.page-about {
  --about-rail-w: 220px;
  --about-gap: 64px;
  --about-pad: 24px;
  display: block;
}

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

/* ---------- 首屏框景 ---------- */
.page-about .about-intro {
  position: relative;
  padding: 40px var(--about-pad) 44px;
  border: var(--line);
  background:
    radial-gradient(120% 100% at 6% 0%, rgba(47, 107, 255, 0.16), transparent 62%),
    linear-gradient(180deg, var(--rail) 0%, var(--bg) 100%);
  margin-bottom: 56px;
  overflow: hidden;
}

.page-about .about-intro::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 76px;
  height: 3px;
  background: var(--accent);
}

.page-about .about-intro__inner {
  max-width: 880px;
}

.page-about .about-intro__title {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(2.3rem, 6vw, 4.4rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 14px 0 22px;
}

.page-about .about-intro__lede {
  color: var(--muted);
  font-size: 16px;
  line-height: 1.8;
  margin: 0;
  max-width: 760px;
}

.page-about .about-intro__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 34px 0 0;
  padding: 0;
  background: var(--grid);
  border: var(--line);
}

.page-about .about-stat {
  background: var(--panel);
  padding: 15px 16px 17px;
  min-width: 0;
}

.page-about .about-stat__label {
  margin: 0 0 7px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .about-stat__value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  color: var(--ink);
  position: relative;
  top: -1px;
}

/* ---------- 两栏骨架 ---------- */
.page-about .page-shell {
  display: block;
  padding-bottom: 88px;
}

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

/* ---------- 年份刻度侧轨 ---------- */
.page-about .about-rail {
  margin: 0 0 44px;
}

.page-about .about-rail__title {
  display: none;
}

.page-about .about-rail__nav {
  display: flex;
  gap: 0;
  overflow-x: auto;
  border-top: var(--line);
  border-bottom: var(--line);
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__link {
  position: relative;
  flex: 0 0 auto;
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 13px 22px 13px 0;
  white-space: nowrap;
  text-decoration: none;
  color: var(--muted);
  font-size: 14px;
  border-bottom: 2px solid transparent;
}

.page-about .about-rail__link.is-current {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

.page-about .about-rail__year {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent);
}

.page-about .about-rail__label {
  color: inherit;
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  margin-bottom: 72px;
  padding-top: 4px;
}

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

.page-about .chapter__index {
  font-family: var(--font-mono);
  color: var(--accent);
}

.page-about .chapter__title {
  overflow-wrap: break-word;
}

.page-about .chapter__lede {
  max-width: 640px;
}

.page-about .about-chapter .chapter__body {
  margin-top: 30px;
}

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

.page-about .about-figure--wide {
  margin-bottom: 40px;
}

.page-about .about-figure .media-frame {
  border: var(--line);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-figure .media-frame--wide {
  aspect-ratio: 7 / 4;
}

.page-about .about-figure .media-frame--square {
  aspect-ratio: 10 / 7;
}

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

.page-about .about-figure .figure__cap {
  margin-top: 10px;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.6;
}

/* ---------- 网格 ---------- */
.page-about .about-grid {
  display: grid;
  gap: 30px;
  align-items: start;
}

.page-about .about-grid > * {
  min-width: 0;
}

.page-about .about-panel {
  border: var(--line);
  background: var(--panel);
}

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

.page-about .about-list li {
  position: relative;
  padding: 11px 0 11px 20px;
  border-bottom: var(--line);
  color: var(--muted);
  font-size: 15px;
  line-height: 1.7;
}

.page-about .about-list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 20px;
  width: 9px;
  height: 1px;
  background: var(--accent);
}

/* ---------- 流程步骤 ---------- */
.page-about .steps {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: none;
}

.page-about .steps__item {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  column-gap: 16px;
  border-top: var(--line);
  padding: 20px 0 22px;
}

.page-about .steps__item:last-child {
  border-bottom: var(--line);
}

.page-about .steps__num {
  grid-row: span 2;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
  padding-top: 4px;
}

.page-about .steps__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 18px;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .steps__text {
  margin: 7px 0 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 发展时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 12px;
  width: 1px;
  background: var(--grid);
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 34px 40px;
}

.page-about .timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 5px;
  width: 13px;
  height: 13px;
  box-sizing: border-box;
  border: 1px solid var(--grid);
  background: var(--bg);
}

.page-about .timeline__item::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 9px;
  width: 5px;
  height: 5px;
  background: var(--accent);
  opacity: 0.35;
  transition: opacity 0.25s ease;
}

.page-about .timeline__item:hover::after {
  opacity: 1;
}

.page-about .timeline__year {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--accent);
  margin-bottom: 8px;
}

.page-about .timeline__title {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 19px;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .timeline__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
  max-width: 620px;
}

/* ---------- 团队矩阵 ---------- */
.page-about .about-team {
  border-top: var(--line);
  border-bottom: var(--line);
}

.page-about .about-team .accordion__item {
  border-bottom: var(--line);
  background: linear-gradient(90deg, rgba(28, 38, 34, 0) 0%, rgba(28, 38, 34, 0.55) 100%);
  transition: background 0.2s ease;
}

.page-about .about-team .accordion__item:last-child {
  border-bottom: 0;
}

.page-about .about-team .accordion__item:hover {
  background: linear-gradient(90deg, rgba(182, 255, 60, 0.05) 0%, rgba(28, 38, 34, 0.7) 100%);
}

