.page-about {
  --about-nav-w: 230px;
  --about-col-gap: clamp(28px, 5vw, 72px);
  --about-pad: clamp(28px, 5vw, 56px);
  background: var(--sand-100);
  color: var(--navy-950);
}

.page-about .about-crumbs {
  padding-top: 20px;
  padding-bottom: 4px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  background: var(--navy-950);
  color: var(--white);
  padding-top: clamp(24px, 4vw, 44px);
  padding-bottom: calc(clamp(44px, 7vw, 84px) + 34px);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -80px;
  right: -12%;
  width: 46%;
  height: 220px;
  background: linear-gradient(180deg, rgba(22, 69, 107, 0.55), rgba(22, 69, 107, 0));
  transform: skewX(-9deg);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 34px;
  background: var(--sand-100);
  clip-path: polygon(0 100%, 100% 0, 100% 100%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__lead {
  max-width: 62ch;
}

.page-about .about-hero .eyebrow {
  color: var(--orange-200);
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-heading);
  font-size: clamp(27px, 4.6vw, 52px);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .about-hero__lede {
  margin: 18px 0 0;
  max-width: 66ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.78;
  color: var(--mist-400);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 20px;
  margin-top: clamp(30px, 5vw, 52px);
  padding-top: 26px;
  border-top: 1px solid var(--line-on-dark);
}

.page-about .about-hero__stats .scoreboard {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 6px;
}

.page-about .about-hero__stats .scoreboard__value {
  font-family: var(--font-mono);
  font-size: clamp(28px, 4.4vw, 44px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: var(--white);
}

.page-about .about-hero__stats .scoreboard__unit {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--orange-500);
}

.page-about .about-hero__stats .scoreboard__label {
  flex-basis: 100%;
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist-400);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  padding-block: clamp(28px, 5vw, 64px);
}

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

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

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  scroll-margin-top: calc(var(--header-h) + 24px);
  padding-block: var(--about-pad);
}

.page-about .about-section + .about-section {
  border-top: 1px solid var(--line-on-light);
}

.page-about .about-section__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 20px;
}

.page-about .about-section__num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--orange-500);
  padding-top: 3px;
}

.page-about .about-section h2 {
  margin: 0;
  font-family: var(--font-heading);
  font-size: clamp(21px, 2.8vw, 31px);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: -0.02em;
  color: var(--navy-950);
}

.page-about .about-section p {
  max-width: var(--read-max);
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--navy-800);
}

.page-about .about-section p:last-of-type {
  margin-bottom: 0;
}

.page-about .about-section a {
  color: var(--orange-500);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.page-about .about-section a:hover,
.page-about .about-section a:focus-visible {
  color: var(--navy-950);
}

.page-about .about-inline-link {
  margin-top: 18px !important;
  padding-left: 14px;
  border-left: 3px solid var(--orange-500);
  font-size: 15px !important;
}

/* ---------- 深色章节 ---------- */
.page-about .about-section--dark {
  position: relative;
  background: var(--navy-800);
  color: var(--sand-100);
  padding-inline: clamp(18px, 3vw, 40px);
  margin-block: clamp(10px, 2.5vw, 32px);
  border-top: 0 !important;
}

.page-about .about-section--dark::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--orange-500);
}

.page-about .about-section--dark h2 {
  color: var(--white);
}

.page-about .about-section--dark p {
  color: var(--sand-300);
}

.page-about .about-section--dark a {
  color: var(--orange-200);
}

.page-about .about-section--dark a:hover,
.page-about .about-section--dark a:focus-visible {
  color: var(--white);
}

/* ---------- 指标标签 ---------- */
.page-about .metric-grid {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  max-width: 640px;
}

.page-about .metric-grid li {
  font-size: 14px;
  line-height: 1.5;
  padding: 9px 12px;
  border: 1px solid var(--sand-300);
  border-left: 3px solid var(--navy-600);
  background: rgba(255, 255, 255, 0.5);
  color: var(--navy-800);
}

.page-about .about-note {
  margin-top: 20px !important;
  font-size: 14px !important;
  color: var(--mist-400) !important;
}

/* ---------- 三组团队卡片 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 26px;
}

.page-about .team-card {
  position: relative;
  padding: 22px 20px 24px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--line-on-dark);
  border-top: 2px solid var(--orange-500);
  backdrop-filter: blur(4px);
}

