.page-about {
  --about-rule: rgba(138, 90, 43, 0.22);
  --about-rule-light: rgba(216, 176, 122, 0.24);
  background: var(--paper-100);
  color: var(--ink-900);
  font-family: var(--font-body);
  line-height: 1.85;
}

.page-about a:not(.btn) {
  color: var(--brass-700);
  text-underline-offset: 3px;
}

.page-about a:not(.btn):focus-visible,
.page-about button:focus-visible {
  outline: 2px solid var(--celadon-500);
  outline-offset: 3px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 26px 20px 52px;
  background:
    radial-gradient(120% 85% at 92% -8%, rgba(185, 133, 74, 0.34), transparent 58%),
    linear-gradient(158deg, var(--ink-900) 4%, var(--ink-700) 100%);
  color: var(--paper-100);
  border-bottom-left-radius: var(--radius-lg);
  border-bottom-right-radius: var(--radius-lg);
}

.page-about .about-hero__inner {
  max-width: var(--shell-max);
  margin: 0 auto;
}

.page-about .about-hero .crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: rgba(243, 235, 221, 0.62);
}

.page-about .about-hero .crumbs a {
  color: var(--brass-300);
  text-decoration: none;
}

.page-about .about-hero .crumbs a:hover {
  text-decoration: underline;
}

.page-about .about-hero__kicker {
  margin: 30px 0 0;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--brass-300);
}

.page-about .about-hero h1 {
  margin: 12px 0 0;
  max-width: 17ch;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.28;
  font-size: clamp(1.9rem, 7vw, 3.5rem);
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.9;
  color: rgba(243, 235, 221, 0.84);
}

.page-about .about-hero__stats {
  list-style: none;
  margin: 34px 0 0;
  padding: 22px 0 0;
  border-top: 1px solid var(--about-rule-light);
  display: grid;
  gap: 18px;
}

.page-about .about-stat__num {
  display: block;
  font-size: 21px;
  letter-spacing: 0.06em;
  color: var(--brass-300);
}

.page-about .about-stat__k {
  display: block;
  margin-top: 4px;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(243, 235, 221, 0.68);
}

/* ---------- 章节索引 ---------- */
.page-about .chapter-index {
  position: relative;
  z-index: 2;
  margin-top: -22px;
  padding: 0 20px;
}

.page-about .chapter-index__list {
  list-style: none;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  max-width: var(--shell-max);
  margin: 0 auto;
  padding: 0 0 6px;
  scrollbar-width: none;
}

.page-about .chapter-index__list::-webkit-scrollbar {
  display: none;
}

.page-about .chapter-index__list a {
  display: inline-block;
  white-space: nowrap;
  padding: 9px 16px;
  border-radius: 999px;
  border: 1px solid var(--about-rule);
  background: var(--paper-100);
  box-shadow: 0 6px 18px rgba(11, 27, 43, 0.06);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--brass-700);
  text-decoration: none;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.page-about .chapter-index__list a:hover,
.page-about .chapter-index__list a:focus-visible {
  background: var(--ink-900);
  border-color: var(--ink-900);
  color: var(--paper-100);
}

/* ---------- 通用分区 ---------- */
.page-about .about-section {
  padding: 56px 20px;
  scroll-margin-top: calc(var(--bar-h) + 24px);
}

.page-about .about-section > .shell {
  max-width: var(--shell-max);
  margin: 0 auto;
  padding: 0;
}

.page-about .about-section--deep {
  background: linear-gradient(180deg, var(--ink-900) 0%, var(--ink-700) 100%);
  color: var(--paper-100);
  border-radius: var(--radius-lg);
  margin: 0 12px;
}

.page-about .about-head {
  display: grid;
  gap: 14px;
  margin-bottom: 36px;
}

.page-about .about-head__idx {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--brass-500);
}

.page-about .about-head__title {
  margin: 0;
  max-width: 22ch;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.32;
  font-size: clamp(1.5rem, 4.6vw, 2.25rem);
}

.page-about .about-head__lede {
  margin: 0;
  max-width: 62ch;
  font-size: 16px;
  color: var(--slate-600);
}

