.page-about {
  --about-rail: 236px;
  --about-line: var(--sd-gold-line);
  background: var(--sd-ink);
  color: var(--sd-cream);
}

.page-about a {
  color: var(--sd-gold-soft);
  text-decoration-color: var(--sd-gold-line);
  text-underline-offset: 3px;
}

.page-about a:hover,
.page-about a:focus-visible {
  color: var(--sd-cream);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(18px, 3vw, 30px) var(--sd-pad) clamp(34px, 6vw, 72px);
  background:
    radial-gradient(circle at 84% 12%, rgba(201, 162, 39, 0.20), transparent 48%),
    linear-gradient(163deg, var(--sd-ink-2) 0%, var(--sd-ink) 64%);
  border-bottom: 1px solid var(--sd-gold-line-2);
}

.page-about .about-hero__ring {
  position: absolute;
  top: -16vw;
  right: -16vw;
  width: min(60vw, 620px);
  aspect-ratio: 1;
  border-radius: 50%;
  border: 1px solid var(--sd-gold-line);
  background: radial-gradient(circle at 50% 50%, rgba(201, 162, 39, 0.10), transparent 64%);
  pointer-events: none;
}

.page-about .about-hero__ring::before {
  content: "";
  position: absolute;
  inset: 15%;
  border-radius: 50%;
  border: 1px dashed var(--sd-gold-line-2);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  max-width: var(--sd-shell);
  margin: 0 auto;
}

.page-about .sd-crumbs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin: 0 0 clamp(20px, 3vw, 34px);
  padding: 0;
  font-family: var(--sd-font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--sd-cream-faint);
}

.page-about .sd-crumbs__list li + li::before {
  content: "/";
  margin-right: 10px;
  color: var(--sd-gold-line);
}

.page-about .sd-crumbs__list a {
  color: var(--sd-cream-dim);
  text-decoration: none;
}

.page-about .sd-crumbs__list a:hover {
  color: var(--sd-gold-soft);
}

.page-about .sd-crumbs__list [aria-current="page"] {
  color: var(--sd-gold-soft);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 clamp(14px, 2vw, 22px);
  font-family: var(--sd-font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--sd-gold);
}

.page-about .about-hero__title {
  margin: 0 0 clamp(18px, 2.4vw, 30px);
  font-family: var(--sd-font-display);
  font-weight: 900;
  font-size: clamp(42px, 9vw, 112px);
  line-height: 0.96;
  letter-spacing: -0.045em;
  color: var(--sd-cream);
}

.page-about .about-hero__title-line {
  display: block;
  color: var(--sd-gold-soft);
}

.page-about .about-hero__lede {
  max-width: 62ch;
  margin: 0 0 clamp(22px, 3vw, 34px);
  font-size: clamp(16px, 1.7vw, 18px);
  line-height: 1.78;
  color: var(--sd-cream-dim);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(28px, 4.4vw, 48px) 0 0;
  padding: 0;
  list-style: none;
  border: 1px solid var(--sd-gold-line-2);
  border-radius: var(--sd-radius-m);
  background: var(--sd-gold-line-2);
  overflow: hidden;
}

.page-about .about-facts__item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px clamp(12px, 2vw, 20px);
  background: rgba(11, 46, 39, 0.88);
}

.page-about .about-facts__num {
  font-family: var(--sd-font-mono);
  font-size: clamp(20px, 2.6vw, 30px);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--sd-gold-soft);
}

.page-about .about-facts__label {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--sd-cream-faint);
}

/* ---------- 主体框架 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 44px);
  max-width: var(--sd-shell);
  margin: 0 auto;
  padding: clamp(34px, 6vw, 80px) var(--sd-pad) clamp(48px, 8vw, 96px);
}

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

.page-about .about-rail__label {
  margin: 0 0 10px;
  font-family: var(--sd-font-mono);
  font-size: 11px;
  letter-spacing: 0.24em;
  color: var(--sd-gold);
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0 0 14px;
  padding: 2px 0 8px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail__item {
  flex: 0 0 auto;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--sd-gold-line-2);
  border-radius: 999px;
  background: rgba(18, 69, 58, 0.55);
  font-size: 13px;
  line-height: 1.2;
  color: var(--sd-cream-dim);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s var(--sd-ease), border-color 0.2s var(--sd-ease), background 0.2s var(--sd-ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--sd-cream);
  border-color: var(--sd-gold);
  background: var(--sd-ink-3);
}

