.page-about {
  --about-gap: clamp(44px, 7vw, 88px);
  overflow-x: clip;
}

.page-about .breadcrumb {
  padding: 18px 0 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(20px, 4vw, 44px) 0 clamp(32px, 5vw, 56px);
  border-bottom: var(--bd);
}

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

.page-about .about-hero__kicker {
  margin: 0 0 14px;
  font-size: var(--t-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--grass);
}

.page-about h1 {
  margin: 0 0 18px;
  font-size: clamp(30px, 5.4vw, 52px);
  line-height: 1.14;
  font-weight: 900;
  letter-spacing: 0.01em;
  color: var(--night);
}

.page-about .about-hero__intro {
  margin: 0 0 26px;
  max-width: 64ch;
  font-size: var(--t-lg);
  line-height: 1.78;
  color: var(--night);
}

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

.page-about .about-hero__facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px;
  border: var(--bd);
  background: var(--metal);
  box-shadow: var(--shadow-1);
}

.page-about .about-fact:first-child {
  background: var(--grass);
}

.page-about .about-fact__k {
  font-size: var(--t-xs);
  letter-spacing: 0.12em;
  color: var(--grass);
}

.page-about .about-fact:first-child .about-fact__k {
  color: var(--orange-soft);
}

.page-about .about-fact__v {
  font-size: var(--t-xl);
  font-weight: 700;
  line-height: 1.1;
  color: var(--night);
}

.page-about .about-fact:first-child .about-fact__v {
  color: var(--metal);
}

/* ---------- 阶段轴 ---------- */
.page-about .about-stages {
  padding: var(--about-gap) 0 0;
}

.page-about .about-stages__media {
  margin: 0 0 26px;
}

.page-about .about-axis__track {
  list-style: none;
  margin: 0;
  padding: 6px 6px 22px;
  display: flex;
  gap: 14px;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-axis__node {
  flex: 0 0 min(258px, 76vw);
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 16px;
  border: var(--bd);
  background: var(--metal);
  box-shadow: var(--shadow-1);
  transition: border-color 0.16s ease, box-shadow 0.16s ease, transform 0.16s ease;
}

.page-about .about-axis__year {
  align-self: flex-start;
  font-size: var(--t-xl);
  font-weight: 700;
  color: var(--grass);
}

.page-about .about-axis__node--current .about-axis__year {
  padding: 2px 10px;
  background: var(--orange);
  color: var(--night);
}

.page-about .about-axis__title {
  margin: 0;
  font-size: var(--t-lg);
  font-weight: 900;
  color: var(--night);
}

.page-about .about-axis__text {
  margin: 0;
  font-size: var(--t-sm);
  line-height: 1.7;
  color: var(--night);
}

.page-about .about-axis__more {
  margin: 4px 0 0;
  padding-top: 9px;
  font-size: var(--t-xs);
  color: var(--grass-deep);
  border-top: 1px dashed var(--fog);
  transition: opacity 0.18s ease, transform 0.18s ease, max-height 0.18s ease;
}

/* ---------- 阶段详情 ---------- */
.page-about .about-phases {
  padding: var(--about-gap) 0 0;
}

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

.page-about .about-dossier__index-head {
  margin: 0 0 12px;
  font-size: var(--t-xs);
  letter-spacing: 0.16em;
  color: var(--grass);
}

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

.page-about .about-dossier__link {
  display: inline-block;
  padding: 6px 10px;
  border: 2px solid var(--night);
  background: var(--metal);
  box-shadow: 3px 3px 0 var(--night);
  font-family: var(--font-mono);
  font-size: var(--t-xs);
  color: var(--night);
  text-decoration: none;
  transition: background-color 0.16s ease, box-shadow 0.16s ease, color 0.16s ease;
}

.page-about .about-dossier__link:hover {
  background: var(--orange);
  box-shadow: 3px 3px 0 var(--grass-deep);
}

.page-about .about-dossier__item {
  margin: 0 0 24px;
  padding: 0 0 22px 18px;
  border-left: 4px solid var(--grass);
  scroll-margin-top: 96px;
}

.page-about .about-dossier__item:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-left-color: var(--orange);
}

.page-about .about-dossier__item h3 {
  margin: 0 0 10px;
  font-size: var(--t-xl);
  font-weight: 900;
  color: var(--night);
}

.page-about .about-dossier__item p {
  margin: 0;
  max-width: 68ch;
  font-size: var(--t-md);
  line-height: 1.8;
  color: var(--night);
}

/* ---------- 地域 ---------- */
.page-about .about-region {
  padding: var(--about-gap) 0 0;
}

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

.page-about .about-region h2 {
  margin: 0 0 16px;
  font-size: clamp(26px, 3.8vw, 34px);
  font-weight: 900;
  line-height: 1.25;
  color: var(--night);
}

.page-about .about-region__text p {
  margin: 0 0 14px;
  max-width: 62ch;
  font-size: var(--t-md);
  line-height: 1.8;
  color: var(--night);
}

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

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

/* ---------- 档案库 ---------- */
.page-about .about-archive {
  padding: var(--about-gap) 0 0;
}

