.page-about {
  --about-rail: 216px;
  --about-gap: clamp(28px, 4vw, 76px);
  background: var(--c-white);
  color: var(--c-ink);
}

.page-about img {
  max-width: 100%;
  height: auto;
}

/* ---------- 面包屑 ---------- */
.page-about .about-top {
  padding-top: clamp(16px, 2.4vw, 28px);
}

.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-slate);
}

.page-about .breadcrumb a {
  color: var(--c-blue);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--step) var(--ease), color var(--step) var(--ease);
}

.page-about .breadcrumb a:hover {
  color: var(--c-red);
  border-bottom-color: var(--c-red);
}

.page-about .breadcrumb__sep {
  color: var(--c-grid);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(28px, 4.4vw, 60px) clamp(38px, 5.5vw, 82px);
  background:
    linear-gradient(158deg, rgba(63, 191, 168, 0.13), rgba(27, 58, 92, 0) 46%),
    linear-gradient(26deg, rgba(216, 6, 33, 0.09), rgba(255, 255, 255, 0) 54%),
    var(--c-white);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: min(40%, 440px);
  height: 3px;
  background: linear-gradient(90deg, var(--c-red), var(--c-orange));
}

.page-about .about-hero__inner {
  max-width: 66ch;
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  color: var(--c-navy);
}

.page-about .about-hero .lede {
  margin-top: clamp(18px, 2.2vw, 28px);
  max-width: 58ch;
  color: var(--c-ink);
}

.page-about .hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(28px, 4vw, 52px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--c-grid);
  border: var(--hair);
}

@media (min-width: 780px) {
  .page-about .hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .hero-stat {
  background: var(--c-white);
  padding: clamp(16px, 2vw, 26px) clamp(12px, 1.6vw, 22px);
}

.page-about .hero-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 34px);
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -0.01em;
  color: var(--c-red);
}

.page-about .hero-stat__label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--c-slate);
}

/* ---------- 叙事画布 ---------- */
.page-about .about-canvas {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-items: start;
  padding-block: clamp(38px, 5vw, 76px) clamp(52px, 7vw, 116px);
}

@media (min-width: 1000px) {
  .page-about .about-canvas {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    column-gap: var(--about-gap);
  }
}

/* ---------- 左侧刻度栏 ---------- */
.page-about .about-rail {
  margin-bottom: clamp(34px, 5vw, 0px);
  padding: 18px 20px;
  background: var(--c-mist);
  border-top: 3px solid var(--c-red);
}

.page-about .rail-title {
  margin: 0;
  color: var(--c-slate);
}

.page-about .rail-scale {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 26px;
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .rail-scale__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  text-decoration: none;
  color: inherit;
}

.page-about .rail-year {
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--c-blue);
  transition: color var(--step) var(--ease);
}

.page-about .rail-note {
  display: block;
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--c-slate);
}

.page-about .rail-aside {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: var(--hair);
  font-size: 13px;
  line-height: 1.72;
  color: var(--c-slate);
}

@media (hover: hover) {
  .page-about .rail-scale__link:hover .rail-year {
    color: var(--c-red);
  }
}

.page-about .rail-scale__link:focus-visible {
  outline: 2px solid var(--c-orange);
  outline-offset: 4px;
}

@media (min-width: 1000px) {
  .page-about .about-rail {
    position: sticky;
    top: 96px;
    margin-bottom: 0;
    padding: 4px 0 0;
    background: transparent;
    border-top: 0;
  }

  .page-about .rail-scale {
    position: relative;
    display: block;
    margin-top: 16px;
    padding-left: 18px;
  }

  .page-about .rail-scale::before {
    content: "";
    position: absolute;
    left: 3px;
    top: 10px;
    bottom: 10px;
    width: 1px;
    background: var(--c-grid);
  }

  .page-about .rail-scale__item {
    position: relative;
    padding-bottom: 28px;
  }

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

  .page-about .rail-scale__item::before {
    content: "";
    position: absolute;
    left: -19px;
    top: 8px;
    width: 7px;
    height: 7px;
    background: var(--c-grid);
    transition: background-color var(--step) var(--ease), transform var(--step) var(--ease);
  }

  .page-about .rail-scale__item:hover::before {
    background: var(--c-red);
    transform: scale(1.35);
  }

  .page-about .rail-scale__link {
    display: block;
  }

  .page-about .rail-year {
    display: block;
    font-size: 21px;
    line-height: 1.1;
  }

  .page-about .rail-note {
    margin-top: 5px;
  }
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  padding-block: clamp(34px, 4.6vw, 60px);
  border-top: var(--hair);
}

.page-about .about-body > .chapter:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .chapter--mist {
  background: linear-gradient(180deg, var(--c-mist), rgba(244, 245, 247, 0));
  padding-inline: clamp(16px, 2.6vw, 36px);
  margin-inline: calc(-1 * clamp(16px, 2.6vw, 36px));
}

.page-about .chapter__head .eyebrow {
  margin-bottom: 12px;
}

.page-about .chapter__head h2 {
  margin: 0;
  max-width: 20ch;
  color: var(--c-navy);
}

