(--sand) 0%, var(--gobi) 100%);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(to right, rgba(201, 169, 138, 0.28) 1px, transparent 1px);
  background-size: 96px 100%;
  pointer-events: none;
}

.page-about .about-hero .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  list-style: none;
  margin: 0 0 clamp(22px, 4vw, 44px);
  padding: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--about-soft);
}

.page-about .about-hero .breadcrumb li + li::before {
  content: "/";
  margin-right: 6px;
  color: var(--line);
}

.page-about .about-hero .breadcrumb a {
  color: var(--huanghe-mid);
  text-decoration: none;
}

.page-about .about-hero .breadcrumb a:hover,
.page-about .about-hero .breadcrumb a:focus-visible {
  text-decoration: underline;
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 40px);
}

.page-about .about-hero__title {
  font-size: clamp(40px, 9vw, 100px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  font-weight: 900;
  margin: 16px 0 0;
  color: var(--huanghe);
}

.page-about .about-hero__title em {
  font-style: normal;
  color: var(--dansha);
}

.page-about .about-hero__lead {
  margin: clamp(20px, 3vw, 30px) 0 0;
  max-width: 32em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-soft);
}

.page-about .about-hero__aside {
  position: relative;
  align-self: end;
  padding: 20px 18px;
  border: 1px solid var(--line);
  background: var(--glass);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.page-about .about-hero__aside::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(to bottom, var(--dansha), var(--huanghe-mid));
}

.page-about .about-hero__coords {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(24px, 4.4vw, 38px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--huanghe);
}

.page-about .about-hero__coords span:last-child {
  color: var(--dansha);
}

.page-about .about-hero__capt {
  margin: 14px 0 0;
  font-size: 12px;
  line-height: 1.7;
  color: var(--about-soft);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(32px, 5vw, 60px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-stats > li {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 16px 14px;
  background: var(--sand);
}

.page-about .about-stats__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.4vw, 34px);
  line-height: 1;
  color: var(--dansha);
}

.page-about .about-stats__txt {
  font-size: 12px;
  color: var(--about-soft);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  padding: var(--about-pad) 0;
}

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

.page-about .about-chapter__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 28px);
}

.page-about .about-chapter__note {
  display: flex;
  align-items: center;
  gap: 10px;
  border-left: 2px solid var(--dansha);
  padding-left: 12px;
  min-height: 24px;
}

.page-about .about-chapter__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--dansha);
}

.page-about .about-chapter__deg {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--huanghe-mid);
}

.page-about .about-chapter__title {
  font-size: clamp(26px, 4.4vw, 48px);
  line-height: 1.14;
  font-weight: 900;
  letter-spacing: -0.01em;
  margin: 0 0 clamp(16px, 2.4vw, 24px);
  color: var(--huanghe);
}

.page-about .about-chapter__body > p + p {
  margin-top: 14px;
}

.page-about .about-figure {
  margin: clamp(26px, 4vw, 40px) 0 0;
}

/* ---------- 方法论分段 ---------- */
.page-about .about-tabs {
  margin-top: clamp(22px, 3vw, 30px);
}

.page-about .about-tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
  margin-bottom: clamp(18px, 3vw, 26px);
}

.page-about .about-tabs__tab {
  font-family: var(--font-display);
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 10px 16px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--ink);
  font-size: 15px;
  cursor: pointer;
  transition: background 220ms ease, color 220ms ease, border-color 220ms ease;
}

.page-about .about-tabs__tab:hover {
  border-color: var(--dansha);
}

.page-about .about-tabs__tab:focus-visible {
  outline: 2px solid var(--huanghe);
  outline-offset: 2px;
}

.page-about .about-tabs__tab[aria-selected="true"] {
  background: var(--huanghe);
  border-color: var(--huanghe);
  color: var(--sand);
}

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

.page-about .about-tabs__tab[aria-selected="true"] .about-tabs__idx {
  color: var(--night);
}

.page-about .about-tabs__panel h3 {
  font-size: clamp(19px, 2.4vw, 24px);
  line-height: 1.35;
  color: var(--huanghe);
  margin: 0 0 10px;
}

.page-about .about-tabs__panel:focus-visible {
  outline: 2px solid var(--huanghe-mid);
  outline-offset: 4px;
}

.page-about .about-defs {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: clamp(16px, 2.6vw, 24px) 0 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-defs > div {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 12px 14px;
  background: var(--gobi);
}

.page-about .about-defs dt {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--huanghe);
}

.page-about .about-defs dd {
  margin: 0;
  font-size: 14px;
  color: var(--ink);
}

/* ---------- 团队分工 ---------- */
.page-about .about-roster {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(22px, 3vw, 32px);
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-roster__cell {
  padding: 20px 18px 22px;
  background: var(--sand);
}

.page-about .about-roster__tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--dansha);
  margin: 0 0 10px;
}

.page-about .about-roster__cell h3 {
  font-size: 18px;
  line-height: 1.4;
  color: var(--huanghe);
  margin: 0 0 8px;
}

.page-about .about-roster__cell p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--about-soft);
}