.page-about .about-team .accordion__trigger {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr) 20px;
  align-items: center;
  column-gap: 14px;
  width: 100%;
  padding: 18px 12px 18px 4px;
  background: none;
  border: 0;
  text-align: left;
  cursor: pointer;
  color: var(--ink);
  font-family: inherit;
  font-size: inherit;
  border-left: 2px solid transparent;
  transition: border-color 0.2s ease;
}

.page-about .about-team .accordion__trigger:hover,
.page-about .about-team .accordion__trigger:focus-visible {
  border-left-color: var(--accent);
}

.page-about .about-team .accordion__index {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
}

.page-about .about-team .accordion__label {
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 17px;
  line-height: 1.45;
  min-width: 0;
  overflow-wrap: break-word;
}

.page-about .about-team .accordion__panel p {
  margin: 0;
  padding: 0 16px 20px 58px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 720px;
}

/* ---------- 栏目目录 ---------- */
.page-about .about-catalog {
  list-style: none;
  margin: 0 0 40px;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--grid);
  border: var(--line);
}

.page-about .about-catalog__item {
  background: var(--bg);
  padding: 20px 18px 22px;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  column-gap: 14px;
  min-width: 0;
}

.page-about .about-catalog__index {
  grid-row: span 2;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent);
  padding-top: 5px;
}

.page-about .about-catalog__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 18px;
  line-height: 1.4;
}

.page-about .about-catalog__title a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--grid);
  padding-bottom: 2px;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-catalog__title a:hover,
.page-about .about-catalog__title a:focus-visible {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.page-about .about-catalog__text {
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 联系 ---------- */
.page-about .about-contact {
  border: var(--line);
  border-left: 3px solid var(--accent);
  background: linear-gradient(180deg, var(--rail) 0%, var(--bg) 100%);
  padding: 26px var(--about-pad) 28px;
}

.page-about .about-contact__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.4rem, 3vw, 1.9rem);
  letter-spacing: -0.01em;
  color: var(--ink);
}

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

.page-about .about-contact__cell {
  min-width: 0;
  padding-bottom: 14px;
  border-bottom: var(--line);
}

.page-about .about-contact__cell:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-contact__label {
  display: block;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-bottom: 6px;
}

.page-about .about-contact__value {
  display: block;
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  overflow-wrap: break-word;
}

.page-about .about-contact__value--mono {
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

.page-about .about-contact__note {
  margin: 22px 0 0;
  padding-top: 18px;
  border-top: var(--line);
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
  max-width: 680px;
}

.page-about .about-contact__note a {
  color: var(--data);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about {
    --about-pad: 36px;
  }

  .page-about .about-intro {
    padding: 52px var(--about-pad) 56px;
  }

  .page-about .about-intro__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-contact__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px 32px;
  }
}

@media (min-width: 900px) {
  .page-about .about-grid--7-5 {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 44px;
  }

  .page-about .about-grid--5-7 {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 44px;
  }

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

  .page-about .about-chapter {
    margin-bottom: 88px;
  }
}

@media (min-width: 1024px) {
  .page-about {
    --about-gap: 60px;
  }

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

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-offset) + 18px);
    margin: 0;
  }

  .page-about .about-rail__title {
    display: block;
    margin: 0 0 20px;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.14em;
    color: var(--muted);
  }

  .page-about .about-rail__nav {
    display: block;
    position: relative;
    overflow: visible;
    border-top: 0;
    border-bottom: 0;
    padding-left: 22px;
  }

  .page-about .about-rail__nav::before {
    content: "";
    position: absolute;
    left: 4px;
    top: 6px;
    bottom: 26px;
    width: 1px;
    background: var(--grid);
  }

  .page-about .about-rail__link {
    display: block;
    padding: 0 0 26px;
    white-space: normal;
    border-bottom: 0;
  }

  .page-about .about-rail__link::before {
    content: "";
    position: absolute;
    left: -22px;
    top: 4px;
    width: 9px;
    height: 9px;
    box-sizing: border-box;
    border: 1px solid var(--grid);
    background: var(--bg);
    transition: background 0.2s ease, border-color 0.2s ease;
  }

  .page-about .about-rail__link.is-current::before {
    background: var(--accent);
    border-color: var(--accent);
  }

  .page-about .about-rail__year {
    display: block;
    margin-bottom: 3px;
  }

  .page-about .about-rail__label {
    display: block;
    font-size: 14px;
    line-height: 1.45;
  }

  .page-about .about-rail__link.is-current .about-rail__label {
    color: var(--ink);
  }

  .page-about .about-chapter:nth-of-type(even) .chapter__head,
  .page-about .about-chapter:nth-of-type(even) .chapter__body {
    margin-left: 52px;
  }

  .page-about .about-intro {
    padding: 68px 56px 72px;
    margin-bottom: 72px;
  }

  .page-about .about-figure--wide {
    margin-bottom: 56px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-intro__inner {
    max-width: 940px;
  }

  .page-about .about-chapter:nth-of-type(even) .chapter__head,
  .page-about .about-chapter:nth-of-type(even) .chapter__body {
    margin-left: 76px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .timeline__item::after,
  .page-about .about-team .accordion__trigger,
  .page-about .about-catalog__title a,
  .page-about .about-rail__link::before {
    transition: none;
  }
}