.page-about .chapter__body {
  margin-top: clamp(18px, 2.4vw, 30px);
  max-width: 68ch;
}

.page-about .chapter__body p {
  margin: 0 0 1.05em;
  line-height: 1.78;
}

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

.page-about .chapter__note {
  margin: clamp(20px, 2.6vw, 30px) 0 0;
  padding: 12px 0 12px 18px;
  border-left: 3px solid var(--c-red);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--c-blue);
}

.page-about .inline-link {
  color: var(--c-blue-mid);
  text-decoration: none;
  border-bottom: 1px solid var(--c-blue-mid);
  transition: color var(--step) var(--ease), border-color var(--step) var(--ease);
}

.page-about .inline-link:hover {
  color: var(--c-red);
  border-bottom-color: var(--c-red);
}

/* ---------- 图版 ---------- */
.page-about .figure {
  margin: clamp(26px, 3.6vw, 46px) 0 0;
}

.page-about .figure__frame {
  position: relative;
  overflow: hidden;
  background: var(--c-mist);
  border: var(--hair);
}

.page-about .figure__img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}

.page-about .figure__caption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-slate);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  margin: clamp(26px, 3.6vw, 42px) 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--hair);
}

.page-about .timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 22px 0 22px 24px;
  border-bottom: var(--hair);
  transition: background-color var(--step) var(--ease);
}

@media (min-width: 700px) {
  .page-about .timeline__item {
    grid-template-columns: 112px minmax(0, 1fr);
    gap: 26px;
    align-items: start;
  }
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 30px;
  width: 8px;
  height: 8px;
  background: var(--c-red);
  transition: transform var(--step) var(--ease);
}

@media (hover: hover) {
  .page-about .timeline__item:hover {
    background: var(--c-mist);
  }

  .page-about .timeline__item:hover::before {
    transform: scale(1.4);
  }
}

.page-about .timeline__item:target {
  background: var(--c-mist);
}

.page-about .timeline__year {
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.6vw, 28px);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--c-red);
}

.page-about .timeline__title {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--c-navy);
}

.page-about .timeline__body p {
  margin: 0;
  line-height: 1.72;
}

/* ---------- 折叠详情 ---------- */
.page-about .timeline-more {
  margin-top: clamp(22px, 3vw, 34px);
  border: var(--hair);
  background: var(--c-white);
}

.page-about .timeline-more summary {
  padding: 15px 18px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: var(--c-blue);
  transition: color var(--step) var(--ease);
}

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

.page-about .timeline-more summary::after {
  content: "+";
  float: right;
  font-size: 16px;
  line-height: 1;
  color: var(--c-red);
}

.page-about .timeline-more[open] summary::after {
  content: "—";
}

.page-about .timeline-more summary:hover {
  color: var(--c-red);
}

.page-about .timeline-more summary:focus-visible {
  outline: 2px solid var(--c-orange);
  outline-offset: -2px;
}

.page-about .timeline-more__body {
  padding: 4px 18px 20px;
  border-top: var(--hair);
}

.page-about .timeline-more__body p {
  margin: 14px 0 0;
  max-width: 70ch;
  line-height: 1.75;
  color: var(--c-ink);
}

/* ---------- 收尾行动区 ---------- */
.page-about .cta-strip {
  position: relative;
  overflow: hidden;
  margin-top: clamp(26px, 3.6vw, 46px);
  padding: clamp(24px, 3.4vw, 42px);
  display: grid;
  gap: 22px;
  background: linear-gradient(118deg, var(--c-navy), var(--c-blue) 56%, var(--c-red-deep));
  color: var(--c-white);
}

@media (min-width: 820px) {
  .page-about .cta-strip {
    grid-template-columns: minmax(0, 1.15fr) auto;
    align-items: center;
    gap: 36px;
  }
}

.page-about .cta-strip::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.06) 1px, transparent 1px);
  background-size: 52px 52px;
}

.page-about .cta-strip > * {
  position: relative;
  z-index: 1;
}

.page-about .cta-strip__text {
  margin: 0;
  font-size: clamp(15px, 1.5vw, 18px);
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.92);
}

.page-about .cta-strip__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .cta-strip .btn--ghost,
.page-about .cta-strip .btn--quiet {
  border-color: rgba(255, 255, 255, 0.44);
  color: var(--c-white);
}

.page-about .cta-strip .btn--ghost:hover,
.page-about .cta-strip .btn--quiet:hover {
  border-color: var(--c-orange);
  color: var(--c-orange);
}

/* ---------- 窄屏保护 ---------- */
@media (max-width: 520px) {
  .page-about .hero-stats {
    grid-template-columns: minmax(0, 1fr);
  }

  .page-about .chapter__head h2 {
    max-width: 100%;
  }

  .page-about .cta-strip__actions {
    flex-direction: column;
    align-items: stretch;
  }

  .page-about .cta-strip__actions .btn {
    text-align: center;
  }
}
<<<END>>>