.page-about {
  --about-rail: 300px;
  --about-rule: rgba(22, 40, 60, .14);
  --about-tint: rgba(22, 40, 60, .045);
  --about-amber-tint: rgba(208, 138, 44, .10);
  background: var(--paper);
  color: var(--text);
  font-family: var(--font-sans);
  overflow-x: clip;
}

.page-about .container {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding-top: clamp(20px, 3vw, 34px);
  font-family: var(--font-mono);
  font-size: 13px;
}

.page-about .breadcrumb__list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  color: var(--rock);
}

.page-about .breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: 8px;
  color: var(--rock);
}

.page-about .breadcrumb__link {
  color: var(--ink-blue);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 180ms var(--ease), color 180ms var(--ease);
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-bottom: clamp(44px, 7vw, 88px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(30px, 5vw, 52px);
  align-items: start;
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .about-hero__lead h1 {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(32px, 6.2vw, 70px);
  line-height: 1.16;
  letter-spacing: -.01em;
  margin: 12px 0 0;
  color: var(--ink-blue);
}

.page-about .about-hero__lead .lede {
  margin: 20px 0 0;
  max-width: 46ch;
  font-size: clamp(16px, 1.6vw, 17px);
  line-height: 1.85;
  color: #35414e;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero__panel {
  background: var(--ink-blue);
  color: var(--paper);
  padding: 26px 24px 24px;
  clip-path: polygon(0 0, calc(100% - var(--cut-md)) 0, 100% var(--cut-md), 100% 100%, 0 100%);
}

.page-about .about-hero__panel-title {
  margin: 0 0 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--amber-soft);
}

.page-about .coord-list {
  margin: 0;
  display: grid;
  gap: 0;
}

.page-about .coord-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 0;
  border-top: 1px solid var(--line-paper);
}

.page-about .coord-row:last-child {
  border-bottom: 1px solid var(--line-paper);
}

.page-about .coord-label {
  font-size: 14px;
  color: rgba(247, 242, 232, .68);
  white-space: nowrap;
}

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

.page-about .coord-num {
  font-family: var(--font-mono);
  font-size: 20px;
  color: var(--amber);
  margin-right: 2px;
}

.page-about .about-hero__panel-note {
  margin: 18px 0 0;
  font-size: 13px;
  line-height: 1.75;
  color: rgba(247, 242, 232, .6);
}

/* ---------- 通用章节头 ---------- */
.page-about .section-head {
  max-width: 62ch;
  margin-bottom: clamp(28px, 4vw, 48px);
}

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

.page-about .section-head h2 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(25px, 3.4vw, 40px);
  line-height: 1.28;
  color: var(--ink-blue);
}

.page-about .section-head > p:last-child {
  margin: 16px 0 0;
  font-size: 17px;
  line-height: 1.85;
  color: #3b4753;
}

/* ---------- 编年 ---------- */
.page-about .about-chrono {
  border-top: 1px solid var(--about-rule);
  padding-top: clamp(36px, 5vw, 64px);
}

.page-about .about-chrono__layout {
  display: grid;
  gap: clamp(28px, 4vw, 50px);
}

.page-about .about-chrono__rail {
  display: flex;
  flex-direction: column;
  gap: 26px;
}

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

.page-about .about-chrono__figure .media-frame {
  max-width: 320px;
}

.page-about .media-caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--rock);
}

.page-about .chrono-nav__label {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--rock);
  text-transform: uppercase;
}

.page-about .chrono-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .chrono-nav__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--about-rule);
  border-left: 2px solid var(--clay);
  font-size: 13px;
  color: var(--ink-blue);
  text-decoration: none;
  background: rgba(255, 255, 255, .45);
  transition: transform 180ms var(--ease), border-color 180ms var(--ease), background-color 180ms var(--ease);
}

.page-about .chrono-nav__link:hover,
.page-about .chrono-nav__link:focus-visible {
  transform: translateY(-2px);
  border-left-color: var(--amber);
  background: var(--about-amber-tint);
}

.page-about .chrono-nav__year {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--clay);
}

.page-about .chrono-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(30px, 4vw, 54px);
}

.page-about .chrono-item {
  position: relative;
  padding: 4px 0 2px 26px;
  border-left: 1px solid var(--about-rule);
  transition: background-color 220ms var(--ease), border-color 220ms var(--ease);
}

