.page-about {
  background: var(--night);
  color: var(--white);
  overflow-x: clip;
}

.page-about .crumbs {
  padding-top: 22px;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  letter-spacing: -0.02em;
}

.page-about h1 {
  margin: 12px 0 0;
  font-size: clamp(30px, 5.6vw, 56px);
  line-height: 1.14;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.page-about .lede {
  max-width: 40ch;
}

.page-about .section-head h2 {
  font-size: clamp(24px, 3.6vw, 38px);
  line-height: 1.2;
  margin: 10px 0 12px;
}

.page-about .section-head .lede {
  max-width: 56ch;
}

/* ── Hero ─────────────────────────────── */
.page-about .about-hero {
  padding-top: 26px;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 26px;
  align-items: center;
}

.page-about .about-hero__copy .lede {
  margin-top: 16px;
}

.page-about .about-hero__copy .pill-row {
  margin-top: 22px;
}

.page-about .about-hero__board {
  width: min(100%, 320px);
  margin: 0 auto;
  aspect-ratio: 1;
}

.page-about .about-orbit {
  display: block;
  width: 100%;
  height: 100%;
}

.page-about .about-hero__media {
  margin-top: 34px;
  border-radius: var(--r-xl);
  border: 1px solid var(--line);
  background: var(--ink);
  overflow: hidden;
  box-shadow: var(--shadow-panel);
}

.page-about .about-hero__media img {
  display: block;
  width: 100%;
  height: clamp(170px, 30vw, 360px);
  object-fit: cover;
  max-width: 100%;
}

/* ── 起点数字条 ───────────────────────── */
.page-about .about-origin {
  padding: 46px 0 12px;
}

.page-about .about-origin__grid {
  display: grid;
  gap: 14px;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .origin-cell {
  background: var(--ink);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 20px 22px 22px;
}

.page-about .about-origin .num {
  display: block;
  font-size: clamp(36px, 7vw, 54px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--cyan);
  margin-bottom: 10px;
}

.page-about .about-origin .num em {
  font-style: normal;
  font-size: 0.42em;
  margin-left: 4px;
  color: var(--mint);
}

.page-about .origin-cell p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mint);
}

/* ── 时间线 ───────────────────────────── */
.page-about .about-timeline {
  padding: 52px 0 40px;
  background: linear-gradient(180deg, var(--night) 0%, var(--ink) 26%, var(--ink) 100%);
}

.page-about .timeline {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 26px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--glow) 58%, var(--line) 100%);
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 24px 32px;
  scroll-margin-top: calc(var(--header-h) + 28px);
}

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

.page-about .timeline__dot {
  position: absolute;
  left: 0;
  top: 4px;
  width: 16px;
  height: 16px;
  display: block;
  border-radius: 50%;
  border: 2px solid var(--cyan);
  background: var(--ink);
  z-index: 1;
  transition: transform 0.24s var(--ease), box-shadow 0.24s var(--ease);
}

.page-about .timeline__dot:hover {
  transform: scale(1.18);
}

.page-about .timeline__dot:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}

.page-about .timeline__item--now .timeline__dot {
  border-color: var(--orange);
  box-shadow: 0 0 0 5px rgba(255, 106, 43, 0.16);
}

.page-about .timeline__year {
  display: block;
  font-family: var(--font-num);
  font-size: 38px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--mint);
  margin-bottom: 12px;
}

.page-about .timeline__item--now .timeline__year {
  color: var(--orange);
}

.page-about .research-board {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 20px;
  display: grid;
  gap: 16px;
  transition: border-color 0.24s var(--ease), box-shadow 0.24s var(--ease);
}

.page-about .research-board:hover {
  border-color: rgba(53, 232, 208, 0.5);
  box-shadow: 0 0 0 1px rgba(53, 232, 208, 0.16), 0 18px 40px rgba(0, 0, 0, 0.4);
}

.page-about .timeline__item:target .research-board {
  border-color: var(--cyan);
  box-shadow: 0 0 0 1px var(--cyan), 0 0 34px rgba(53, 232, 208, 0.14);
}

