.page-about {
  --about-lead: var(--deep);
  --about-mute: rgba(246, 248, 251, 0.74);
  background: var(--ice);
  color: var(--ink);
}

.page-about .section {
  padding-block: clamp(3rem, 7vw, 5.75rem);
}

.page-about a:focus-visible,
.page-about button:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  color: var(--ice);
  background:
    radial-gradient(120% 80% at 88% 0%, rgba(46, 111, 158, 0.4), transparent 62%),
    linear-gradient(155deg, var(--deep) 0%, var(--night) 100%);
  padding-block: clamp(1.25rem, 4vw, 2.25rem) clamp(2.75rem, 6vw, 4.5rem);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -12%;
  bottom: -22%;
  width: 78%;
  height: 62%;
  background: linear-gradient(90deg, rgba(216, 169, 78, 0.16), transparent 72%);
  transform: rotate(-9deg);
  pointer-events: none;
}

.page-about .about-crumb {
  position: relative;
  z-index: 1;
  margin-bottom: clamp(1.75rem, 4vw, 3rem);
}

.page-about .about-crumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
}

.page-about .about-crumb li {
  color: rgba(246, 248, 251, 0.6);
}

.page-about .about-crumb li + li::before {
  content: "/";
  margin-right: 0.5rem;
  color: var(--gold);
}

.page-about .about-crumb a {
  color: var(--ice);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-crumb a:hover {
  color: var(--gold-soft);
  border-bottom-color: var(--gold);
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(1.75rem, 5vw, 3rem);
  align-items: end;
}

.page-about .about-hero h1 {
  margin: 0.6rem 0 0;
  font-size: clamp(2.15rem, 6.2vw, 4.3rem);
  font-weight: 300;
  line-height: 1.1;
  letter-spacing: -0.02em;
  max-width: 15em;
}

.page-about .about-hero .lede {
  margin: 1.35rem 0 0;
  max-width: 33em;
  font-size: clamp(0.98rem, 1.6vw, 1.1rem);
  line-height: 1.85;
  color: var(--about-mute);
}

.page-about .about-hero__meta {
  display: inline-block;
  margin: 1.6rem 0 0;
  padding-top: 0.85rem;
  border-top: 1px solid rgba(216, 169, 78, 0.34);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: var(--gold-soft);
}

.page-about .about-hero__figure {
  margin: 0;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
  border: 1px solid rgba(216, 169, 78, 0.3);
  border-radius: 2px;
}

.page-about .about-hero__figure figcaption {
  margin-top: 0.7rem;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: rgba(246, 248, 251, 0.56);
}

/* ---------- 缘起 ---------- */
.page-about .about-origin {
  background: var(--ice);
  color: var(--ink);
}

.page-about .about-origin__grid {
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-origin__label {
  margin: 0;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-origin__quote {
  margin: 0.85rem 0 0;
  padding-left: 1rem;
  border-left: 2px solid var(--gold);
  font-size: clamp(1.45rem, 3.2vw, 2rem);
  font-weight: 300;
  line-height: 1.32;
  letter-spacing: -0.01em;
  color: var(--deep);
}

.page-about .about-origin__body h2 {
  margin: 0;
  font-size: clamp(1.55rem, 3.4vw, 2.3rem);
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--deep);
}

.page-about .about-origin__body p {
  margin: 1.1rem 0 0;
  font-size: 0.97rem;
  line-height: 1.85;
  color: rgba(20, 36, 59, 0.82);
}

.page-about .about-origin__list {
  margin: 1.85rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.95rem;
}

.page-about .about-origin__list li {
  display: grid;
  grid-template-columns: 6.5rem minmax(0, 1fr);
  gap: 0.9rem;
  align-items: baseline;
  padding-top: 0.9rem;
  border-top: 1px solid rgba(42, 74, 107, 0.18);
  font-size: 0.92rem;
  line-height: 1.7;
  color: rgba(20, 36, 59, 0.78);
}

.page-about .about-origin__list .mono {
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  color: var(--ember);
}

/* ---------- 通用小节标题 ---------- */
.page-about .about-sec-head {
  max-width: 44rem;
  margin-bottom: clamp(1.75rem, 4vw, 2.75rem);
}

