.page-about {
  --about-paper-line: rgba(74, 90, 105, .28);
  --about-paper-line-strong: rgba(74, 90, 105, .5);
  background: var(--ink);
}

.page-about .breadcrumb {
  padding-top: 22px;
  padding-bottom: 6px;
}

.page-about .breadcrumb a,
.page-about .breadcrumb li {
  color: var(--slate);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 34px 0 52px;
  border-bottom: 1px solid var(--line-strong);
  background:
    radial-gradient(130% 100% at 90% 0%, rgba(62, 122, 120, .3) 0%, rgba(11, 26, 43, 0) 58%),
    linear-gradient(180deg, var(--ink) 0%, var(--ink-soft) 100%);
}

.page-about .about-hero__inner {
  display: grid;
  gap: 34px;
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-size: clamp(30px, 6.4vw, 58px);
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--paper);
  margin: 14px 0 18px;
  max-width: 18em;
}

.page-about .about-hero__intro {
  font-size: 16px;
  line-height: 1.85;
  color: rgba(245, 241, 232, .8);
  max-width: 42em;
  margin: 0 0 26px;
}

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

.page-about .about-record {
  border: 1px solid var(--line-strong);
  border-top: 3px solid var(--gold);
  background: rgba(245, 241, 232, .04);
  padding: 20px 20px 14px;
}

.page-about .about-record__title {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--gold);
  margin: 0 0 14px;
}

.page-about .about-record__list {
  margin: 0;
}

.page-about .about-record__row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 14px;
  padding: 9px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-record__row:last-child {
  border-bottom: 0;
}

.page-about .about-record__row dt {
  font-size: 13.5px;
  color: var(--slate);
  letter-spacing: .02em;
}

.page-about .about-record__row dd {
  margin: 0;
  font-size: 15px;
  color: var(--paper);
  text-align: right;
}

/* ---------- 沿革区 ---------- */
.page-about .about-chronicle {
  background: var(--paper);
  color: var(--ink);
  padding: 52px 0 68px;
}

.page-about .about-chronicle__inner {
  display: grid;
  gap: 26px;
}

.page-about .about-axis__title {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--slate-deep);
  margin: 0 0 10px;
}

.page-about .about-axis__list {
  display: flex;
  gap: 20px;
  overflow-x: auto;
  margin: 0;
  padding: 0 0 10px;
  list-style: none;
  border-bottom: 1px solid var(--about-paper-line);
}

.page-about .about-axis__list a {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--slate-deep);
  text-decoration: none;
  white-space: nowrap;
  border-bottom: 1px solid transparent;
  padding-bottom: 3px;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

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

.page-about .about-sec h2,
.page-about .about-phases h2 {
  font-family: var(--font-head);
  font-size: clamp(24px, 4.6vw, 38px);
  line-height: 1.24;
  letter-spacing: -.01em;
  color: var(--ink);
  margin: 12px 0 18px;
}

.page-about .about-sec__lede {
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--ink-soft);
  max-width: 40em;
  margin: 0 0 22px;
}

.page-about .about-sec p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-soft);
  max-width: 40em;
}

.page-about .about-figure {
  margin: 22px 0;
  border: 1px solid var(--about-paper-line-strong);
  background: var(--apricot);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-figure .media__caption {
  font-size: 13px;
  line-height: 1.7;
  color: var(--slate-deep);
  padding: 10px 14px 12px;
  border-top: 1px solid var(--about-paper-line);
  background: rgba(233, 217, 188, .5);
}

/* ---------- 阶段 ---------- */
.page-about .about-phases__head p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-soft);
  max-width: 42em;
  margin: 0;
}

.page-about .phase-list {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
}

.page-about .phase {
  position: relative;
  border-top: 1px solid var(--about-paper-line-strong);
  padding: 26px 0 8px;
  margin-bottom: 22px;
}

.page-about .phase::before {
  content: "";
  position: absolute;
  top: -4px;
  left: 0;
  width: 7px;
  height: 7px;
  background: var(--gold);
  transform: rotate(45deg);
  transition: background .24s var(--ease);
}

.page-about .phase:hover::before {
  background: var(--cinnabar);
}

.page-about .phase__no {
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--slate-deep);
  margin: 0 0 10px;
}

.page-about .phase__title {
  font-family: var(--font-head);
  font-size: 20px;
  line-height: 1.42;
  font-weight: 600;
  color: var(--ink);
  margin: 0 0 10px;
}

.page-about .phase__desc {
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--ink-soft);
  max-width: 40em;
  margin: 0 0 14px;
}

