.page-about {
  --about-ink-soft: rgba(26, 31, 41, 0.74);
  --about-cool-soft: rgba(231, 237, 245, 0.7);
  --about-gap: clamp(22px, 3.4vw, 44px);
}

.page-about [id] {
  scroll-margin-top: 96px;
}

/* ---------- 首屏：纸白阅读区 + 图 + 年份刻度 ---------- */
.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  align-items: start;
}

.page-about .about-lede {
  position: relative;
  background: var(--paper);
  color: var(--ink);
  padding: clamp(24px, 3.6vw, 48px);
}

.page-about .about-lede::before,
.page-about .about-lede::after {
  content: "";
  position: absolute;
  width: 20px;
  height: 20px;
  border: 2px solid var(--gold);
  pointer-events: none;
}

.page-about .about-lede::before {
  top: 9px;
  left: 9px;
  border-right: 0;
  border-bottom: 0;
}

.page-about .about-lede::after {
  right: 9px;
  bottom: 9px;
  border-left: 0;
  border-top: 0;
}

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin-bottom: 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--slate);
}

.page-about .breadcrumb a {
  color: var(--lake);
  text-decoration: none;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  text-decoration: underline;
}

.page-about .about-lede .eyebrow {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--lake);
}

.page-about .about-lede h1 {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-size: clamp(27px, 4.4vw, 44px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.page-about .about-lede__lead {
  margin: 0 0 16px;
  max-width: 52ch;
  font-size: 17px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .about-copy {
  margin: 0 0 14px;
  max-width: 52ch;
  font-size: 15px;
  line-height: 1.82;
  color: var(--about-ink-soft);
}

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

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

.page-about .about-figure {
  margin: 0;
  border: 1px solid var(--rule-strong);
  background: var(--indigo);
  overflow: hidden;
}

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

/* 年份刻度 */
.page-about .year-rail {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .year-rail__item {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 11px;
  border: 1px solid var(--rule);
  color: var(--cool-white);
  text-decoration: none;
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .year-rail__item:hover,
.page-about .year-rail__item:focus-visible {
  border-color: var(--gold);
  background: rgba(232, 181, 75, 0.1);
}

.page-about .year-rail__y {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .year-rail__note {
  font-size: 12px;
  color: var(--about-cool-soft);
}

/* ---------- 通用栏目头 ---------- */
.page-about .sec-head {
  max-width: 62ch;
  margin-bottom: clamp(22px, 3vw, 38px);
}

.page-about .sec-head .eyebrow {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--lake);
}

.page-about .sec-head h2,
.page-about .handbook__body h2 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: clamp(23px, 3vw, 34px);
  line-height: 1.24;
  letter-spacing: -0.02em;
  color: var(--cool-white);
}

.page-about .sec-head p {
  margin: 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--about-cool-soft);
}

.page-about .sec-head a,
.page-about .partner-note a {
  color: var(--gold);
  text-decoration: none;
  border-bottom: 1px solid rgba(232, 181, 75, 0.45);
}

.page-about .sec-head a:hover,
.page-about .partner-note a:hover {
  border-bottom-color: var(--gold);
}

/* ---------- 三条主线：目录行 ---------- */
.page-about .line-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--rule-strong);
}

.page-about .line-row {
  position: relative;
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 4px 14px;
  padding: 20px 0;
  border-bottom: 1px solid var(--rule);
}

.page-about .line-row__idx {
  padding-top: 4px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .line-row__body h3 {
  margin: 0 0 7px;
  font-family: var(--font-display);
  font-size: 19px;
  letter-spacing: -0.01em;
}

.page-about .line-row__body h3 a {
  color: var(--cool-white);
  text-decoration: none;
  border-bottom: 1px solid rgba(232, 181, 75, 0.4);
  padding-bottom: 2px;
}

.page-about .line-row__body h3 a:hover,
.page-about .line-row__body h3 a:focus-visible {
  color: var(--gold);
  border-bottom-color: var(--gold);
}

.page-about .line-row__body p {
  margin: 0;
  max-width: 66ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-cool-soft);
}

.page-about .line-row__body p a {
  color: var(--lake);
  text-decoration: none;
  border-bottom: 1px solid rgba(44, 138, 138, 0.55);
}

.page-about .line-row__body p a:hover {
  color: var(--gold);
  border-bottom-color: var(--gold);
}

.page-about .line-row__go {
  display: none;
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  align-items: start;
}

.page-about .crew {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .crew__item {
  border-top: 2px solid var(--rule-strong);
  padding-top: 14px;
}

.page-about .crew__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 28px;
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--gold);
}

.page-about .crew__num small {
  margin-left: 6px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--slate);
}

.page-about .crew__item h3 {
  margin: 9px 0 6px;
  font-size: 16px;
  letter-spacing: 0.02em;
  color: var(--cool-white);
}

.page-about .crew__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--about-cool-soft);
}

.page-about .about-figure--team {
  margin-top: 4px;
}

/* ---------- 版本演进：斜切时间条 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .tl-node {
  position: relative;
  background: var(--indigo);
  border-left: 3px solid var(--orange);
  padding: 18px 20px 20px;
  color: var(--cool-white);
  transition: background var(--dur) var(--ease);
}

.page-about .tl-node__ver {
  display: inline-block;
  margin-bottom: 8px;
  padding: 2px 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--star-black);
  background: var(--gold);
}

.page-about .tl-node__year {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 22px;
  letter-spacing: 0.06em;
  color: var(--gold);
}

.page-about .tl-node h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: -0.01em;
  color: var(--cool-white);
}

