.page-about {
  --about-rail: 232px;
  --about-cut: 22px;
  background: var(--sand);
  color: var(--ink);
  font-family: var(--font-body);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(6.5rem, 14vw, 10rem) 0 clamp(2.5rem, 6vw, 4rem);
  background:
    radial-gradient(120% 90% at 16% 6%, rgba(30, 122, 140, 0.55), transparent 62%),
    linear-gradient(158deg, var(--teal) 0%, var(--ink-deep) 70%);
  color: var(--sand);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  z-index: 0;
  right: -14%;
  top: -20%;
  width: 66%;
  height: 136%;
  background: linear-gradient(202deg, rgba(255, 90, 31, 0.44), rgba(255, 90, 31, 0) 62%);
  transform: rotate(-9deg);
  pointer-events: none;
}

.page-about .about-hero__media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.page-about .about-hero__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.28;
  filter: saturate(0.62) contrast(1.06);
}

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

.page-about .about-hero .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: rgba(220, 239, 243, 0.7);
}

.page-about .about-hero .breadcrumb__item {
  color: inherit;
  text-decoration: none;
}

.page-about .about-hero .breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: 0.5rem;
  color: rgba(220, 239, 243, 0.42);
}

.page-about .about-hero .breadcrumb__item[aria-current="page"] {
  color: var(--sand);
}

.page-about .about-hero__eyebrow {
  margin: clamp(1.5rem, 4vw, 2.5rem) 0 0;
  color: var(--sand-mid);
}

.page-about .about-hero__title {
  margin: 0.7rem 0 0;
  max-width: 17ch;
  font-size: clamp(2rem, 6.2vw, 4.35rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.022em;
  color: var(--sand);
}

.page-about .about-hero__lede {
  margin: clamp(1.15rem, 3vw, 1.7rem) 0 0;
  max-width: 42em;
  font-size: clamp(0.98rem, 2.1vw, 1.14rem);
  line-height: 1.92;
  color: rgba(220, 239, 243, 0.9);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.1rem 1.25rem;
  margin-top: clamp(2rem, 5vw, 3.25rem);
  padding-top: clamp(1.25rem, 3vw, 1.75rem);
  border-top: 1px solid rgba(220, 239, 243, 0.24);
}

.page-about .about-hero__stat strong {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 4.6vw, 2.9rem);
  font-weight: 700;
  line-height: 1;
  color: var(--sand);
  letter-spacing: -0.02em;
}

.page-about .about-hero__stat span {
  display: block;
  margin-top: 0.5rem;
  font-size: 0.8rem;
  line-height: 1.6;
  letter-spacing: 0.03em;
  color: rgba(220, 239, 243, 0.72);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-items: stretch;
  gap: clamp(1.25rem, 4vw, 3rem);
  padding: clamp(1.75rem, 5vw, 3.25rem) 0 clamp(3rem, 7vw, 5rem);
}

.page-about .about-flow {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: clamp(1.75rem, 5vw, 3.25rem);
}

/* ---------- 左侧章节索引 ---------- */
.page-about .about-toc-wrap {
  min-width: 0;
}

.page-about .about-toc {
  border-bottom: 1px solid rgba(18, 69, 78, 0.16);
}

.page-about .about-toc__list {
  display: flex;
  gap: 0.85rem;
  width: max-content;
  margin: 0;
  padding: 0.65rem 0;
  list-style: none;
}

.page-about .about-toc__link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.04em;
  white-space: nowrap;
  color: var(--teal);
  text-decoration: none;
}

.page-about .about-toc__num {
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--home);
}

.page-about .about-toc__link:hover {
  color: var(--home-deep);
}

/* ---------- 章节画板 ---------- */
.page-about .about-sec {
  position: relative;
  padding-top: clamp(1.75rem, 4.5vw, 2.75rem);
  border-top: 1px solid rgba(18, 69, 78, 0.14);
  scroll-margin-top: calc(var(--header-h) + 2rem);
}

.page-about .about-sec:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-sec__head {
  display: grid;
  gap: 0.45rem;
  margin-bottom: clamp(1.1rem, 3vw, 1.75rem);
}

.page-about .about-sec__head .section-marker {
  display: block;
}

.page-about .about-sec__head .eyebrow {
  margin: 0;
  color: var(--teal-mid);
}

.page-about .about-sec__title {
  margin: 0;
  font-size: clamp(1.45rem, 4vw, 2.3rem);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.012em;
  color: var(--teal);
}