.page-about .phase-note {
  border-left: 2px solid var(--gold);
  background: rgba(201, 162, 75, .1);
  padding: 11px 15px;
  max-width: 40em;
}

.page-about .phase-note summary {
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--slate-deep);
}

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

.page-about .phase-note summary::after {
  content: " +";
  color: var(--cinnabar);
}

.page-about .phase-note[open] summary::after {
  content: " −";
  color: var(--cinnabar);
}

.page-about .phase-note p {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* ---------- 四类内容 ---------- */
.page-about .about-map {
  background: linear-gradient(180deg, var(--paper) 0%, #efe6d5 100%);
  color: var(--ink);
  padding: 56px 0 60px;
  border-top: 1px solid var(--about-paper-line);
}

.page-about .about-map__head h2 {
  font-family: var(--font-head);
  font-size: clamp(24px, 4.6vw, 38px);
  line-height: 1.24;
  color: var(--ink);
  margin: 12px 0 14px;
}

.page-about .about-map__head p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-soft);
  max-width: 42em;
  margin: 0 0 26px;
}

.page-about .about-rail {
  display: flex;
  gap: 18px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding: 2px 0 18px;
  margin: 0;
  list-style: none;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__item {
  flex: 0 0 84%;
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--about-paper-line-strong);
  border-top: 3px solid var(--gold);
  background: var(--paper);
  padding: 20px 18px 18px;
}

.page-about .about-rail__no {
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--cinnabar);
  margin: 0 0 12px;
}

.page-about .about-rail__title {
  font-family: var(--font-head);
  font-size: 19px;
  line-height: 1.4;
  font-weight: 600;
  color: var(--ink);
  margin: 0 0 10px;
}

.page-about .about-rail__desc {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin: 0 0 18px;
  flex: 1 1 auto;
}

.page-about .about-rail__link {
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--cinnabar);
  text-decoration: none;
  border-bottom: 1px solid var(--cinnabar);
  padding-bottom: 3px;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

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

/* ---------- 团队 ---------- */
.page-about .about-team {
  background: var(--ink);
  color: var(--paper);
  padding: 56px 0 72px;
  border-top: 1px solid var(--line);
}

.page-about .about-team__head h2 {
  font-family: var(--font-head);
  font-size: clamp(24px, 4.6vw, 38px);
  line-height: 1.24;
  color: var(--paper);
  margin: 12px 0 14px;
}

.page-about .about-team__head p {
  font-size: 16px;
  line-height: 1.85;
  color: rgba(245, 241, 232, .76);
  max-width: 42em;
  margin: 0 0 26px;
}

.page-about .about-flowline {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  list-style: none;
  margin: 0 0 34px;
  padding: 0;
  border-top: 1px solid var(--line-strong);
}

.page-about .about-flowline li {
  flex: 1 1 130px;
  border-bottom: 2px solid var(--jade);
  padding: 12px 10px 10px 0;
  font-size: 13.5px;
  color: rgba(245, 241, 232, .82);
}

.page-about .about-flowline .mono {
  color: var(--gold);
  margin-right: 6px;
}

.page-about .team-list {
  display: grid;
  gap: 0;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .team-item {
  border-top: 1px solid var(--line-strong);
  padding: 20px 0 8px;
}

.page-about .team-item h3 {
  font-family: var(--font-head);
  font-size: 20px;
  line-height: 1.4;
  color: var(--gold-bright);
  margin: 0 0 10px;
}

.page-about .team-item p {
  font-size: 15px;
  line-height: 1.85;
  color: rgba(245, 241, 232, .78);
  max-width: 38em;
  margin: 0 0 14px;
}

/* ---------- 维护与体量 ---------- */
.page-about .about-upkeep {
  background: var(--paper);
  color: var(--ink);
  padding: 56px 0 64px;
}

.page-about .about-upkeep__head h2 {
  font-family: var(--font-head);
  font-size: clamp(24px, 4.6vw, 38px);
  line-height: 1.24;
  color: var(--ink);
  margin: 12px 0 14px;
}

.page-about .about-upkeep__head p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-soft);
  max-width: 42em;
  margin: 0 0 28px;
}

.page-about .upkeep-grid {
  display: grid;
  gap: 32px;
}

.page-about .upkeep-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--about-paper-line-strong);
}

.page-about .upkeep-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--about-paper-line);
}

.page-about .upkeep-item__num {
  font-size: 17px;
  letter-spacing: .04em;
  color: var(--cinnabar);
  margin: 0;
}