.page-about .about-rail__num {
  font-family: var(--sd-font-mono);
  font-size: 11px;
  color: var(--sd-gold);
}

.page-about .about-rail__cta {
  display: inline-block;
  font-family: var(--sd-font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--sd-red-soft);
  text-decoration: none;
  border-bottom: 1px solid var(--sd-red);
  padding-bottom: 2px;
}

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

/* ---------- 章节 ---------- */
.page-about .about-sec {
  scroll-margin-top: calc(var(--sd-head-h) + 24px);
}

.page-about .about-sec + .about-sec {
  margin-top: clamp(44px, 6.5vw, 84px);
  padding-top: clamp(28px, 4vw, 48px);
  border-top: 1px solid var(--sd-gold-line-2);
}

.page-about .about-sec__head {
  display: flex;
  align-items: flex-start;
  gap: clamp(12px, 2vw, 20px);
  margin-bottom: clamp(18px, 2.6vw, 28px);
}

.page-about .about-sec__num {
  flex: 0 0 auto;
  margin-top: 5px;
  padding: 3px 8px;
  border: 1px solid var(--sd-gold-line);
  border-radius: var(--sd-radius-s);
  font-family: var(--sd-font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--sd-gold);
}

.page-about .sd-h2 {
  margin: 0;
  font-family: var(--sd-font-display);
  font-weight: 900;
  font-size: clamp(25px, 3.5vw, 42px);
  line-height: 1.16;
  letter-spacing: -0.025em;
  color: var(--sd-cream);
}

.page-about .sd-lede {
  margin: 0 0 16px;
  font-size: clamp(17px, 1.9vw, 20px);
  line-height: 1.7;
  color: var(--sd-cream);
}

.page-about .about-split__text p,
.page-about .about-lead,
.page-about .about-principles__item p,
.page-about .about-scene p,
.page-about .about-team__item p,
.page-about .about-eco__body p,
.page-about .about-timeline__body p,
.page-about .about-faq__a p {
  margin: 0 0 14px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--sd-cream-dim);
}

.page-about .about-split__text p:last-child,
.page-about .about-eco__body p:last-child,
.page-about .about-faq__a p:last-child {
  margin-bottom: 0;
}

.page-about .about-lead {
  max-width: 66ch;
  margin-bottom: clamp(18px, 2.6vw, 26px);
  font-size: 16px;
}

/* ---------- 图文错位 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 36px);
  align-items: start;
}

.page-about .about-split--tight {
  margin-top: clamp(24px, 3.6vw, 40px);
}

.page-about .about-figure {
  position: relative;
  margin: 0;
  border: 1px solid var(--sd-gold-line-2);
  border-radius: var(--sd-radius-m);
  border-top-right-radius: 0;
  overflow: hidden;
  background: var(--sd-ink-2);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-figure__cap {
  margin: 0;
  padding: 10px clamp(12px, 2vw, 16px) 12px;
  border-top: 1px solid var(--sd-gold-line-2);
  font-family: var(--sd-font-mono);
  font-size: 11.5px;
  line-height: 1.7;
  color: var(--sd-cream-faint);
}

.page-about .about-figure--wide {
  border-top-right-radius: var(--sd-radius-m);
  border-radius: var(--sd-radius-m);
}

/* ---------- 原则 ---------- */
.page-about .about-quote {
  margin: 0 0 clamp(16px, 2.4vw, 26px);
  padding: 0 0 0 clamp(14px, 3vw, 26px);
  border-left: 3px solid var(--sd-gold);
  font-family: var(--sd-font-display);
  font-size: clamp(22px, 3.4vw, 36px);
  font-weight: 900;
  line-height: 1.3;
  letter-spacing: -0.02em;
  color: var(--sd-cream);
}

.page-about .about-principles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(12px, 2vw, 18px);
  margin: 0 0 clamp(26px, 4vw, 44px);
  padding: 0;
  list-style: none;
}