.page-about .about-sec .prose {
  max-width: 38em;
}

.page-about .about-sec .prose p {
  margin: 0 0 1.05rem;
  line-height: 1.9;
}

.page-about .about-sec .prose p:last-child {
  margin-bottom: 0;
}

/* ---------- 赛事层级卡 ---------- */
.page-about .about-tiers {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.9rem;
  margin-top: clamp(1.25rem, 3vw, 2rem);
}

.page-about .about-tier {
  position: relative;
  padding: clamp(1.1rem, 3vw, 1.5rem);
  background: var(--mist);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .about-tier__title {
  margin: 0;
  font-size: 1.18rem;
  font-weight: 800;
  color: var(--teal);
}

.page-about .about-tier__text {
  margin: 0.6rem 0 0;
  font-size: 0.94rem;
  line-height: 1.82;
  color: rgba(20, 25, 28, 0.82);
}

/* ---------- 延伸归档列表 ---------- */
.page-about .about-expand {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.85rem;
  margin: clamp(1.25rem, 3vw, 2rem) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-expand__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.75rem;
  align-items: start;
  padding-bottom: 0.85rem;
  border-bottom: 1px dashed rgba(18, 69, 78, 0.2);
}

.page-about .about-expand__item p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.78;
  color: rgba(20, 25, 28, 0.82);
}

/* ---------- 数字块 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(1.5rem, 3.5vw, 2.25rem);
  background: rgba(18, 69, 78, 0.16);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
  overflow: hidden;
}

.page-about .about-stats__item {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  padding: clamp(1rem, 2.6vw, 1.55rem);
  background: var(--mist);
}

.page-about .about-stats__num {
  font-family: var(--font-mono);
  font-size: clamp(1.7rem, 4.4vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--teal);
}

.page-about .about-stats__num--home {
  color: var(--home);
}

.page-about .about-stats__label {
  font-size: 0.82rem;
  line-height: 1.72;
  color: rgba(20, 25, 28, 0.74);
}

/* ---------- 团队角色 ---------- */
.page-about .about-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.9rem;
  margin-top: clamp(1.25rem, 3vw, 2rem);
}

.page-about .about-role {
  position: relative;
  padding: clamp(1.05rem, 2.8vw, 1.4rem) clamp(1.05rem, 2.8vw, 1.4rem) clamp(1.1rem, 2.8vw, 1.5rem);
  padding-left: calc(clamp(1.05rem, 2.8vw, 1.4rem) + 14px);
  background: rgba(255, 255, 255, 0.55);
  border-left: 4px solid var(--teal-mid);
}

.page-about .about-role:nth-child(2) {
  border-left-color: var(--home);
}

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

.page-about .about-role:nth-child(4) {
  border-left-color: var(--sand-mid);
}

.page-about .about-role__count {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 3.8vw, 2.2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--ink-deep);
}

.page-about .about-role__title {
  margin: 0.45rem 0 0;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--teal);
}

.page-about .about-role__text {
  margin: 0.5rem 0 0;
  font-size: 0.92rem;
  line-height: 1.8;
  color: rgba(20, 25, 28, 0.8);
}

/* ---------- 配图 ---------- */
.page-about .about-figure {
  margin: clamp(1.5rem, 4vw, 2.25rem) 0 0;
}

.page-about .about-figure__caption {
  margin-top: 0.7rem;
  font-size: 0.8rem;
  letter-spacing: 0.02em;
  color: rgba(20, 25, 28, 0.6);
}

.page-about .about-figure--texture {
  margin-top: clamp(1.75rem, 4.5vw, 2.75rem);
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  margin: clamp(1.5rem, 4vw, 2.25rem) 0 0;
  padding: 0 0 0 1.55rem;
  list-style: none;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 0.7rem;
  bottom: 0.7rem;
  width: 2px;
  background: linear-gradient(180deg, var(--home), var(--teal-mid) 48%, var(--sand-mid));
}

.page-about .about-timeline__item {
  position: relative;
  padding-bottom: clamp(1.35rem, 3.5vw, 2.1rem);
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -1.55rem;
  top: 0.5rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--sand);
  border: 3px solid var(--home);
}

.page-about .about-timeline__item:nth-child(3)::before {
  border-color: var(--teal-mid);
}

.page-about .about-timeline__item:nth-child(5)::before {
  border-color: var(--up);
}

.page-about .about-timeline__year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--home-deep);
}