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

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

.page-about .about-archive__lead {
  margin: 0 0 22px;
  max-width: 64ch;
  font-size: var(--t-md);
  line-height: 1.8;
  color: var(--night);
}

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

.page-about .about-line .disclosure__trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

.page-about .about-line .disclosure__title {
  font-weight: 900;
  font-size: var(--t-lg);
  color: var(--night);
}

.page-about .about-line .disclosure__mark {
  font-size: var(--t-xl);
  line-height: 1;
  color: var(--orange);
  transition: transform 0.16s ease;
}

.page-about .about-line[data-open] .disclosure__mark {
  transform: rotate(90deg);
}

.page-about .about-line .disclosure__body p {
  margin: 0;
  max-width: 64ch;
  font-size: var(--t-md);
  line-height: 1.8;
  color: var(--night);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  padding: var(--about-gap) 0 0;
}

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

.page-about .about-team__lead {
  margin: 0;
  max-width: 66ch;
  font-size: var(--t-md);
  line-height: 1.8;
  color: var(--night);
}

.page-about .about-flow {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-flow__step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 16px;
  align-items: baseline;
  padding: 16px 18px;
  border: var(--bd);
  background: var(--metal);
  box-shadow: var(--shadow-1);
  transition: border-color 0.16s ease, box-shadow 0.16s ease, transform 0.16s ease;
}

.page-about .about-flow__step:hover {
  border-color: var(--orange);
  box-shadow: var(--shadow-2);
  transform: translate(-2px, -2px);
}

.page-about .about-flow__no {
  grid-row: span 2;
  font-size: var(--t-2xl);
  font-weight: 700;
  color: var(--orange);
}

.page-about .about-flow__step h3 {
  margin: 0;
  font-size: var(--t-lg);
  font-weight: 900;
  color: var(--night);
}

.page-about .about-flow__step p {
  margin: 0;
  font-size: var(--t-sm);
  line-height: 1.75;
  color: var(--night);
}

.page-about .about-team__side {
  display: grid;
  gap: 16px;
  align-content: start;
}

.page-about .about-side-panel .panel__body ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-side-panel .panel__body li {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: baseline;
  font-size: var(--t-sm);
  line-height: 1.65;
  color: var(--night);
}

.page-about .about-side-panel .num {
  color: var(--grass);
  font-weight: 700;
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  padding: var(--about-gap) 0 0;
}

.page-about .about-partners__grid {
  display: grid;
  gap: 14px;
}

.page-about .about-partner {
  padding: 20px 18px;
  border: var(--bd);
  background: var(--grass-deep);
  box-shadow: var(--shadow-1);
}

.page-about .about-partner__num {
  margin: 0 0 8px;
  font-size: var(--t-2xl);
  font-weight: 700;
  color: var(--orange);
}

.page-about .about-partner h3 {
  margin: 0 0 8px;
  font-size: var(--t-lg);
  font-weight: 900;
  color: var(--metal);
}

.page-about .about-partner p {
  margin: 0;
  font-size: var(--t-sm);
  line-height: 1.7;
  color: var(--metal);
}

/* ---------- 下一阶段 ---------- */
.page-about .about-next {
  margin-top: var(--about-gap);
  padding: clamp(24px, 4vw, 42px);
  border: var(--bd);
  background: var(--night);
  box-shadow: var(--shadow-2);
  display: grid;
  gap: 24px;
}

.page-about .about-next h2 {
  margin: 0 0 14px;
  font-size: clamp(24px, 3.6vw, 34px);
  font-weight: 900;
  line-height: 1.25;
  color: var(--metal);
}

.page-about .about-next .sec-head__label {
  color: var(--aqua);
}

.page-about .about-next__text p {
  margin: 0;
  max-width: 64ch;
  font-size: var(--t-md);
  line-height: 1.8;
  color: var(--metal);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

.page-about .about-next__plain {
  font-family: var(--font-mono);
  font-size: var(--t-sm);
  color: var(--aqua);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.page-about .about-next__plain:hover {
  color: var(--orange);
}

/* ---------- 图片兜底 ---------- */
.page-about .media-frame img {
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 桌面增强 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-hero__facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-partners__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 880px) {
  .page-about .about-region__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: 42px;
    align-items: center;
  }

  .page-about .about-archive__grid {
    grid-template-columns: 320px minmax(0, 1fr);
    gap: 42px;
    align-items: start;
  }

  .page-about .about-dossier {
    grid-template-columns: 196px minmax(0, 1fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .about-dossier__index {
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .page-about .about-dossier__index-list {
    flex-direction: column;
    flex-wrap: nowrap;
  }

  .page-about .about-dossier__link {
    width: 100%;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 38px;
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .page-about .about-partners__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-next {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    align-items: center;
  }

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

@media (hover: hover) and (min-width: 760px) {
  .page-about .about-axis__more {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transform: translateY(4px);
  }

  .page-about .about-axis__node:hover .about-axis__more,
  .page-about .about-axis__node:focus-within .about-axis__more {
    max-height: 90px;
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition: none !important;
  }
}