.page-about {
  --about-axis: 118px;
  --about-gap: clamp(20px, 3vw, 42px);
  --about-sticky: calc(var(--header-row) + 106px);
}

.page-about .shell {
  padding-block: clamp(26px, 5vw, 58px) clamp(44px, 6vw, 96px);
}

/* ---------- 首屏 ---------- */
.page-about__hero {
  max-width: 940px;
  padding-bottom: clamp(26px, 4vw, 50px);
  border-bottom: 1px solid var(--grid);
}

.page-about__hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-size: clamp(29px, 6.2vw, 60px);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -0.015em;
  color: var(--white);
}

.page-about__lede {
  margin: 18px 0 0;
  max-width: 46em;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 时间轴章节 ---------- */
.page-about__section {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  padding-block: clamp(30px, 5vw, 62px);
  border-bottom: 1px solid var(--grid-soft);
}

.page-about__section:last-of-type {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about__axis {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--grid);
  transition: border-color 0.35s var(--ease);
}

.page-about__num {
  font-size: clamp(23px, 3vw, 33px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--muted);
  opacity: 0.45;
  transition: color 0.35s var(--ease), opacity 0.35s var(--ease);
}

.page-about__section[data-active="true"] .page-about__num {
  color: var(--orange);
  opacity: 1;
}

.page-about__section[data-active="true"] .page-about__axis {
  border-bottom-color: var(--orange);
}

.page-about__section[data-active="true"] .page-about__axis .label {
  color: var(--white);
}

.page-about__body > * + * {
  margin-top: 16px;
}

.page-about__body h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(21px, 3.6vw, 38px);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about__body p {
  margin: 0;
  max-width: 44em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about__rule {
  width: 68px;
  height: 3px;
  background: var(--orange);
  transform: skewX(-20deg);
  margin-bottom: 18px;
}

.page-about__aside {
  padding-left: 14px;
  border-left: 2px solid var(--grid);
  font-size: 14px;
  color: var(--muted);
}

.page-about__aside a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(61, 123, 255, 0.4);
}

.page-about__aside a:hover {
  color: var(--orange);
  border-bottom-color: var(--orange);
}

/* ---------- 岗位分工 ---------- */
.page-about__roles {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--grid);
}

.page-about__roles li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px solid var(--grid-soft);
}

.page-about__roles strong {
  font-size: 15px;
  font-weight: 700;
  color: var(--white);
  letter-spacing: 0.01em;
}

.page-about__roles span {
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 图片 ---------- */
.page-about__figure {
  margin: 22px 0 0;
  border: 1px solid var(--grid);
  background: var(--panel-deep);
}

.page-about__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  filter: saturate(0.82) brightness(0.92) contrast(1.04);
}

.page-about__figure figcaption {
  margin: 0;
  padding: 10px 13px;
  border-top: 1px solid var(--grid);
  font-size: 12px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 联赛覆盖 ---------- */
.page-about__leagues {
  display: grid;
  gap: 22px;
  margin-top: 6px;
}

.league-group__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--grid);
}

.league-group__count {
  font-size: 18px;
  font-weight: 700;
  color: var(--orange);
}

.league-chips {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(132px, 1fr));
  gap: 6px;
  margin-top: 12px;
}

.chip {
  display: block;
  padding: 9px 11px;
  border: 1px solid var(--grid);
  background: rgba(12, 20, 36, 0.7);
  font-size: 13px;
  line-height: 1.4;
  color: var(--muted);
  transition: border-color 0.22s var(--ease), color 0.22s var(--ease);
}

.chip:hover {
  border-color: var(--orange);
  color: var(--white);
}

/* ---------- 版本演进 ---------- */
.page-about__chart-wrap {
  margin-top: 4px;
  padding: 12px 10px 4px;
  border: 1px solid var(--grid);
  background: var(--panel-deep);
}

.page-about__chart {
  display: block;
  width: 100%;
  height: auto;
}

.page-about__releases {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--grid);
}

.page-about__releases li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 5px;
  padding: 14px 0;
  border-bottom: 1px solid var(--grid-soft);
}

.page-about__releases .ver {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--orange);
}

.page-about__releases li > span:last-child {
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 规模数据条 ---------- */
.page-about__stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(148px, 1fr));
  gap: 1px;
  background: var(--grid);
  border: 1px solid var(--grid);
  margin-top: 6px;
}

.page-about__stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 16px;
  background: var(--panel);
}

.page-about__stat .num {
  font-size: clamp(23px, 3vw, 33px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about__stat .unit {
  margin-left: 3px;
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 500;
  color: var(--muted);
}

/* ---------- 合作路径 ---------- */
.page-about__paths {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 6px;
}

.page-about__paths .panel__body > * + * {
  margin-top: 12px;
}

.page-about__paths h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 800;
  line-height: 1.3;
  color: var(--white);
}

.page-about__paths p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about__paths .btn {
  margin-top: 4px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about__roles li {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 16px;
    align-items: baseline;
  }

  .page-about__releases li {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 18px;
    align-items: baseline;
  }

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

@media (min-width: 900px) {
  .page-about__section {
    grid-template-columns: var(--about-axis) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about__axis {
    position: sticky;
    top: var(--about-sticky);
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 0 0 0 18px;
    border-bottom: 0;
    border-left: 1px solid var(--grid);
  }

  .page-about__section[data-active="true"] .page-about__axis {
    border-left-color: var(--orange);
  }

  .page-about__axis .label {
    font-size: 11px;
    line-height: 1.5;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .page-about__num,
  .page-about .page-about__axis,
  .page-about .chip {
    transition: none;
  }
}