.page-about .about-sec-head h2 {
  margin: 0.5rem 0 0;
  font-size: clamp(1.65rem, 3.8vw, 2.5rem);
  font-weight: 600;
  line-height: 1.22;
  letter-spacing: -0.01em;
}

.page-about .about-sec-head__note {
  margin: 0.9rem 0 0;
  font-size: 0.94rem;
  line-height: 1.8;
  color: inherit;
  opacity: 0.72;
}

/* ---------- 观赛时刻 ---------- */
.page-about .about-moments {
  background: linear-gradient(180deg, var(--night) 0%, var(--deep) 100%);
  color: var(--ice);
}

.page-about .about-moments__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1rem;
}

.page-about .about-moment {
  padding: 1.5rem 1.3rem 1.6rem;
  background: rgba(23, 59, 102, 0.42);
  border: 1px solid rgba(216, 169, 78, 0.24);
  border-top: 2px solid var(--gold);
  border-radius: 2px;
  backdrop-filter: blur(6px);
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-moment:hover {
  border-color: rgba(216, 169, 78, 0.62);
  box-shadow: var(--shadow-lift);
}

.page-about .about-moment__time {
  margin: 0;
  font-size: 0.76rem;
  letter-spacing: 0.1em;
  color: var(--gold-soft);
}

.page-about .about-moment h3 {
  margin: 0.7rem 0 0;
  font-size: 1.08rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--ice);
}

.page-about .about-moment p {
  margin: 0.75rem 0 0;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--about-mute);
}

/* ---------- 服务原则 ---------- */
.page-about .about-principles {
  background: var(--ice);
  color: var(--ink);
}

.page-about .about-principles__grid {
  display: grid;
  gap: 1rem;
}

.page-about .about-rule {
  padding: 1.6rem 1.35rem 1.5rem;
  background: #ffffff;
  border: 1px solid rgba(42, 74, 107, 0.16);
  border-radius: 3px;
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-rule:hover,
.page-about .about-rule:focus-within {
  transform: translateY(-4px);
  border-color: var(--gold);
  box-shadow: var(--shadow-lift);
}

.page-about .about-rule__no {
  display: block;
  font-size: 0.76rem;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .about-rule h3 {
  margin: 0.6rem 0 0;
  font-size: 1.12rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--deep);
}

.page-about .about-rule__lead {
  margin: 0.7rem 0 0;
  font-size: 0.92rem;
  line-height: 1.8;
  color: rgba(20, 36, 59, 0.78);
}

.page-about .about-rule__how {
  margin-top: 0.9rem;
  padding-top: 0.9rem;
  border-top: 1px dashed rgba(42, 74, 107, 0.26);
}

.page-about .about-rule__how .tag {
  display: inline-block;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--ember);
  border: 1px solid rgba(228, 87, 46, 0.4);
  border-radius: 999px;
  padding: 0.15rem 0.6rem;
}

.page-about .about-rule__how p {
  margin: 0.65rem 0 0;
  font-size: 0.88rem;
  line-height: 1.78;
  color: rgba(20, 36, 59, 0.7);
}

@media (min-width: 800px) and (hover: hover) {
  .page-about .about-rule__how {
    margin-top: 0;
    padding-top: 0;
    border-top-color: transparent;
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height var(--dur) var(--ease), opacity var(--dur) var(--ease),
      margin-top var(--dur) var(--ease), padding-top var(--dur) var(--ease);
  }

  .page-about .about-rule:hover .about-rule__how,
  .page-about .about-rule:focus-within .about-rule__how {
    max-height: 14rem;
    opacity: 1;
    margin-top: 0.9rem;
    padding-top: 0.9rem;
    border-top-color: rgba(42, 74, 107, 0.26);
  }
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  background: var(--ice);
  color: var(--ink);
}

.page-about .about-team__grid {
  display: grid;
  gap: clamp(1.75rem, 5vw, 3rem);
  align-items: start;
}

.page-about .about-team__text h2 {
  margin: 0.5rem 0 0;
  font-size: clamp(1.6rem, 3.6vw, 2.35rem);
  font-weight: 600;
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--deep);
}

