.page-about {
  --about-rail-w: 180px;
  --about-fade: rgba(47, 125, 92, .14);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 20px 0 0;
  background:
    linear-gradient(148deg, var(--c-green-pale) 0%, var(--c-paper) 44%, var(--c-paper) 100%);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -18%;
  width: 68%;
  height: 170%;
  background: linear-gradient(158deg, var(--about-fade), rgba(14, 31, 51, 0) 66%);
  transform: rotate(8deg);
  transform-origin: top right;
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  display: grid;
  gap: 34px;
  padding-bottom: 42px;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(32px, 7vw, 62px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--c-ink);
  margin: 14px 0 18px;
  max-width: 15em;
}

.page-about .about-hero .lede {
  max-width: 40em;
  color: var(--c-muted);
  font-size: 17px;
  line-height: 1.8;
  margin: 0;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .hero-stats {
  list-style: none;
  margin: 0;
  padding: 20px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 14px;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-card);
  background: rgba(251, 252, 249, .86);
  box-shadow: var(--shadow-soft);
}

.page-about .hero-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.page-about .hero-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 5vw, 34px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--c-green-deep);
}

.page-about .hero-stat--accent .hero-stat__num {
  color: var(--c-orange);
}

.page-about .hero-stat__label {
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.5;
  color: var(--c-muted);
}

.page-about .about-slant {
  position: relative;
  height: 3px;
  background: linear-gradient(90deg, var(--c-green) 0%, var(--c-cyan) 54%, var(--c-orange) 100%);
  transform: rotate(-1.2deg) scaleX(1.06);
  transform-origin: left center;
}

/* ---------- 轴线主体 ---------- */
.page-about .about-axis {
  background: var(--c-paper);
  padding-top: 32px;
}

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

.page-about .about-axis__rail {
  min-width: 0;
}

.page-about .axis-list {
  list-style: none;
  display: flex;
  gap: 8px;
  margin: 12px 0 0;
  padding: 0 0 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .axis-item {
  display: flex;
  align-items: center;
  gap: 7px;
  flex: 0 0 auto;
  padding: 7px 13px;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-pill);
  background: var(--c-paper);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .04em;
  color: var(--c-muted);
  white-space: nowrap;
}

.page-about .axis-num {
  color: var(--c-green);
  font-weight: 700;
}

.page-about .axis-item.is-active {
  border-color: var(--c-green);
  background: var(--c-green-pale);
  color: var(--c-green-deep);
}

.page-about .about-axis__stream {
  min-width: 0;
}

/* ---------- 阶段内容块 ---------- */
.page-about .axis-block {
  padding: 34px 0;
  border-top: 1px solid var(--c-line);
  min-width: 0;
}

.page-about .axis-block:first-of-type {
  border-top: 0;
  padding-top: 6px;
}

.page-about .axis-block--last {
  padding-bottom: 8px;
}

.page-about .axis-block--sand {
  border-top-color: transparent;
  border-radius: var(--radius-card);
  background: var(--c-sand);
  padding: 26px 20px;
}

.page-about .block-kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--c-green);
  margin: 0 0 10px;
}

.page-about .block-title {
  font-family: var(--font-display);
  font-size: clamp(24px, 4.4vw, 38px);
  font-weight: 900;
  line-height: 1.24;
  letter-spacing: -.015em;
  color: var(--c-ink);
  margin: 0 0 18px;
  max-width: 18em;
}

.page-about .block-body p {
  font-size: 17px;
  line-height: 1.82;
  color: var(--c-muted);
  margin: 0 0 14px;
  max-width: 42em;
}

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

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

.page-about .media-frame {
  margin: 0;
}

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

/* ---------- 图文错位 ---------- */
.page-about .block-split {
  display: grid;
  gap: 26px;
  min-width: 0;
}

.page-about .block-split__text {
  min-width: 0;
}

.page-about .block-split__text p {
  font-size: 17px;
  line-height: 1.82;
  color: var(--c-muted);
  margin: 0 0 14px;
}

.page-about .block-split__media {
  margin: 0;
}

/* ---------- 双城地点 ---------- */
.page-about .place-grid {
  display: grid;
  margin-top: 22px;
  border-top: 1px solid var(--c-line);
}

.page-about .place {
  padding: 18px 0;
  border-bottom: 1px solid var(--c-line);
}

.page-about .place__tag {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .14em;
  color: var(--c-cyan);
  margin: 0 0 6px;
}

.page-about .place__title {
  font-family: var(--font-heading);
  font-size: 17px;
  font-weight: 600;
  color: var(--c-ink);
  margin: 0 0 8px;
}

.page-about .place p:last-child {
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-muted);
  margin: 0;
}

/* ---------- 小组清单 ---------- */
.page-about .crew-list {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--c-line);
}

.page-about .crew {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  padding: 16px 0;
  border-bottom: 1px solid var(--c-line);
}

.page-about .crew__num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--c-orange);
  padding-top: 3px;
}

.page-about .crew__title {
  font-family: var(--font-heading);
  font-size: 17px;
  font-weight: 600;
  color: var(--c-ink);
  margin: 0 0 6px;
}

.page-about .crew__body p {
  font-size: 15px;
  line-height: 1.78;
  color: var(--c-muted);
  margin: 0;
}

