.page-about {
  --about-node-w: clamp(196px, 62vw, 232px);
  overflow-x: hidden;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: 14px;
}

/* ---------- 使命陈述 ---------- */
.page-about .about-mission {
  padding-top: 8px;
}

.page-about .about-mission-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}

.page-about .about-mission-title {
  margin: 12px 0 16px;
  font-size: clamp(30px, 8.4vw, 56px);
  line-height: 1.05;
  letter-spacing: -.02em;
}

.page-about .about-mission-copy p {
  margin: 0 0 16px;
  max-width: 68ch;
}

.page-about .about-mission-copy .about-lede {
  margin: 0 0 18px;
}

.page-about .about-facts {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  border: 2px solid var(--edge);
  background: var(--edge-soft);
}

.page-about .about-facts li {
  background: var(--moss);
  padding: 14px 14px 16px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--stone);
}

.page-about .about-facts .num {
  display: block;
  font-family: var(--font-numeric);
  font-size: 24px;
  line-height: 1.1;
  color: var(--lime);
  margin-bottom: 4px;
}

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

.page-about .about-mission-figure .media-frame {
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border: 2px solid var(--edge);
  box-shadow: var(--shadow-hard);
}

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

.page-about .about-mission-figure figcaption {
  margin-top: 10px;
}

/* ---------- 三条内容线 ---------- */
.page-about .about-lines {
  background: linear-gradient(158deg, rgba(14, 43, 37, .92) 0%, rgba(14, 43, 37, .55) 46%, rgba(10, 26, 43, .2) 100%);
}

.page-about .about-sec-head {
  max-width: 68ch;
}

.page-about .about-h2 {
  margin: 10px 0 12px;
  font-size: clamp(24px, 5.6vw, 40px);
  line-height: 1.12;
  letter-spacing: -.015em;
}

.page-about .about-sec-intro {
  margin: 0;
  color: var(--stone);
  max-width: 68ch;
}

.page-about .about-branches {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
  margin-top: 34px;
  padding-bottom: 6px;
}

.page-about .about-line-card {
  position: relative;
  padding: 22px 20px 20px;
  background: var(--moss);
  border: 2px solid var(--edge);
  box-shadow: var(--shadow-hard);
  transition: transform .28s var(--ease-out), border-color .28s var(--ease-out);
}

.page-about .about-line-card:hover,
.page-about .about-line-card:focus-within {
  transform: translateY(-4px);
  border-color: var(--lime);
}

.page-about .about-line-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.page-about .about-line-count {
  font-family: var(--font-numeric);
  font-size: 15px;
  letter-spacing: .02em;
  color: var(--gold);
  white-space: nowrap;
}

.page-about .about-line-desc {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--stone);
}

.page-about .about-line-more {
  display: grid;
  grid-template-rows: 1fr;
  transition: grid-template-rows .34s var(--ease-out), opacity .34s var(--ease-out);
}

.page-about .about-line-more-inner {
  overflow: hidden;
  min-height: 0;
}

.page-about .about-line-more-label {
  margin: 0 0 10px;
  padding-top: 14px;
  border-top: 1px dashed var(--edge-soft);
}

.page-about .about-line-outputs {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .about-line-outputs li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--bone);
}

.page-about .about-line-outputs li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--lime);
}

.page-about .about-lines-links {
  margin: 30px 0 0;
  font-size: 14px;
  color: var(--stone);
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.page-about .about-lines-links a {
  color: var(--lime);
  text-decoration: none;
  border-bottom: 1px solid rgba(201, 242, 77, .45);
  padding-bottom: 2px;
}

.page-about .about-lines-links a:hover {
  border-bottom-color: var(--lime);
}

/* ---------- 运营历程 ---------- */
.page-about .about-history-head {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
}

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

.page-about .about-history-figure .media-frame {
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border: 2px solid var(--edge);
  box-shadow: var(--shadow-hard);
}

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

.page-about .about-history-figure figcaption {
  margin-top: 10px;
}

.page-about .about-timeline {
  display: flex;
  margin: 32px 0 0;
  padding: 4px 0 20px;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: var(--stone) transparent;
}

.page-about .about-timeline::-webkit-scrollbar {
  height: 6px;
}

.page-about .about-timeline::-webkit-scrollbar-thumb {
  background: var(--stone);
}

.page-about .about-tl-node {
  flex: 0 0 auto;
  width: var(--about-node-w);
  padding-right: 18px;
  scroll-snap-align: start;
}