.page-about .about-team__text p {
  margin: 1rem 0 0;
  font-size: 0.95rem;
  line-height: 1.85;
  color: rgba(20, 36, 59, 0.82);
}

.page-about .about-team__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.1rem 1.1rem;
  margin: 1.85rem 0 0;
}

.page-about .about-stat {
  padding-top: 0.8rem;
  border-top: 1px solid rgba(42, 74, 107, 0.2);
}

.page-about .about-stat dt {
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  color: rgba(20, 36, 59, 0.6);
}

.page-about .about-stat dd {
  margin: 0.35rem 0 0;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3vw, 1.95rem);
  font-weight: 600;
  line-height: 1.1;
  color: var(--deep);
}

.page-about .about-stat dd span {
  margin-left: 0.25rem;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 400;
  color: rgba(20, 36, 59, 0.58);
}

.page-about .about-team__figure {
  margin: 0;
}

.page-about .about-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border-radius: 2px;
  border: 1px solid rgba(42, 74, 107, 0.16);
}

.page-about .about-team__figure figcaption {
  margin-top: 0.7rem;
  font-size: 0.78rem;
  letter-spacing: 0.03em;
  color: rgba(20, 36, 59, 0.58);
}

/* ---------- 发展历程 ---------- */
.page-about .about-timeline {
  background: linear-gradient(180deg, var(--deep) 0%, var(--night) 100%);
  color: var(--ice);
}

.page-about .about-stages {
  display: grid;
  gap: clamp(1.75rem, 4vw, 2.5rem);
}

.page-about .about-stages__index-label {
  margin: 0;
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .about-stages__index .tablist {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.85rem;
}

.page-about .about-stages__index .tab {
  appearance: none;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  padding: 0.5rem 0.85rem;
  background: transparent;
  color: rgba(246, 248, 251, 0.7);
  border: 1px solid rgba(216, 169, 78, 0.28);
  border-radius: 999px;
  cursor: pointer;
  text-align: left;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-stages__index .tab:hover {
  color: var(--gold-soft);
  border-color: var(--gold);
}

.page-about .about-stages__index .tab[aria-selected="true"] {
  background: rgba(216, 169, 78, 0.16);
  border-color: var(--gold);
  color: var(--gold-soft);
}

.page-about .about-stages__panels {
  position: relative;
  padding-left: 1.5rem;
  border-left: 1px solid rgba(216, 169, 78, 0.28);
  display: grid;
  gap: 1.6rem;
}

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

.page-about .about-stage::before {
  content: "";
  position: absolute;
  left: calc(-1.5rem - 5px);
  top: 0.45rem;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(216, 169, 78, 0.16);
}

.page-about .about-stage h3 {
  margin: 0;
  font-size: 1.12rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--gold-soft);
}

.page-about .about-stage p {
  margin: 0.6rem 0 0;
  font-size: 0.92rem;
  line-height: 1.85;
  color: var(--about-mute);
}

.page-about .about-timeline__figure {
  margin: clamp(2rem, 5vw, 3rem) 0 0;
}

.page-about .about-timeline__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
  border-radius: 2px;
  border: 1px solid rgba(216, 169, 78, 0.24);
}

.page-about .about-timeline__figure figcaption {
  margin-top: 0.7rem;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: rgba(246, 248, 251, 0.54);
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  background: var(--ice);
  color: var(--ink);
}

.page-about .about-partners__grid {
  display: grid;
  gap: clamp(1.75rem, 5vw, 3rem);
  align-items: start;
}

.page-about .about-partners__intro h2 {
  margin: 0.5rem 0 0;
  font-size: clamp(1.6rem, 3.6vw, 2.35rem);
  font-weight: 600;
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--deep);
}

.page-about .about-partners__intro p {
  margin: 1rem 0 0;
  font-size: 0.95rem;
  line-height: 1.85;
  color: rgba(20, 36, 59, 0.8);
}

.page-about .about-partners__list {
  border-bottom: 1px solid rgba(42, 74, 107, 0.2);
}

