.page-about {
  --about-rail: 44px;
  padding-bottom: 88px;
}

.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  letter-spacing: .02em;
  color: var(--muted);
  margin-bottom: 30px;
}

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

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  border-bottom-color: currentColor;
}

.page-about .breadcrumb [aria-current="page"] {
  color: var(--gold-sand);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: 30px;
  margin-bottom: clamp(52px, 8vw, 104px);
}

.page-about .about-hero__text h1 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.01em;
  font-size: clamp(30px, 5.2vw, 50px);
  line-height: 1.2;
  color: var(--paper);
  margin: 12px 0 18px;
  max-width: 15em;
}

.page-about .about-hero__text .lede {
  color: rgba(244, 238, 227, .78);
  font-size: clamp(16px, 1.6vw, 18px);
  line-height: 1.8;
  max-width: 34em;
}

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

.page-about .about-hero__media::after {
  content: "";
  position: absolute;
  inset: auto -8px -8px auto;
  width: 42%;
  height: 42%;
  border-right: 1px solid rgba(201, 162, 39, .5);
  border-bottom: 1px solid rgba(201, 162, 39, .5);
  border-radius: 0 0 18px 0;
  pointer-events: none;
}

/* ---------- 通用排版 ---------- */
.page-about .section-head {
  max-width: 46em;
  margin-bottom: 30px;
}

.page-about .section-title {
  font-family: var(--font-display);
  font-size: clamp(23px, 3.2vw, 34px);
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--paper);
  margin: 10px 0 14px;
}

.page-about .prose {
  color: rgba(244, 238, 227, .76);
  font-size: 16px;
  line-height: 1.78;
  max-width: 36em;
  margin: 0 0 14px;
}

.page-about .meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
  margin: 0 0 6px;
}

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

/* ---------- 版本沿革 ---------- */
.page-about .versions {
  margin-bottom: clamp(56px, 9vw, 112px);
}

.page-about .versions__jump {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 10px;
  padding: 14px 0;
  border-top: var(--rule);
  border-bottom: var(--rule);
  margin-bottom: 42px;
}

.page-about .versions__jump-label {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--muted);
  margin-right: 6px;
}

.page-about .versions__jump a {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--gold-sand);
  text-decoration: none;
  padding: 5px 13px;
  border: 1px solid rgba(231, 214, 164, .3);
  border-radius: 999px;
  transition: color var(--ease), background-color var(--ease), border-color var(--ease);
}

.page-about .versions__jump a:hover,
.page-about .versions__jump a:focus-visible {
  color: var(--ink-deep);
  background: var(--gold);
  border-color: var(--gold);
}

.page-about .versions__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .version {
  position: relative;
  display: grid;
  grid-template-columns: var(--about-rail) minmax(0, 1fr);
  column-gap: 16px;
  padding-bottom: 62px;
  scroll-margin-top: 96px;
}

.page-about .version::before {
  content: "";
  position: absolute;
  left: 21px;
  top: 10px;
  bottom: 0;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, rgba(201, 162, 39, .8), rgba(201, 162, 39, .16));
}

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

.page-about .version:last-child::before {
  background: linear-gradient(180deg, rgba(201, 162, 39, .8), rgba(201, 162, 39, 0));
}

.page-about .version__dot {
  position: relative;
  z-index: 1;
  grid-column: 1;
  justify-self: center;
  align-self: start;
  margin-top: 8px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 6px var(--ink-deep);
}

.page-about .version--v1 .version__dot {
  width: 10px;
  height: 10px;
  margin-top: 11px;
  background: rgba(201, 162, 39, .55);
}

.page-about .version--v2 .version__dot {
  width: 13px;
  height: 13px;
  background: rgba(201, 162, 39, .78);
}

.page-about .version--v3 .version__dot {
  width: 16px;
  height: 16px;
  margin-top: 7px;
}

.page-about .version--v4 .version__dot {
  width: 22px;
  height: 22px;
  margin-top: 4px;
  animation: aboutPulse 3s ease-in-out infinite;
}

@keyframes aboutPulse {
  0%, 100% {
    box-shadow: 0 0 0 6px var(--ink-deep), 0 0 0 12px rgba(201, 162, 39, .16), 0 0 20px 4px rgba(232, 54, 143, .2);
  }
  50% {
    box-shadow: 0 0 0 6px var(--ink-deep), 0 0 0 19px rgba(201, 162, 39, .07), 0 0 30px 10px rgba(232, 54, 143, .34);
  }
}

.page-about .version__body {
  grid-column: 2;
  min-width: 0;
}

.page-about .version__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(34px, 7vw, 62px);
  font-weight: 700;
  line-height: .92;
  letter-spacing: -0.02em;
  color: rgba(201, 162, 39, .38);
}

.page-about .version--v4 .version__num {
  color: var(--gold);
}

.page-about .version h3 {
  font-family: var(--font-display);
  font-size: clamp(19px, 2.3vw, 25px);
  line-height: 1.36;
  color: var(--paper);
  margin: 8px 0 12px;
}