.page-about .upkeep-item__text {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin: 0;
  max-width: 34em;
}

.page-about .about-coverage {
  background: var(--apricot);
  border-left: 3px solid var(--jade);
  padding: 22px 20px 14px;
}

.page-about .about-coverage__title {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .12em;
  color: var(--slate-deep);
  margin: 0 0 10px;
}

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

.page-about .stat-list li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 12px 0;
  border-bottom: 1px solid rgba(74, 90, 105, .2);
}

.page-about .stat-list li:last-child {
  border-bottom: 0;
}

.page-about .stat-num {
  flex: 0 0 auto;
  min-width: 2.4em;
  font-size: 24px;
  line-height: 1;
  color: var(--ink);
}

.page-about .stat-label {
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--ink-soft);
}

/* ---------- 属地与联络 ---------- */
.page-about .about-region {
  background: var(--ink-soft);
  color: var(--paper);
  padding: 54px 0 66px;
  border-top: 1px solid var(--line);
}

.page-about .about-region__inner {
  display: grid;
  gap: 30px;
}

.page-about .about-region__figure {
  border: 1px solid var(--line-strong);
  background: var(--ink);
}

.page-about .about-region__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-region__figure .media__caption {
  font-size: 13px;
  line-height: 1.7;
  color: var(--slate);
  padding: 10px 14px 12px;
  border-top: 1px solid var(--line);
}

.page-about .about-region h2 {
  font-family: var(--font-head);
  font-size: clamp(24px, 4.6vw, 34px);
  line-height: 1.26;
  color: var(--paper);
  margin: 12px 0 16px;
}

.page-about .about-region__info > p {
  font-size: 15.5px;
  line-height: 1.85;
  color: rgba(245, 241, 232, .78);
  max-width: 38em;
  margin: 0 0 22px;
}

.page-about .contact-list {
  margin: 0 0 20px;
  border-top: 1px solid var(--line-strong);
}

.page-about .contact-row {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .contact-row dt {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--gold);
}

.page-about .contact-row dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--paper);
  word-break: break-word;
}

.page-about .about-region__note {
  font-size: 14px;
  line-height: 1.8;
  color: var(--slate) !important;
  margin: 0 0 20px !important;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero {
    padding: 44px 0 64px;
  }

  .page-about .about-rail__item {
    flex: 0 0 46%;
  }

  .page-about .about-flowline li {
    flex: 1 1 0;
    border-bottom-width: 2px;
  }

  .page-about .contact-row {
    flex-direction: row;
    align-items: baseline;
    gap: 18px;
  }

  .page-about .contact-row dt {
    flex: 0 0 96px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    gap: 48px;
    align-items: start;
  }

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

  .page-about .team-list {
    grid-template-columns: 1fr 1fr;
    column-gap: 48px;
  }

  .page-about .team-item:nth-child(even) {
    margin-top: 46px;
  }

  .page-about .upkeep-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .about-region__inner {
    grid-template-columns: minmax(0, .8fr) minmax(0, 1.2fr);
    gap: 44px;
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .about-chronicle {
    padding: 64px 0 80px;
  }

  .page-about .about-chronicle__inner {
    grid-template-columns: 128px minmax(0, 1fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-axis {
    position: sticky;
    top: 104px;
  }

  .page-about .about-axis__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    border-bottom: 0;
    border-left: 1px solid var(--about-paper-line-strong);
    padding: 0;
  }

  .page-about .about-axis__list li {
    position: relative;
    padding: 13px 0 13px 16px;
  }

  .page-about .about-axis__list li::before {
    content: "";
    position: absolute;
    left: -3.5px;
    top: 50%;
    width: 6px;
    height: 6px;
    background: var(--slate-deep);
    transform: translateY(-50%) rotate(45deg);
    transition: background .24s var(--ease);
  }

  .page-about .about-axis__list li:hover::before {
    background: var(--gold);
  }

  .page-about .about-sec,
  .page-about .about-phases {
    max-width: 840px;
  }

  .page-about .about-rail__item {
    flex: 0 0 31%;
  }

  .page-about .phase__title {
    font-size: 22px;
  }
}

@media (min-width: 1280px) {
  .page-about .about-hero h1 {
    letter-spacing: -.025em;
  }

  .page-about .about-rail__item {
    flex: 0 0 29%;
  }

  .page-about .about-figure--wide {
    max-width: 900px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-axis__list a,
  .page-about .phase::before,
  .page-about .about-rail__link,
  .page-about .about-axis__list li::before {
    transition: none;
  }
}