.page-about .about-roster + .prose {
  margin-top: clamp(18px, 3vw, 26px);
}

/* ---------- 时间轴（深色区） ---------- */
.page-about .about-chapter--dark {
  background: var(--huanghe);
  color: var(--sand);
  border-top: 1px solid var(--huanghe);
  background-image: radial-gradient(90% 70% at 88% 0%, rgba(198, 242, 78, 0.1), transparent 62%);
}

.page-about .about-chapter--dark .about-chapter__note {
  border-left-color: var(--night);
}

.page-about .about-chapter--dark .about-chapter__num,
.page-about .about-chapter--dark .about-chapter__deg {
  color: var(--night);
}

.page-about .about-chapter--dark .about-chapter__title {
  color: var(--sand);
}

.page-about .about-chapter--dark .prose {
  color: rgba(247, 242, 233, 0.78);
}

.page-about .about-timeline {
  list-style: none;
  margin: clamp(24px, 4vw, 38px) 0 0;
  padding: 0;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: rgba(231, 211, 179, 0.3);
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 clamp(26px, 3.6vw, 38px) 34px;
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline__dot {
  position: absolute;
  left: 0;
  top: 6px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  border: 1px solid var(--gobi);
  background: var(--huanghe);
}

.page-about .about-timeline__item--current .about-timeline__dot {
  background: var(--night);
  border-color: var(--night);
  box-shadow: 0 0 0 5px rgba(198, 242, 78, 0.16);
}

.page-about .about-timeline__phase {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--night);
  margin: 0 0 6px;
}

.page-about .about-timeline__item h3 {
  font-size: clamp(17px, 2.2vw, 21px);
  line-height: 1.4;
  color: var(--sand);
  margin: 0 0 8px;
}

.page-about .about-timeline__item p:not(.about-timeline__phase) {
  margin: 0;
  max-width: 34em;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(247, 242, 233, 0.76);
}

/* ---------- 地域与生态 ---------- */
.page-about .about-dots {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
}

.page-about .about-dots li {
  position: relative;
  padding-left: 18px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--huanghe);
}

.page-about .about-dots li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  transform: translateY(-50%);
  background: var(--dansha);
}

.page-about .about-dots li:nth-child(even)::before {
  background: var(--huanghe-mid);
}

/* ---------- 勘误复核 ---------- */
.page-about .about-fix {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(22px, 3vw, 32px);
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-fix__step {
  padding: 20px 18px 22px;
  background: var(--gobi);
}

.page-about .about-fix__tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--dansha);
  margin: 0 0 10px;
}

.page-about .about-fix__step h3 {
  font-size: 17px;
  line-height: 1.4;
  color: var(--huanghe);
  margin: 0 0 8px;
}

.page-about .about-fix__step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--about-soft);
}

.page-about .about-fix__addr {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  align-items: baseline;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding: 14px 16px;
  border-left: 3px solid var(--dansha);
  background: var(--sand);
  font-size: 13px;
  color: var(--about-soft);
}

.page-about .about-fix__addr span {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--huanghe);
  word-break: break-all;
}

/* ---------- 收尾入口 ---------- */
.page-about .about-outro {
  padding: clamp(40px, 6vw, 72px) 0 clamp(44px, 7vw, 80px);
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, var(--sand) 0%, var(--gobi) 100%);
}

.page-about .about-outro__title {
  font-size: clamp(24px, 3.6vw, 38px);
  line-height: 1.25;
  font-weight: 900;
  color: var(--huanghe);
  margin: 0 0 clamp(20px, 3vw, 30px);
  max-width: 20em;
}

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

.page-about .about-outro__link {
  display: inline-block;
  padding: 12px 20px;
  border: 1px solid var(--huanghe);
  color: var(--huanghe);
  font-size: 14px;
  text-decoration: none;
  transition: background 200ms ease, color 200ms ease;
}

.page-about .about-outro__link:hover,
.page-about .about-outro__link:focus-visible {
  background: var(--huanghe);
  color: var(--sand);
}

.page-about .about-outro__link--accent {
  background: var(--dansha);
  border-color: var(--dansha);
  color: var(--sand);
}

.page-about .about-outro__link--accent:hover,
.page-about .about-outro__link--accent:focus-visible {
  background: var(--huanghe);
  border-color: var(--huanghe);
  color: var(--sand);
}

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

  .page-about .about-stats > li {
    padding: 20px 18px;
  }

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

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

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

@media (min-width: 880px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.42fr) minmax(0, 0.58fr);
    align-items: end;
    column-gap: clamp(28px, 4vw, 64px);
  }

  .page-about .about-hero__lead {
    font-size: 18px;
  }

  .page-about .about-chapter__grid {
    grid-template-columns: var(--about-axis) minmax(0, 1fr);
    column-gap: clamp(24px, 4vw, 56px);
  }

  .page-about .about-chapter__note {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
    padding-top: 4px;
    align-self: start;
  }

  .page-about .about-chapter__deg {
    writing-mode: vertical-rl;
    letter-spacing: 0.22em;
    max-height: 220px;
  }

  .page-about .prose {
    font-size: 17px;
  }

  .page-about .about-figure {
    margin-left: calc(-1 * clamp(0px, 2vw, 0px));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tabs__tab,
  .page-about .about-outro__link {
    transition: none;
  }
}
<<<END>>>