.page-about .chrono-item::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 14px;
  width: 14px;
  height: 1px;
  background: var(--clay);
  transform: rotate(-38deg);
  transform-origin: left center;
}

.page-about .chrono-item:target {
  border-left-color: var(--amber);
  background: var(--about-amber-tint);
}

.page-about .chrono-item__year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: .08em;
  color: var(--clay);
}

.page-about .chrono-item__title {
  margin: 8px 0 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(20px, 2.4vw, 26px);
  line-height: 1.4;
  color: var(--ink-blue);
}

.page-about .chrono-item__text {
  margin: 12px 0 0;
  font-size: 16px;
  line-height: 1.85;
  color: #3b4753;
  max-width: 62ch;
}

.page-about .chrono-item__text a {
  color: var(--ink-blue);
  text-decoration: none;
  border-bottom: 1px solid var(--amber);
  transition: color 160ms var(--ease);
}

.page-about .chrono-item__text a:hover,
.page-about .chrono-item__text a:focus-visible {
  color: var(--clay);
}

.page-about .chrono-item__impact {
  margin: 14px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--moss);
  font-size: 14px;
  line-height: 1.8;
  color: var(--moss);
  max-width: 60ch;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  border-top: 1px solid var(--about-rule);
}

.page-about .team-grid {
  display: grid;
  gap: 18px;
}

.page-about .team-card {
  background: var(--about-tint);
  padding: 24px 22px 26px;
  border-top: 3px solid var(--ink-blue);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut-md)), calc(100% - var(--cut-md)) 100%, 0 100%);
  transition: transform 200ms var(--ease), border-color 200ms var(--ease), background-color 200ms var(--ease);
}

.page-about .team-card:hover,
.page-about .team-card:focus-visible,
.page-about .team-card:focus-within {
  transform: translateY(-2px);
  border-top-color: var(--amber);
  background: var(--about-amber-tint);
}

.page-about .team-card:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 2px;
}

.page-about .team-card__index {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--clay);
}

.page-about .team-card__title {
  margin: 12px 0 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 22px;
  color: var(--ink-blue);
}

.page-about .team-card__text {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: #3b4753;
}

.page-about .team-card__detail {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: #4c5863;
}

/* ---------- 校对 ---------- */
.page-about .about-proof {
  background: var(--ink-blue);
  color: var(--paper);
  padding: clamp(44px, 6vw, 88px) 0;
  margin-top: clamp(40px, 6vw, 72px);
}

.page-about .about-proof .section-head__index {
  color: var(--amber-soft);
}

.page-about .about-proof .section-head h2 {
  color: var(--paper);
}

.page-about .about-proof .section-head > p:last-child {
  color: rgba(247, 242, 232, .74);
}

.page-about .proof-figure {
  margin: 0 0 clamp(28px, 4vw, 44px);
}

.page-about .about-proof .media-caption {
  color: rgba(247, 242, 232, .6);
}

.page-about .proof-list {
  border-bottom: 1px solid var(--line-paper);
}

.page-about .proof-item {
  border-top: 1px solid var(--line-paper);
}

.page-about .proof-item__summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 18px;
  padding: 18px 0;
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1.6;
  color: var(--paper);
  transition: color 180ms var(--ease);
}

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

.page-about .proof-item__summary::after {
  content: "+";
  flex: none;
  font-size: 18px;
  color: var(--amber);
  transition: transform 200ms var(--ease);
}

.page-about .proof-item[open] .proof-item__summary::after {
  content: "–";
  transform: translateY(-1px);
}

.page-about .proof-item__summary:hover,
.page-about .proof-item__summary:focus-visible {
  color: var(--amber-soft);
}

.page-about .proof-item__body {
  padding: 0 0 20px;
  max-width: 68ch;
}

.page-about .proof-item__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(247, 242, 232, .82);
}

/* ---------- 服务范围 ---------- */
.page-about .about-reach {
  padding-top: clamp(44px, 6vw, 84px);
}

.page-about .about-reach__grid {
  display: grid;
  gap: clamp(28px, 4vw, 52px);
  align-items: start;
}

.page-about .about-reach__lead h2 {
  margin: 10px 0 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(25px, 3.4vw, 40px);
  line-height: 1.28;
  color: var(--ink-blue);
}