.page-about .team-card__num {
  font-family: var(--font-mono);
  font-size: clamp(34px, 4.6vw, 46px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.04em;
  font-variant-numeric: tabular-nums;
  color: var(--white);
}

.page-about .team-card__unit {
  margin-left: 6px;
  font-size: 13px;
  font-weight: 700;
  color: var(--orange-500);
}

.page-about .team-card h3 {
  margin: 12px 0 10px;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .team-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--sand-300);
  max-width: none;
}

.page-about .team-card__more {
  margin-top: 16px;
  border-top: 1px solid var(--line-on-dark);
  padding-top: 12px;
}

.page-about .team-card__more summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--orange-200);
}

.page-about .team-card__more summary::-webkit-details-marker {
  display: none;
}

.page-about .team-card__more summary::before {
  content: "+";
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
  color: var(--orange-500);
}

.page-about .team-card__more[open] summary::before {
  content: "\2212";
}

.page-about .team-card__more summary:focus-visible {
  outline: 2px solid var(--orange-500);
  outline-offset: 3px;
}

.page-about .team-card__more ul {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .team-card__more li {
  position: relative;
  padding-left: 14px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--sand-300);
}

.page-about .team-card__more li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 6px;
  height: 1px;
  background: var(--orange-500);
}

/* ---------- 场馆数据条 ---------- */
.page-about .arena-rows {
  display: grid;
  gap: 20px;
  margin-top: 26px;
  padding: 22px 20px;
  background: rgba(12, 35, 56, 0.05);
  border-left: 3px solid var(--navy-600);
}

.page-about .arena-row__label {
  display: block;
  margin-bottom: 10px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--navy-600);
}

.page-about .arena-row .data-bar__meta {
  margin-top: 8px;
  font-size: 13px;
  color: var(--navy-800);
}

/* ---------- 年表 ---------- */
.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 30px 0 0;
  padding: 0 0 0 34px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--sand-300);
}

.page-about .about-timeline__item {
  position: relative;
  padding-bottom: 28px;
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -34px;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--sand-100);
  border: 3px solid var(--orange-500);
  box-sizing: border-box;
}

.page-about .about-timeline__year {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums;
  color: var(--orange-500);
}

.page-about .about-timeline__body h3 {
  margin: 6px 0 8px;
  font-size: 17px;
  font-weight: 800;
  line-height: 1.4;
  color: var(--navy-950);
}

.page-about .about-timeline__body p {
  margin: 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--navy-800);
}

/* ---------- 图片 ---------- */
.page-about .media-frame {
  margin: 30px 0 0;
}

.page-about .media-frame__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--mist-400);
}

.page-about .about-section--dark .media-frame__caption {
  color: var(--mist-400);
}

/* ---------- 结尾动作 ---------- */
.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-actions .btn {
  flex: 0 1 auto;
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-hero::after {
    height: 42px;
  }
}

/* ---------- 桌面：左侧固定目录 ---------- */
@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: var(--about-nav-w) minmax(0, 1fr);
    gap: var(--about-col-gap);
    align-items: start;
  }

  .page-about .about-toc {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 28px);
    padding-left: 18px;
    border-left: 2px solid var(--sand-300);
    max-height: calc(100vh - var(--header-h) - 56px);
    overflow-y: auto;
  }

  .page-about .about-toc__title {
    margin: 0 0 14px;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.16em;
    color: var(--navy-600);
  }

  .page-about .about-toc__list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 2px;
  }

  .page-about .about-toc__link {
    display: flex;
    gap: 10px;
    align-items: baseline;
    padding: 9px 10px 9px 0;
    font-size: 14px;
    line-height: 1.45;
    color: var(--navy-800);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
  }

  .page-about .about-toc__num {
    font-family: var(--font-mono);
    font-size: 12px;
    font-weight: 700;
    color: var(--sand-300);
    font-variant-numeric: tabular-nums;
  }

  .page-about .about-toc__link:hover,
  .page-about .about-toc__link:focus-visible {
    color: var(--orange-500);
    border-bottom-color: var(--orange-500);
    outline: none;
  }

  .page-about .about-toc__link:hover .about-toc__num,
  .page-about .about-toc__link:focus-visible .about-toc__num {
    color: var(--orange-500);
  }

  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
    gap: 16px;
  }

  .page-about .team-card:nth-child(2) {
    margin-top: 26px;
  }

  .page-about .team-card:nth-child(3) {
    margin-top: 56px;
  }

  .page-about .metric-grid {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
}