.page-about {
  --about-axis-w: 136px;
  --about-axis-gap: 40px;
  --about-scroll-gap: 32px;
}

/* ---------- 页头 ---------- */
.page-about .about-head {
  display: grid;
  gap: 28px;
  padding-block: 32px 40px;
  border-bottom: 1px solid var(--line-color);
}

@media (min-width: 960px) {
  .page-about .about-head {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 56px;
    align-items: end;
    padding-block: 48px 56px;
  }
}

.page-about .page-head__title {
  margin: 12px 0 0;
  font-size: clamp(34px, 5.2vw, 76px);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.06;
}

.page-about .page-head__lead {
  margin: 18px 0 0;
  max-width: 46em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-soft);
}

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

.page-about .about-facts > li {
  background: var(--paper-2);
  padding: 18px 20px;
}

.page-about .about-facts__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--milan-red);
  font-variant-numeric: tabular-nums;
}

.page-about .about-facts__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--ink-soft);
}

/* ---------- 长卷骨架 ---------- */
.page-about .about-scroll {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-scroll-gap);
  padding-block: 36px 72px;
}

@media (min-width: 1024px) {
  .page-about .about-scroll {
    grid-template-columns: var(--about-axis-w) minmax(0, 1fr);
    column-gap: var(--about-axis-gap);
    padding-block: 56px 96px;
  }
}

/* ---------- 年份刻度轴 ---------- */
.page-about .era-axis {
  position: static;
}

.page-about .era-axis__mono {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--grey);
}

.page-about .era-axis__list {
  display: flex;
  gap: 10px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .era-axis__link {
  display: block;
  flex: 0 0 auto;
  padding: 8px 12px;
  border: 1px solid var(--line-color);
  text-decoration: none;
  color: var(--ink);
  transition: border-color 160ms var(--ease), background-color 160ms var(--ease);
}

.page-about .era-axis__link:hover,
.page-about .era-axis__link:focus-visible {
  border-color: var(--milan-red);
  background: var(--paper-2);
  outline: none;
}

.page-about .era-axis__year {
  display: block;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.page-about .era-axis__tag {
  display: block;
  margin-top: 2px;
  font-size: 11px;
  color: var(--grey);
  white-space: nowrap;
}

@media (min-width: 1024px) {
  .page-about .era-axis {
    position: sticky;
    top: calc(var(--header-h) + 32px);
    align-self: start;
  }

  .page-about .era-axis__list {
    display: block;
    overflow: visible;
    padding: 0 0 0 22px;
    position: relative;
  }

  .page-about .era-axis__list::before {
    content: "";
    position: absolute;
    left: 5px;
    top: 14px;
    bottom: 14px;
    width: 1px;
    background: var(--line-color);
  }

  .page-about .era-axis__link {
    position: relative;
    border: 0;
    padding: 6px 0 12px;
    background: none;
  }

  .page-about .era-axis__link::before {
    content: "";
    position: absolute;
    left: -22px;
    top: 8px;
    width: 11px;
    height: 11px;
    border-radius: 50%;
    border: 1px solid var(--line-color);
    background: var(--paper);
    transition: background-color 160ms var(--ease), border-color 160ms var(--ease);
  }

  .page-about .era-axis__link:hover,
  .page-about .era-axis__link:focus-visible {
    background: none;
  }

  .page-about .era-axis__link:hover::before,
  .page-about .era-axis__link:focus-visible::before {
    background: var(--milan-red);
    border-color: var(--milan-red);
  }

  .page-about .era-axis__link:hover .era-axis__year,
  .page-about .era-axis__link:focus-visible .era-axis__year {
    color: var(--milan-red);
  }

  .page-about .era-axis__tag {
    white-space: normal;
  }
}

/* ---------- 展区 ---------- */
.page-about .exhibit {
  padding-block: 0 8px;
}

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

@media (min-width: 1024px) {
  .page-about .exhibit + .exhibit {
    padding-top: 72px;
  }
}

.page-about .exhibit .section__title {
  font-size: clamp(24px, 3.1vw, 40px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
}

.page-about .exhibit .section__note {
  max-width: 60ch;
  color: var(--ink-soft);
}

.page-about .exhibit .grid {
  margin-top: 28px;
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  position: relative;
  margin: 0;
  padding: 4px 0 0 34px;
  list-style: none;
}

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

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

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

.page-about .timeline__dot {
  position: absolute;
  left: -34px;
  top: 6px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 2px solid var(--milan-red);
  background: var(--paper);
}

.page-about .timeline__meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--ember);
  font-variant-numeric: tabular-nums;
}

.page-about .timeline__title {
  margin: 6px 0 8px;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .timeline__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* ---------- 两条主线 ---------- */
.page-about .duo-grid {
  gap: 16px;
}

.page-about .duo-card {
  border-top: 3px solid var(--ink);
  transition: border-color 160ms var(--ease), transform 160ms var(--ease);
}