/* ---------- 编年卡片 ---------- */
.page-about .chron-grid {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .chron-card {
  border: 1px solid var(--c-line);
  border-radius: var(--radius-card);
  background: var(--c-paper);
  padding: 18px 16px;
  transition: border-color .25s ease, box-shadow .25s ease, transform .25s ease;
}

.page-about .chron-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--c-green-deep);
  margin-bottom: 10px;
}

.page-about .chron-title {
  font-family: var(--font-heading);
  font-size: 16px;
  font-weight: 600;
  color: var(--c-ink);
  margin: 0 0 8px;
}

.page-about .chron-text {
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-muted);
  margin: 0;
}

.page-about .chron-note {
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--c-green-deep);
  margin: 0;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height .35s ease, opacity .3s ease, margin-top .3s ease;
}

@media (hover: hover) {
  .page-about .chron-card:hover {
    border-color: var(--c-orange);
    box-shadow: var(--shadow-card);
  }

  .page-about .chron-card:hover .chron-note {
    max-height: 8em;
    opacity: 1;
    margin-top: 12px;
  }
}

@media (hover: none) {
  .page-about .chron-note {
    max-height: none;
    opacity: 1;
    margin-top: 12px;
  }
}

/* ---------- 合作方向 ---------- */
.page-about .coop-list {
  margin-top: 22px;
}

.page-about .coop {
  border: 1px solid var(--c-line);
  border-radius: var(--radius-card);
  background: var(--c-paper);
  margin-bottom: 12px;
  transition: border-color .25s ease, box-shadow .25s ease;
}

.page-about .coop:hover {
  border-color: var(--c-orange);
}

.page-about .coop[open] {
  border-color: var(--c-green);
  box-shadow: var(--shadow-soft);
}

.page-about .coop__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 17px 18px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-heading);
  font-size: 16.5px;
  font-weight: 600;
  color: var(--c-ink);
}

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

.page-about .coop__flag {
  position: relative;
  flex: 0 0 14px;
  width: 14px;
  height: 14px;
}

.page-about .coop__flag::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 14px;
  height: 2px;
  border-radius: 1px;
  background: var(--c-green);
}

.page-about .coop__flag::after {
  content: "";
  position: absolute;
  left: 6px;
  top: 0;
  width: 2px;
  height: 14px;
  border-radius: 1px;
  background: var(--c-green);
  transition: transform .25s ease;
}

.page-about .coop[open] .coop__flag::after {
  transform: scaleY(0);
}

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

.page-about .coop__body p {
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--c-muted);
  margin: 0 0 12px;
}

.page-about .coop__contact {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-green-deep);
  border-left: 2px solid var(--c-orange);
  padding-left: 12px;
  margin-bottom: 0 !important;
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 700px) {
  .page-about .hero-stats {
    padding: 24px;
    gap: 22px 20px;
  }

  .page-about .place-grid {
    grid-template-columns: 1fr 1fr;
    column-gap: 36px;
    border-bottom: 1px solid var(--c-line);
  }

  .page-about .place {
    border-bottom: 0;
  }

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

  .page-about .axis-block--sand {
    padding: 32px 28px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding-top: 26px;
  }

  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.3fr) minmax(280px, .7fr);
    align-items: end;
    gap: 60px;
    padding-bottom: 64px;
  }

  .page-about .about-axis {
    padding-top: 48px;
  }

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

  .page-about .about-axis__rail {
    position: sticky;
    top: 104px;
    padding-top: 6px;
  }

  .page-about .axis-list {
    flex-direction: column;
    gap: 0;
    padding: 0;
    overflow: visible;
    border-left: 1px solid var(--c-line);
    margin-top: 14px;
  }

  .page-about .axis-item {
    position: relative;
    border: 0;
    border-radius: 0;
    background: none;
    padding: 11px 0 11px 20px;
    white-space: normal;
    font-size: 12px;
    letter-spacing: .05em;
  }

  .page-about .axis-item::before {
    content: "";
    position: absolute;
    left: -5px;
    top: 50%;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--c-paper);
    border: 1px solid var(--c-line);
    transform: translateY(-50%);
    transition: background .25s ease, border-color .25s ease, box-shadow .25s ease;
  }

  .page-about .axis-item.is-active {
    background: none;
    color: var(--c-green-deep);
    font-weight: 700;
  }

  .page-about .axis-item.is-active::before {
    background: var(--c-green);
    border-color: var(--c-green);
    box-shadow: 0 0 0 4px rgba(47, 125, 92, .16);
  }

  .page-about .axis-block {
    padding: 44px 0;
  }

  .page-about .axis-block:first-of-type {
    padding-top: 0;
  }

  .page-about .block-split {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
    gap: 44px;
    align-items: start;
    margin-top: 6px;
  }

  .page-about .axis-block--flip .block-split {
    grid-template-columns: minmax(0, .92fr) minmax(0, 1.08fr);
  }

  .page-about .axis-block--flip .block-split__media {
    order: -1;
  }

  .page-about .block-figure {
    margin-top: 30px;
  }

  .page-about .chron-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .axis-block--sand {
    padding: 36px 34px;
  }

  .page-about .coop__head {
    padding: 19px 22px;
  }

  .page-about .coop__body {
    padding: 0 22px 20px;
  }
}