.page-about .about-section--deep .about-head__lede,
.page-about .about-section--deep .hall__body p {
  color: rgba(243, 235, 221, 0.82);
}

/* ---------- 时间轴 ---------- */
.page-about .about-lineage {
  display: grid;
  gap: 32px;
}

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

.page-about .timeline__item {
  position: relative;
  margin-left: 6px;
  padding: 0 0 30px 28px;
  border-left: 1px solid var(--about-rule);
}

.page-about .timeline__item:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 10px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--brass-500);
  box-shadow: 0 0 0 4px var(--paper-100);
}

.page-about .timeline__year {
  margin: 0;
  font-size: 14px;
  letter-spacing: 0.14em;
  color: var(--brass-700);
}

.page-about .timeline__title {
  margin: 6px 0 8px;
  font-family: var(--font-display);
  font-size: 1.16rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  line-height: 1.45;
}

.page-about .timeline__text {
  margin: 0;
  max-width: 58ch;
  font-size: 15.5px;
  color: var(--slate-600);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--paper-200);
}

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

.page-about .about-figure figcaption {
  padding: 12px 18px 15px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--slate-600);
  background: var(--paper-100);
}

.page-about .about-section--deep .about-figure figcaption {
  background: transparent;
  color: rgba(243, 235, 221, 0.62);
}

.page-about .about-figure--halls,
.page-about .about-figure--network {
  margin-top: 30px;
}

/* ---------- 四厅 ---------- */
.page-about .halls {
  display: grid;
}

.page-about .hall {
  display: grid;
  gap: 10px;
  padding: 24px 0;
  border-top: 1px solid var(--about-rule-light);
}

.page-about .hall:first-child {
  border-top: 0;
  padding-top: 4px;
}

.page-about .hall__num {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--brass-300);
}

.page-about .hall__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 1.14rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  line-height: 1.5;
  color: var(--paper-100);
}

.page-about .hall__body p {
  margin: 0;
  max-width: 58ch;
  font-size: 15.5px;
}

/* ---------- 团队 ---------- */
.page-about .team {
  display: grid;
  gap: 10px;
}

.page-about .team-fold {
  border: 1px solid var(--about-rule);
  border-radius: var(--radius-md);
  background: #FBF6EC;
  overflow: hidden;
}

.page-about .team-fold__trigger {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  border: 0;
  background: transparent;
  font-family: inherit;
  color: var(--ink-900);
  text-align: left;
  cursor: pointer;
  transition: background var(--dur) var(--ease);
}

.page-about .team-fold__trigger:hover {
  background: rgba(185, 133, 74, 0.09);
}

.page-about .team-fold__num {
  min-width: 24px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--brass-700);
}

.page-about .team-fold__name {
  flex: 1;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.02rem;
  letter-spacing: 0.03em;
}

.page-about .team-fold__count {
  font-size: 13px;
  color: var(--slate-600);
}

.page-about .team-fold__trigger::after {
  content: "";
  width: 7px;
  height: 7px;
  margin-left: 4px;
  border-right: 2px solid var(--brass-500);
  border-bottom: 2px solid var(--brass-500);
  transform: rotate(45deg);
  transition: transform var(--dur) var(--ease);
}

.page-about .team-fold__trigger[aria-expanded="true"]::after {
  transform: rotate(-135deg);
}

.page-about .team-fold .fold__inner {
  padding: 0 18px 18px;
  font-size: 15px;
  color: var(--slate-600);
}

.page-about .team-fold .fold__inner p {
  margin: 0;
  max-width: 60ch;
}

.page-about .review-note {
  margin-top: 26px;
  padding: 20px 22px;
  border-left: 3px solid var(--celadon-500);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: var(--celadon-100);
}

.page-about .review-note__idx {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--celadon-500);
}

.page-about .review-note p {
  margin: 0;
  max-width: 60ch;
  font-size: 15px;
  color: var(--slate-600);
}

/* ---------- 合作生态 ---------- */
.page-about .network {
  display: grid;
  gap: 28px;
}

.page-about .network__stats {
  display: grid;
  align-content: start;
}

.page-about .network-stat {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 16px;
  align-items: baseline;
  padding: 16px 0;
  border-bottom: 1px solid var(--about-rule-light);
}