.page-about .about-reach__lead p {
  margin: 16px 0 0;
  font-size: 16px;
  line-height: 1.85;
  color: #3b4753;
  max-width: 58ch;
}

.page-about .about-reach__lead p a {
  color: var(--ink-blue);
  text-decoration: none;
  border-bottom: 1px solid var(--amber);
}

.page-about .about-reach__lead p a:hover,
.page-about .about-reach__lead p a:focus-visible {
  color: var(--clay);
}

.page-about .reach-stats {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}

.page-about .reach-stat {
  border-left: 3px solid var(--steel);
  padding: 6px 0 6px 16px;
}

.page-about .reach-stat__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 30px);
  color: var(--ink-blue);
  line-height: 1.2;
}

.page-about .reach-stat__label {
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--rock) !important;
}

.page-about .reach-figure {
  margin: 0;
}

/* ---------- 联络 ---------- */
.page-about .about-contact {
  background: var(--ink-deep);
  color: var(--paper);
  padding: clamp(44px, 6vw, 84px) 0;
  margin-top: clamp(44px, 6vw, 84px);
}

.page-about .about-contact__grid {
  display: grid;
  gap: clamp(28px, 4vw, 56px);
}

.page-about .about-contact__lead .eyebrow {
  color: var(--amber-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
}

.page-about .about-contact__lead h2 {
  margin: 10px 0 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(25px, 3.4vw, 38px);
  line-height: 1.3;
  color: var(--paper);
}

.page-about .about-contact__lead p {
  margin: 16px 0 0;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(247, 242, 232, .78);
  max-width: 52ch;
}

.page-about .about-contact__lead .btn {
  margin-top: 26px;
}

.page-about .about-contact__info {
  border-top: 1px solid var(--line-paper);
  padding-top: 22px;
}

.page-about .about-contact__info .contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-contact__info .contact-row {
  display: grid;
  gap: 4px;
}

.page-about .about-contact__info .contact-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--amber-soft);
}

.page-about .about-contact__info .contact-value {
  font-size: 15px;
  line-height: 1.75;
  color: var(--paper);
  word-break: break-word;
}

.page-about .about-contact__info .contact-hours {
  margin: 22px 0 0;
  font-size: 13px;
  line-height: 1.8;
  color: rgba(247, 242, 232, .64);
}

/* ---------- 备案横条 ---------- */
.page-about .about-filing {
  background: var(--paper);
  border-top: 1px solid var(--about-rule);
}

.page-about .about-filing__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 22px 0 26px;
}

.page-about .about-filing__text {
  margin: 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--rock);
}

.page-about .about-filing__stamp {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--clay);
  border: 1px solid var(--clay);
  padding: 4px 10px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .team-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .reach-stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about .about-contact__info .contact-row {
    grid-template-columns: 74px 1fr;
    gap: 14px;
    align-items: baseline;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: 7fr 5fr;
    gap: clamp(32px, 5vw, 76px);
  }

  .page-about .about-chrono__layout {
    grid-template-columns: var(--about-rail) 1fr;
    gap: clamp(36px, 5vw, 72px);
  }

  .page-about .chrono-nav {
    position: sticky;
    top: 96px;
  }

  .page-about .chrono-nav__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 6px;
  }

  .page-about .chrono-nav__link {
    width: 100%;
    justify-content: flex-start;
  }

  .page-about .about-reach__grid {
    grid-template-columns: 7fr 5fr;
    gap: clamp(32px, 5vw, 68px);
  }

  .page-about .about-contact__grid {
    grid-template-columns: 7fr 5fr;
    gap: clamp(32px, 5vw, 68px);
  }
}

@media (hover: hover) and (min-width: 760px) {
  .page-about .team-card__detail {
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }

  .page-about .team-card:hover .team-card__detail,
  .page-about .team-card:focus-visible .team-card__detail,
  .page-about .team-card:focus-within .team-card__detail {
    -webkit-line-clamp: 5;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .chrono-nav__link,
  .page-about .team-card,
  .page-about .chrono-item,
  .page-about .proof-item__summary::after {
    transition: none;
  }

  .page-about .chrono-nav__link:hover,
  .page-about .team-card:hover {
    transform: none;
  }
}