.page-about .research-board__summary h3 {
  margin: 0 0 8px;
  font-size: 19px;
  line-height: 1.35;
}

.page-about .research-board__summary p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mint);
}

.page-about .research-board__points {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 9px;
  align-content: start;
}

.page-about .research-board__points li {
  position: relative;
  padding-left: 16px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--white);
}

.page-about .research-board__points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
}

.page-about .research-board__link {
  align-self: start;
}

/* ── 主客场视图 ───────────────────────── */
.page-about .about-split {
  padding: 58px 0;
  background: var(--night);
}

.page-about .split-cards {
  display: grid;
  gap: 14px;
  margin-top: 26px;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .split-card {
  background: linear-gradient(160deg, var(--panel) 0%, var(--ink) 100%);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 22px;
  transition: border-color 0.24s var(--ease);
}

.page-about .split-card:hover {
  border-color: rgba(53, 232, 208, 0.45);
}

.page-about .split-card__tag {
  display: inline-block;
  margin-bottom: 14px;
}

.page-about .split-card h3 {
  margin: 0 0 8px;
  font-size: 17px;
  line-height: 1.4;
}

.page-about .split-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mint);
}

.page-about .split-note {
  margin-top: 18px;
  padding: 20px 22px;
  border-radius: var(--r-lg);
  border: 1px dashed rgba(53, 232, 208, 0.4);
  background: rgba(28, 95, 88, 0.16);
  display: grid;
  gap: 12px;
}

.page-about .split-note p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--white);
}

/* ── 团队 ─────────────────────────────── */
.page-about .about-team {
  padding: 56px 0;
  background: var(--ink);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

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

.page-about .team-intro h2 {
  font-size: clamp(24px, 3.6vw, 36px);
  line-height: 1.2;
  margin: 10px 0 14px;
}

.page-about .team-intro > p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mint);
  max-width: 42ch;
}

.page-about .team-intro__media {
  margin-top: 24px;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line);
}

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

.page-about .team-cards {
  display: grid;
  gap: 12px;
  align-content: start;
}

.page-about .team-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 20px;
  transition: border-color 0.24s var(--ease), box-shadow 0.24s var(--ease);
}

.page-about .team-card:hover {
  border-color: rgba(53, 232, 208, 0.45);
  box-shadow: 0 0 30px rgba(28, 95, 88, 0.4);
}

.page-about .team-card__head {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.page-about .team-card__num {
  font-family: var(--font-num);
  font-size: clamp(44px, 9vw, 64px);
  font-weight: 600;
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: var(--cyan);
  flex: 0 0 auto;
}

.page-about .team-card__title {
  margin: 4px 0 6px;
  font-size: 17px;
  line-height: 1.3;
}

.page-about .team-card__sub {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--mint);
}

.page-about .team-card__trigger {
  margin-top: 16px;
}

.page-about .team-card .disclosure__panel {
  margin-top: 12px;
}

.page-about .team-card .disclosure__panel ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .team-card .disclosure__panel li {
  position: relative;
  padding-left: 15px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--mint);
}

.page-about .team-card .disclosure__panel li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--orange);
}

.page-about .team-card[data-open] {
  border-color: var(--cyan);
}

/* ── 校验 ─────────────────────────────── */
.page-about .about-check {
  padding: 58px 0;
  background: var(--night);
}

.page-about .check-grid {
  display: grid;
  gap: 28px;
  align-items: start;
}

.page-about .check-media {
  border-radius: var(--r-xl);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--panel);
  position: relative;
}

.page-about .check-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 50%, rgba(53, 232, 208, 0.12), transparent 68%);
  pointer-events: none;
}

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

.page-about .check-body h2 {
  font-size: clamp(24px, 3.6vw, 36px);
  line-height: 1.2;
  margin: 10px 0 14px;
}

.page-about .check-body > p {
  margin: 0 0 26px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mint);
  max-width: 44ch;
}

.page-about .check-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .check-steps li {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 14px;
  padding: 16px 0;
  border-top: 1px solid var(--line);
}