.page-about .about-timeline__title {
  margin: 0.35rem 0 0;
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--teal);
}

.page-about .about-timeline__text {
  margin: 0.45rem 0 0;
  max-width: 34em;
  font-size: 0.93rem;
  line-height: 1.82;
  color: rgba(20, 25, 28, 0.8);
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: clamp(1.25rem, 3vw, 2rem) 0 0;
  border-top: 1px solid rgba(18, 69, 78, 0.16);
}

.page-about .about-partner {
  padding: clamp(1rem, 2.8vw, 1.4rem) 0;
  border-bottom: 1px solid rgba(18, 69, 78, 0.16);
}

.page-about .about-partner__name {
  font-family: var(--font-mono);
  font-size: 0.86rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--teal);
}

.page-about .about-partner__text {
  margin: 0.55rem 0 0;
  max-width: 36em;
  font-size: 0.93rem;
  line-height: 1.82;
  color: rgba(20, 25, 28, 0.82);
}

/* ---------- 四件事 ---------- */
.page-about .about-sec--principles {
  padding-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-principles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(0.9rem, 2.6vw, 1.35rem);
  margin: clamp(1.25rem, 3vw, 2rem) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-principle {
  position: relative;
  padding: clamp(1.15rem, 3vw, 1.6rem);
  background: linear-gradient(140deg, rgba(220, 239, 243, 0.9), rgba(231, 207, 169, 0.42));
  clip-path: polygon(var(--about-cut) 0, 100% 0, 100% 100%, 0 100%, 0 var(--about-cut));
}

.page-about .about-principle__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--home);
}

.page-about .about-principle__title {
  margin: 0.6rem 0 0;
  font-size: 1.08rem;
  font-weight: 800;
  color: var(--teal);
}

.page-about .about-principle__text {
  margin: 0.5rem 0 0;
  font-size: 0.92rem;
  line-height: 1.82;
  color: rgba(20, 25, 28, 0.82);
}

/* ---------- 收尾入口 ---------- */
.page-about .about-cta {
  margin-top: clamp(0.5rem, 2vw, 1rem);
}

.page-about .about-cta__inner {
  position: relative;
  padding: clamp(1.6rem, 5vw, 3rem);
  background:
    radial-gradient(90% 140% at 88% 0%, rgba(255, 90, 31, 0.36), transparent 58%),
    linear-gradient(120deg, var(--teal) 0%, var(--ink-deep) 82%);
  color: var(--sand);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 34px), calc(100% - 34px) 100%, 0 100%);
}

.page-about .about-cta__title {
  margin: 0;
  font-size: clamp(1.3rem, 3.6vw, 2rem);
  font-weight: 800;
  line-height: 1.25;
  color: var(--sand);
}

.page-about .about-cta__text {
  margin: 0.85rem 0 0;
  max-width: 40em;
  font-size: 0.96rem;
  line-height: 1.88;
  color: rgba(220, 239, 243, 0.86);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: clamp(1.25rem, 3vw, 1.85rem);
}

.page-about .about-cta__actions .btn {
  text-decoration: none;
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1.25rem;
  }

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

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

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

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 3.5rem);
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--header-h) + 2rem);
    border-bottom: 0;
  }

  .page-about .about-toc__list {
    display: block;
    position: relative;
    width: auto;
    padding: 0.25rem 0 0.25rem 1.15rem;
    border-bottom: 0;
  }

  .page-about .about-toc__list::before {
    content: "";
    position: absolute;
    left: 1px;
    top: 0.6rem;
    bottom: 0.6rem;
    width: 2px;
    background: linear-gradient(180deg, var(--teal-mid), var(--sand-mid));
  }

  .page-about .about-toc__item {
    position: relative;
  }

  .page-about .about-toc__item::before {
    content: "";
    position: absolute;
    left: -1.15rem;
    top: 0.72rem;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--sand);
    border: 2px solid var(--teal-mid);
  }

  .page-about .about-toc__link {
    display: block;
    padding: 0.42rem 0;
    font-size: 0.78rem;
  }

  .page-about .about-toc__num {
    margin-right: 0.4rem;
  }

  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-partners {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(1.5rem, 4vw, 3rem);
  }
}

@media (min-width: 1200px) {
  .page-about .about-flow {
    padding-left: clamp(0.5rem, 1.5vw, 1.5rem);
  }

  .page-about .about-principles {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-hero::after {
    transform: none;
  }
}