.page-about .version p {
  color: rgba(244, 238, 227, .76);
  font-size: 16px;
  line-height: 1.78;
  max-width: 36em;
  margin: 0 0 12px;
}

.page-about .version__media {
  margin: 22px 0 0;
  max-width: 34em;
}

.page-about .annot {
  border-left: 2px solid rgba(231, 214, 164, .42);
  padding: 4px 0 4px 16px;
  margin-top: 20px;
  max-width: 34em;
}

.page-about .annot__sum {
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--cyan);
  cursor: pointer;
  list-style: none;
}

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

.page-about .annot__sum::before {
  content: "＋ ";
  color: var(--gold);
}

.page-about .annot[open] .annot__sum::before {
  content: "－ ";
}

.page-about .annot p {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  margin: 10px 0 0;
}

/* ---------- 服务范围 ---------- */
.page-about .coverage {
  display: grid;
  gap: 34px;
  margin-bottom: clamp(56px, 9vw, 108px);
}

.page-about .coverage__grid {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid rgba(231, 214, 164, .16);
  border-radius: 22px;
  background: linear-gradient(160deg, rgba(18, 48, 40, .9), rgba(6, 17, 14, .9));
  padding: 12px;
}

.page-about .coverage__caption {
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--muted);
  margin: 12px 0 0;
  max-width: 30em;
}

.page-about .coverage__stats {
  list-style: none;
  margin: 26px 0 0;
  padding: 22px 0 0;
  border-top: var(--rule);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 16px;
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(21px, 3.4vw, 30px);
  line-height: 1.15;
  color: var(--gold);
  letter-spacing: -0.01em;
}

.page-about .stat-label {
  display: block;
  font-size: 12.5px;
  letter-spacing: .05em;
  color: var(--muted);
  margin-top: 6px;
}

.page-about .city-band {
  margin: 0 0 clamp(56px, 9vw, 108px);
}

/* ---------- 运营与维护 ---------- */
.page-about .upkeep {
  margin-bottom: clamp(56px, 9vw, 108px);
}

.page-about .cadence {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--rule);
}

.page-about .cadence__item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 20px 0;
  border-bottom: var(--rule);
}

.page-about .cadence__key {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .14em;
  color: var(--gold-sand);
}

.page-about .cadence__item p {
  margin: 0;
  color: rgba(244, 238, 227, .76);
  font-size: 15.5px;
  line-height: 1.78;
  max-width: 40em;
}

/* ---------- 与会员中心的分工 ---------- */
.page-about .relation {
  margin-bottom: clamp(56px, 9vw, 108px);
}

.page-about .relation__lead {
  margin-bottom: 34px;
}

.page-about .relation__paths {
  display: grid;
  gap: 12px;
}

.page-about .path-card {
  display: block;
  text-decoration: none;
  padding: 20px 20px 22px;
  border: 1px solid rgba(231, 214, 164, .2);
  border-radius: 6px 22px 6px 22px;
  background: linear-gradient(150deg, rgba(18, 48, 40, .82), rgba(6, 17, 14, .82));
  transition: border-color var(--ease), background-color var(--ease);
}

.page-about .path-card:hover,
.page-about .path-card:focus-visible {
  border-color: var(--gold);
}

.page-about .path-card__key {
  display: block;
  font-size: 11.5px;
  letter-spacing: .16em;
  color: var(--cyan);
  margin-bottom: 8px;
}

.page-about .path-card__title {
  display: block;
  font-family: var(--font-display);
  font-size: 19px;
  color: var(--paper);
  margin-bottom: 8px;
}

.page-about .path-card__desc {
  display: block;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 收藏引导 ---------- */
.page-about .keep {
  padding: clamp(30px, 5vw, 48px) 0 0;
  border-top: 1px solid rgba(201, 162, 39, .4);
}

.page-about .keep__list {
  list-style: none;
  margin: 18px 0 26px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .keep__list li {
  position: relative;
  padding-left: 20px;
  color: rgba(244, 238, 227, .8);
  font-size: 15.5px;
  line-height: 1.75;
  max-width: 38em;
}

.page-about .keep__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .68em;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gold);
  opacity: .8;
}

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

/* ---------- 桌面端 ---------- */
@media (min-width: 900px) {
  .page-about {
    --about-rail: 84px;
  }

  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
    gap: 52px;
  }

  .page-about .about-hero__media {
    margin-bottom: -22px;
  }

  .page-about .version {
    column-gap: 32px;
  }

  .page-about .version::before {
    left: 41px;
  }

  .page-about .coverage {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 56px;
    align-items: center;
  }

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

  .page-about .cadence__item {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 24px;
    padding: 24px 0;
  }

  .page-about .relation {
    display: grid;
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .relation__lead {
    margin-bottom: 0;
  }
}

@media (min-width: 1140px) {
  .page-about .relation__paths {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }

  .page-about .path-card:first-child {
    grid-column: 1 / -1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .version--v4 .version__dot {
    animation: none;
    box-shadow: 0 0 0 6px var(--ink-deep), 0 0 0 14px rgba(201, 162, 39, .14);
  }
}
<<<END>>>