.page-about .check-steps li:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .check-steps__num {
  font-family: var(--font-num);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--orange);
  padding-top: 2px;
}

.page-about .check-steps h3 {
  margin: 0 0 6px;
  font-size: 16px;
  line-height: 1.4;
}

.page-about .check-steps p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--mint);
}

/* ── 术语 ─────────────────────────────── */
.page-about .about-glossary {
  padding: 56px 0;
  background: var(--panel);
}

.page-about .glossary {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .glossary__item {
  display: grid;
  gap: 6px;
  padding: 14px 18px;
  border-radius: var(--r-pill);
  border: 1px solid var(--line);
  background: var(--ink);
  transition: border-color 0.24s var(--ease), background 0.24s var(--ease), transform 0.24s var(--ease);
}

.page-about .glossary__item:hover,
.page-about .glossary__item:focus-within {
  border-color: var(--cyan);
  background: rgba(28, 95, 88, 0.3);
  transform: translateX(3px);
}

.page-about .glossary__term {
  font-size: 15px;
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: 0.01em;
}

.page-about .glossary__def {
  font-size: 13px;
  line-height: 1.65;
  color: var(--mint);
}

.page-about .glossary__item:hover .glossary__def,
.page-about .glossary__item:focus-within .glossary__def {
  color: var(--white);
}

.page-about .glossary__note {
  margin: 22px 0 0;
  font-size: 14px;
  line-height: 1.9;
  color: var(--mint);
}

.page-about .glossary__note .link-arrow {
  margin-left: 6px;
}

/* ── 收口 ─────────────────────────────── */
.page-about .about-close {
  padding: 54px 0 20px;
  background: var(--night);
}

.page-about .about-close__inner {
  display: grid;
  gap: 26px;
  padding: 30px 24px;
  border-radius: var(--r-xl);
  border: 1px solid var(--line);
  background: linear-gradient(140deg, var(--ink) 0%, var(--panel) 100%);
}

.page-about .about-close__copy h2 {
  font-size: clamp(24px, 3.8vw, 34px);
  line-height: 1.22;
  margin: 10px 0 12px;
}

.page-about .about-close__copy p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mint);
  max-width: 46ch;
}

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

/* ── 响应式 ───────────────────────────── */
@media (min-width: 600px) {
  .page-about .about-origin__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

  .page-about .glossary__item {
    border-radius: var(--r-lg);
  }

  .page-about .split-note {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
  }

  .page-about .split-note p {
    max-width: 60ch;
  }
}

@media (min-width: 760px) {
  .page-about .research-board {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
    column-gap: 28px;
    padding: 24px 26px;
  }

  .page-about .research-board__link {
    grid-column: 1 / -1;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    column-gap: 56px;
  }

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

  .page-about .about-hero__media img {
    height: 360px;
  }

  .page-about .timeline {
    --tl-year: 132px;
    --tl-gap: 52px;
    margin-top: 40px;
  }

  .page-about .timeline::before {
    left: calc(var(--tl-year) + var(--tl-gap) / 2 - 1px);
    top: 10px;
  }

  .page-about .timeline__item {
    display: grid;
    grid-template-columns: var(--tl-year) minmax(0, 1fr);
    column-gap: var(--tl-gap);
    padding: 0 0 36px 0;
  }

  .page-about .timeline__dot {
    left: calc(var(--tl-year) + var(--tl-gap) / 2 - 8px);
    top: 8px;
  }

  .page-about .timeline__year {
    text-align: right;
    font-size: 32px;
    margin: 0;
    padding-top: 3px;
  }

  .page-about .research-board {
    grid-column: 2;
    grid-row: 1;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    column-gap: 44px;
    align-items: start;
  }

  .page-about .check-grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 6fr);
    column-gap: 48px;
    align-items: center;
  }

  .page-about .about-close__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 38px 40px;
  }
}

@media (min-width: 1100px) {
  .page-about .glossary {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-hero__media img {
    height: 400px;
  }
}