.page-about .about-fold {
  border-top: 1px solid rgba(42, 74, 107, 0.2);
  padding: 1rem 0;
}

.page-about .about-fold summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  list-style: none;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 600;
  color: var(--deep);
}

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

.page-about .about-fold summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.15rem;
  line-height: 1;
  color: var(--gold);
  transition: transform var(--dur) var(--ease);
}

.page-about .about-fold[open] summary::after {
  transform: rotate(45deg);
}

.page-about .about-fold p {
  margin: 0.8rem 0 0.2rem;
  font-size: 0.92rem;
  line-height: 1.82;
  color: rgba(20, 36, 59, 0.76);
}

/* ---------- 接下来 ---------- */
.page-about .about-next {
  background: linear-gradient(150deg, var(--deep) 0%, var(--night) 100%);
  color: var(--ice);
  padding-block: clamp(3rem, 7vw, 5.5rem) clamp(2rem, 5vw, 3.25rem);
}

.page-about .about-next__grid {
  display: grid;
  gap: clamp(1.75rem, 5vw, 3rem);
  align-items: start;
}

.page-about .about-next__intro h2 {
  margin: 0.5rem 0 0;
  font-size: clamp(1.65rem, 3.8vw, 2.5rem);
  font-weight: 600;
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--ice);
}

.page-about .about-next__intro p {
  margin: 1rem 0 0;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--about-mute);
}

.page-about .about-next__links {
  display: grid;
  gap: 0.75rem;
}

.page-about .about-next__link {
  display: block;
  padding: 1.05rem 1.15rem;
  border: 1px solid rgba(216, 169, 78, 0.26);
  border-radius: 2px;
  text-decoration: none;
  color: var(--ice);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease),
    background var(--dur) var(--ease);
}

.page-about .about-next__link:hover {
  transform: translateY(-2px);
  border-color: var(--gold);
  background: rgba(216, 169, 78, 0.08);
}

.page-about .about-next__link strong {
  display: block;
  font-size: 1rem;
  font-weight: 600;
}

.page-about .about-next__link span {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.82rem;
  line-height: 1.6;
  color: rgba(246, 248, 251, 0.64);
}

.page-about .about-next__bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.6rem;
  align-items: center;
  margin-top: clamp(2rem, 5vw, 3rem);
  padding-top: 1.25rem;
  border-top: 1px solid rgba(216, 169, 78, 0.24);
}

.page-about .about-next__bar a {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--gold-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(216, 169, 78, 0.42);
  padding-bottom: 2px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-next__bar a:hover {
  color: var(--ice);
  border-bottom-color: var(--gold);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-next__links {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 780px) {
  .page-about .about-moments__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.25rem;
    padding-bottom: 2.25rem;
    align-items: start;
  }

  .page-about .about-moment:nth-child(2) {
    transform: translateY(2.25rem);
  }

  .page-about .about-principles__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.15rem;
  }

  .page-about .about-team__stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.35rem;
  }
}

@media (min-width: 860px) {
  .page-about .about-origin__grid {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: clamp(2rem, 5vw, 4rem);
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.8fr);
    gap: clamp(2rem, 4vw, 3.5rem);
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.88fr);
    gap: clamp(2rem, 5vw, 4rem);
  }

  .page-about .about-stages {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: clamp(2rem, 5vw, 3.5rem);
  }

  .page-about .about-stages__index {
    position: sticky;
    top: 1.5rem;
    align-self: start;
  }

  .page-about .about-stages__index .tablist {
    flex-direction: column;
    flex-wrap: nowrap;
    align-items: stretch;
  }

  .page-about .about-partners__grid {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    gap: clamp(2rem, 5vw, 4rem);
  }

  .page-about .about-next__grid {
    grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
    gap: clamp(2rem, 5vw, 4rem);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-moment,
  .page-about .about-rule,
  .page-about .about-rule__how,
  .page-about .about-next__link,
  .page-about .about-fold summary::after {
    transition-duration: 0.01ms;
  }

  .page-about .about-rule:hover,
  .page-about .about-rule:focus-within,
  .page-about .about-next__link:hover,
  .page-about .about-moment:nth-child(2) {
    transform: none;
  }
}