.page-about .network-stat:first-child {
  padding-top: 4px;
}

.page-about .network-stat span {
  font-size: 25px;
  letter-spacing: 0.04em;
  color: var(--brass-300);
}

.page-about .network-stat p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: rgba(243, 235, 221, 0.8);
}

.page-about .coop {
  display: grid;
  gap: 26px;
  margin-top: 34px;
}

.page-about .coop h3 {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--paper-100);
}

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

.page-about .coop__list li {
  position: relative;
  padding-left: 16px;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(243, 235, 221, 0.8);
}

.page-about .coop__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--brass-500);
}

.page-about .coop__list strong {
  font-weight: 600;
  color: var(--paper-100);
}

.page-about .coop__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .coop__steps li {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 11px 18px;
  border: 1px solid var(--about-rule-light);
  border-radius: 999px;
  font-size: 15px;
  color: rgba(243, 235, 221, 0.86);
}

.page-about .coop__steps span {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--brass-300);
}

/* ---------- 年度档案册 ---------- */
.page-about .annual {
  display: grid;
  gap: 28px;
}

.page-about .annual__text p {
  margin: 0 0 16px;
  max-width: 60ch;
  font-size: 16px;
  color: var(--slate-600);
}

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

.page-about .annual__facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  align-content: start;
  border-top: 1px solid var(--about-rule);
}

.page-about .annual__facts li {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--about-rule);
}

.page-about .annual__facts span {
  min-width: 92px;
  font-size: 18px;
  letter-spacing: 0.04em;
  color: var(--brass-700);
}

.page-about .annual__facts p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--slate-600);
}

/* ---------- 结尾联络条 ---------- */
.page-about .about-contact {
  padding: 48px 20px 64px;
}

.page-about .about-contact__inner {
  max-width: var(--shell-max);
  margin: 0 auto;
  display: grid;
  gap: 24px;
  padding: 28px 22px;
  border: 1px solid var(--about-rule);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(140deg, rgba(185, 133, 74, 0.16), rgba(220, 233, 227, 0.55));
}

.page-about .about-contact h2 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.03em;
  line-height: 1.4;
  font-size: clamp(1.28rem, 3.8vw, 1.72rem);
}

.page-about .about-contact p {
  margin: 0;
  max-width: 52ch;
  font-size: 15px;
  color: var(--slate-600);
}

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

/* ---------- 桌面端 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero {
    padding: 32px 40px 60px;
  }

  .page-about .about-hero__stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 26px;
  }

  .page-about .about-section {
    padding: 72px 40px;
  }

  .page-about .about-section--deep {
    margin: 0 24px;
    padding: 72px 40px;
  }

  .page-about .chapter-index {
    padding: 0 40px;
  }

  .page-about .about-contact {
    padding: 56px 40px 76px;
  }

  .page-about .about-contact__inner {
    padding: 36px 40px;
  }
}

@media (min-width: 900px) {
  .page-about .about-head {
    grid-template-columns: 64px minmax(0, 1fr);
    grid-template-areas:
      "idx title"
      "idx lede";
    column-gap: 24px;
    row-gap: 12px;
    align-items: start;
  }

  .page-about .about-head__idx {
    grid-area: idx;
    padding-top: 10px;
  }

  .page-about .about-head__title {
    grid-area: title;
  }

  .page-about .about-head__lede {
    grid-area: lede;
  }

  .page-about .about-lineage {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-figure--lineage {
    position: sticky;
    top: calc(var(--bar-h) + 24px);
  }

  .page-about .hall {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 32px;
  }

  .page-about .hall__num {
    padding-top: 6px;
  }

  .page-about .network {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.85fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .about-figure--network {
    margin-top: 0;
  }

  .page-about .coop {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 48px;
  }

  .page-about .annual {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-contact__inner {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
    align-items: center;
  }

  .page-about .about-contact__links {
    justify-content: flex-end;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .chapter-index__list a,
  .page-about .team-fold__trigger,
  .page-about .team-fold__trigger::after {
    transition: none;
  }
}