.page-about .tl-node p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--about-cool-soft);
}

.page-about .tl-node:hover {
  background: #17325a;
}

/* ---------- 合作 ---------- */
.page-about .partner-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  align-items: start;
}

.page-about .partner-note {
  margin: 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-cool-soft);
}

.page-about .matrix {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 7px;
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
}

.page-about .matrix__cell {
  position: relative;
  aspect-ratio: 1 / 1;
  background: var(--indigo);
  border: 1px solid var(--rule-strong);
  transition: transform var(--dur) var(--ease);
}

.page-about .matrix__cell--org {
  border-color: rgba(232, 181, 75, 0.55);
}

.page-about .matrix__cell--edu {
  border-color: rgba(44, 138, 138, 0.8);
}

.page-about .matrix__cell:hover {
  transform: translateY(-2px);
}

.page-about .matrix__tag {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 3px;
  font-size: 10px;
  line-height: 1.25;
  text-align: center;
  letter-spacing: 0.02em;
  color: var(--star-black);
  background: var(--gold);
  opacity: 0;
  transition: opacity var(--dur) var(--ease);
}

.page-about .matrix__cell--edu .matrix__tag {
  background: var(--lake);
  color: #ffffff;
}

.page-about .matrix__cell:hover .matrix__tag,
.page-about .matrix__cell:focus-within .matrix__tag {
  opacity: 1;
}

.page-about .matrix-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
  color: var(--about-cool-soft);
}

.page-about .matrix-legend li {
  display: flex;
  align-items: center;
  gap: 7px;
}

.page-about .swatch {
  display: inline-block;
  width: 11px;
  height: 11px;
}

.page-about .swatch--org {
  background: var(--gold);
}

.page-about .swatch--edu {
  background: var(--lake);
}

/* ---------- 赛季手册 ---------- */
.page-about .handbook {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 36px);
}

.page-about .handbook__body {
  max-width: 64ch;
}

.page-about .handbook__body .eyebrow {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--lake);
}

.page-about .handbook__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--about-cool-soft);
}

.page-about .handbook__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* ---------- 断点 ---------- */
@media (min-width: 600px) {
  .page-about .crew {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 820px) {
  .page-about .line-row {
    grid-template-columns: 64px minmax(0, 1fr) 36px;
    align-items: start;
    padding: 24px 6px 24px 34px;
  }

  .page-about .line-row::before {
    content: "";
    position: absolute;
    left: 8px;
    top: 32px;
    width: 0;
    height: 0;
    border-left: 9px solid var(--gold);
    border-top: 6px solid transparent;
    border-bottom: 6px solid transparent;
    opacity: 0;
    transform: translateX(-7px);
    transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
  }

  .page-about .line-row:hover::before,
  .page-about .line-row:focus-within::before {
    opacity: 1;
    transform: translateX(0);
  }

  .page-about .line-row:hover .line-row__body h3 a,
  .page-about .line-row:focus-within .line-row__body h3 a {
    color: var(--gold);
    border-bottom-color: var(--gold);
  }

  .page-about .line-row__idx {
    padding-top: 5px;
    font-size: 14px;
  }

  .page-about .line-row__body h3 {
    font-size: 21px;
  }

  .page-about .line-row__go {
    display: block;
    justify-self: end;
    font-family: var(--font-mono);
    font-size: 16px;
    color: var(--slate);
    transition: color var(--dur) var(--ease), transform var(--dur) var(--ease);
  }

  .page-about .line-row:hover .line-row__go {
    color: var(--gold);
    transform: translateX(4px);
  }
}

@media (min-width: 900px) {
  .page-about .timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 10px;
    padding-top: 8px;
  }

  .page-about .tl-node {
    transform: skewX(-8deg);
    border-left: 0;
    border-top: 3px solid var(--orange);
    padding: 22px 22px 26px;
    min-height: 236px;
  }

  .page-about .tl-node__inner {
    transform: skewX(8deg);
  }

  .page-about .partner-grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
  }

  .page-about .matrix {
    max-width: 460px;
  }
}

@media (min-width: 1000px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
  }

  .page-about .about-hero__side {
    gap: 22px;
  }

  .page-about .year-rail {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 15px;
    padding-left: 18px;
    border-left: 1px solid var(--rule-strong);
  }

  .page-about .year-rail__item {
    position: relative;
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
    padding: 0;
    border: 0;
    background: none;
  }

  .page-about .year-rail__item::before {
    content: "";
    position: absolute;
    left: -22px;
    top: 6px;
    width: 9px;
    height: 9px;
    background: var(--gold);
    transform: rotate(45deg);
    transition: background var(--dur) var(--ease);
  }

  .page-about .year-rail__item:hover,
  .page-about .year-rail__item:focus-visible {
    background: none;
  }

  .page-about .year-rail__item:hover::before,
  .page-about .year-rail__item:focus-visible::before {
    background: var(--orange);
  }

  .page-about .year-rail__note {
    font-size: 13px;
  }

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

  .page-about .about-figure--team {
    position: sticky;
    top: 108px;
  }

  .page-about .handbook {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: center;
  }
}

@media (min-width: 1180px) {
  .page-about .about-lede {
    padding: 52px 56px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .matrix__cell,
  .page-about .line-row__go,
  .page-about .tl-node {
    transition: none;
  }

  .page-about .matrix__cell:hover {
    transform: none;
  }

  .page-about .tl-node {
    transform: none;
  }

  .page-about .tl-node__inner {
    transform: none;
  }
}