.page-about .duo-card--read {
  border-top-color: var(--milan-red);
}

.page-about .duo-card--compare {
  border-top-color: var(--tech-blue);
}

.page-about .duo-card:hover,
.page-about .duo-card:focus-within {
  transform: translateY(-3px);
}

.page-about .duo-flow {
  margin: 22px 0 0;
  padding-left: 18px;
  border-left: 2px solid var(--ember);
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  max-width: 68ch;
}

.page-about .media-frame--wide {
  margin-top: 30px;
}

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

/* ---------- 团队矩阵 ---------- */
.page-about .team-matrix {
  display: grid;
  gap: 1px;
  margin-top: 28px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

@media (min-width: 780px) {
  .page-about .team-matrix {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .team-block {
  background: var(--paper);
  padding: 26px 22px 30px;
  border-top: 3px solid var(--ink);
  transition: background-color 160ms var(--ease);
}

.page-about .team-block--write {
  border-top-color: var(--milan-red);
}

.page-about .team-block--data {
  border-top-color: var(--tech-blue);
}

.page-about .team-block--build {
  border-top-color: var(--ember);
}

.page-about .team-block:hover,
.page-about .team-block:focus-within {
  background: var(--paper-2);
}

.page-about .team-block__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--grey);
}

.page-about .team-block__title {
  margin: 10px 0 10px;
  font-size: 19px;
  font-weight: 800;
}

.page-about .team-block__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* ---------- 比赛周节拍 ---------- */
.page-about .weekline {
  display: grid;
  gap: 0;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-color);
}

@media (min-width: 900px) {
  .page-about .weekline {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
}

.page-about .weekline__step {
  position: relative;
  padding: 26px 18px 24px 0;
  border-bottom: 1px solid var(--line-soft);
}

@media (min-width: 900px) {
  .page-about .weekline__step {
    padding: 26px 20px 8px 0;
    border-bottom: 0;
    border-right: 1px solid var(--line-soft);
  }

  .page-about .weekline__step:last-child {
    border-right: 0;
    padding-right: 0;
  }

  .page-about .weekline__step:not(:first-child) {
    padding-left: 20px;
  }
}

.page-about .weekline__step::before {
  content: "";
  position: absolute;
  top: -5px;
  left: 0;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ember);
}

@media (min-width: 900px) {
  .page-about .weekline__step:not(:first-child)::before {
    left: 20px;
  }
}

.page-about .weekline__time {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--ink);
}

.page-about .weekline__title {
  margin: 8px 0 8px;
  font-size: 16px;
  font-weight: 800;
}

.page-about .weekline__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-soft);
}

/* ---------- 合作生态 ---------- */
.page-about .partners {
  display: grid;
  gap: 1px;
  margin-top: 28px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

@media (min-width: 780px) {
  .page-about .partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .partner {
  background: var(--paper-2);
  padding: 26px 22px 30px;
  border-left: 2px solid var(--tech-blue);
}

.page-about .partner:nth-child(2) {
  border-left-color: var(--milan-red);
}

.page-about .partner:nth-child(3) {
  border-left-color: var(--ember);
}

.page-about .partner__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 40px;
  font-weight: 700;
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.page-about .partner__title {
  margin: 8px 0 10px;
  font-size: 17px;
  font-weight: 800;
}

.page-about .partner__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* ---------- 服务对象 ---------- */
.page-about .usage {
  height: 100%;
  padding: 22px 22px 26px;
  background: var(--paper-2);
  border-left: 3px solid var(--milan-red);
}

.page-about .usage--light {
  border-left-color: var(--tech-blue);
  background: var(--paper);
  border: 1px solid var(--line-color);
  border-left: 3px solid var(--tech-blue);
}

.page-about .usage__title {
  margin: 0 0 12px;
  font-size: 19px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .usage__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-soft);
}

.page-about .about-day {
  margin-top: 28px;
  padding: 26px 24px 28px;
  background: var(--ink);
  color: var(--paper);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .about-day__mono {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--ember);
  font-variant-numeric: tabular-nums;
}

.page-about .about-day__title {
  margin: 12px 0 12px;
  font-size: 21px;
  font-weight: 800;
  line-height: 1.3;
}

.page-about .about-day__text {
  margin: 0;
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.9;
  color: rgba(244, 238, 227, .84);
}

/* ---------- 结尾入口 ---------- */
.page-about .about-cta {
  margin-top: 12px;
  padding-top: 36px;
  border-top: 2px solid var(--milan-red);
}

.page-about .about-cta__title {
  margin: 0;
  font-size: clamp(22px, 2.8vw, 32px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.page-about .about-cta__text {
  margin: 14px 0 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-soft);
}

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

@media (prefers-reduced-motion: reduce) {
  .page-about .duo-card,
  .page-about .team-block,
  .page-about .era-axis__link,
  .page-about .era-axis__link::before {
    transition: none;
  }

  .page-about .duo-card:hover,
  .page-about .duo-card:focus-within {
    transform: none;
  }
}
</main>