.page-about .about-tl-rail {
  position: relative;
  height: 104px;
}

.page-about .about-tl-year {
  position: absolute;
  left: 0;
  top: 0;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-numeric);
  font-size: 14px;
  line-height: 1.15;
  letter-spacing: .08em;
  color: var(--gold);
}

.page-about .about-tl-rail::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 82px;
  height: 2px;
  background: var(--edge-soft);
}

.page-about .about-tl-node:last-child .about-tl-rail::after {
  background: linear-gradient(90deg, var(--edge-soft) 0%, rgba(138, 150, 143, 0) 78%);
}

.page-about .about-tl-dot {
  position: absolute;
  left: 6px;
  top: 75px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--gold);
  border: 2px solid var(--night);
  box-sizing: content-box;
  z-index: 1;
}

.page-about .about-tl-body {
  padding-top: 12px;
}

.page-about .about-tl-title {
  margin: 0 0 8px;
  font-size: 17px;
  line-height: 1.3;
  letter-spacing: -.01em;
  color: var(--bone);
}

.page-about .about-tl-body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--stone);
}

/* ---------- 一起做内容 ---------- */
.page-about .about-collab-shell {
  position: relative;
  overflow: hidden;
  border: 2px solid var(--edge);
  box-shadow: var(--shadow-hard);
  background: var(--pine);
}

.page-about .about-collab-media {
  position: absolute;
  inset: 0;
}

.page-about .about-collab-media img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  opacity: .34;
}

.page-about .about-collab-shell::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(115deg, rgba(10, 26, 43, .96) 6%, rgba(14, 43, 37, .84) 54%, rgba(28, 68, 56, .42) 100%);
}

.page-about .about-collab-copy {
  position: relative;
  z-index: 1;
  padding: 30px 22px;
}

.page-about .about-collab-copy p {
  max-width: 66ch;
  color: rgba(241, 238, 227, .88);
}

.page-about .about-collab-stats {
  list-style: none;
  margin: 24px 0 22px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-collab-stats li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding-left: 12px;
  border-left: 3px solid var(--lime);
  font-size: 15px;
  color: var(--bone);
}

.page-about .about-collab-stats .num {
  font-family: var(--font-numeric);
  font-size: 26px;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-collab-copy .btn {
  margin-top: 6px;
}

/* ---------- 合作与投稿 ---------- */
.page-about .about-join-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

.page-about .about-join-list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-join-item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 16px;
  background: var(--moss);
  border: 2px solid var(--edge);
  box-shadow: var(--shadow-soft);
  transition: transform .28s var(--ease-out);
}

.page-about .about-join-item:hover {
  transform: translateY(-4px);
}

.page-about .about-join-index {
  font-family: var(--font-numeric);
  font-size: 22px;
  line-height: 1;
  color: var(--gold);
}

.page-about .about-join-item h3 {
  margin: 0 0 8px;
  font-size: 17px;
  line-height: 1.3;
  color: var(--bone);
}

.page-about .about-join-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--stone);
}

.page-about .about-join-aside {
  padding: 24px 20px;
}

.page-about .about-join-aside .annotation {
  display: block;
  margin: 0 0 14px;
}

.page-about .about-join-email {
  margin: 0 0 12px;
  font-family: var(--font-numeric);
  font-size: 15px;
  line-height: 1.5;
  color: var(--lime);
  word-break: break-all;
}

.page-about .about-join-note {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--stone);
}

.page-about .about-join-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

/* ---------- 中等屏幕 ---------- */
@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-mission-grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-history-head {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    align-items: end;
    gap: 36px;
  }

  .page-about .about-collab-copy {
    padding: 40px 34px;
  }

  .page-about .about-collab-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-collab-stats li {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }
}

/* ---------- 宽屏：错位卡片与展开 ---------- */
@media (min-width: 880px) {
  .page-about .about-branches {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
    gap: 26px;
    padding-bottom: 50px;
  }

  .page-about .about-line-card:nth-child(2) {
    margin-top: 22px;
  }

  .page-about .about-line-card:nth-child(3) {
    margin-top: 44px;
  }

  .page-about .about-line-more {
    grid-template-rows: 0fr;
    opacity: 0;
  }

  .page-about .about-line-card:hover .about-line-more,
  .page-about .about-line-card:focus-within .about-line-more {
    grid-template-rows: 1fr;
    opacity: 1;
  }

  .page-about .about-join-grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    align-items: start;
    gap: 34px;
  }

  .page-about .about-join-aside {
    position: sticky;
    top: 28px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-mission-grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-collab-copy {
    padding: 48px 44px;
  }
}