.page-about .about-principles__item {
  position: relative;
  padding: clamp(18px, 2.4vw, 26px);
  border: 1px solid var(--sd-gold-line-2);
  border-radius: var(--sd-radius-m);
  border-top-right-radius: 0;
  background: linear-gradient(170deg, rgba(27, 91, 75, 0.46), rgba(11, 46, 39, 0.72));
}

.page-about .about-principles__item::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 26px;
  height: 26px;
  background: linear-gradient(225deg, var(--sd-gold) 50%, transparent 50%);
  opacity: 0.72;
}

.page-about .about-principles__num {
  display: block;
  margin-bottom: 8px;
  font-family: var(--sd-font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--sd-gold);
}

.page-about .about-principles__title {
  margin: 0 0 8px;
  font-family: var(--sd-font-display);
  font-size: clamp(18px, 2vw, 21px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--sd-cream);
}

.page-about .about-sub {
  margin: 0 0 14px;
  font-family: var(--sd-font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--sd-teal);
}

.page-about .about-scenes {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 2.4vw, 22px);
}

.page-about .about-scene {
  padding-left: clamp(12px, 2vw, 18px);
  border-left: 2px solid var(--sd-gold-line);
}

.page-about .about-scene__title {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--sd-gold-soft);
}

.page-about .about-scene p {
  margin: 0;
  font-size: 14.5px;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 1px;
  list-style: none;
  border-radius: var(--sd-radius-m);
  background: var(--sd-gold-line-2);
}

.page-about .about-team__item {
  padding: clamp(16px, 2.4vw, 24px);
  background: var(--sd-ink-2);
}

.page-about .about-team__item:first-child {
  border-top-left-radius: var(--sd-radius-m);
  border-top-right-radius: var(--sd-radius-m);
}

.page-about .about-team__item:last-child {
  border-bottom-left-radius: var(--sd-radius-m);
  border-bottom-right-radius: var(--sd-radius-m);
}

.page-about .about-team__num {
  display: block;
  font-family: var(--sd-font-mono);
  font-size: clamp(30px, 4.4vw, 46px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--sd-gold-soft);
}

.page-about .about-team__role {
  margin: 8px 0 8px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--sd-cream);
}

.page-about .about-team__item p {
  margin: 0;
  font-size: 14.5px;
}

/* ---------- 合作生态 ---------- */
.page-about .about-eco {
  padding: clamp(16px, 2.6vw, 28px);
  border: 1px solid var(--sd-gold-line-2);
  border-radius: var(--sd-radius-l);
  background: linear-gradient(140deg, var(--sd-ink-2), var(--sd-ink) 72%);
}

.page-about .about-eco__body {
  margin-top: clamp(18px, 2.6vw, 26px);
}

.page-about .about-eco__list {
  margin: 0 0 clamp(16px, 2.4vw, 24px);
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--sd-gold-line-2);
  border-radius: var(--sd-radius-s);
  overflow: hidden;
}

.page-about .about-eco__list li {
  padding: 14px clamp(12px, 2vw, 18px);
  background: rgba(11, 46, 39, 0.9);
}

.page-about .about-eco__k {
  display: block;
  margin-bottom: 4px;
  font-family: var(--sd-font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--sd-gold);
}

.page-about .about-eco__v {
  display: block;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--sd-cream-dim);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--sd-gold), rgba(201, 162, 39, 0.08));
}

.page-about .about-timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding-bottom: clamp(22px, 3.4vw, 34px);
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 14px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 2px solid var(--sd-gold);
  background: var(--sd-ink);
}

.page-about .about-timeline__item:first-child::before {
  border-color: var(--sd-red);
  box-shadow: 0 0 0 4px rgba(201, 74, 50, 0.18);
}

.page-about .about-timeline__year {
  font-family: var(--sd-font-mono);
  font-size: clamp(24px, 3.4vw, 40px);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--sd-gold-soft);
}

.page-about .about-timeline__title {
  margin: 0 0 6px;
  font-size: 16.5px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--sd-cream);
}

.page-about .about-timeline__body p {
  margin: 0;
  font-size: 14.5px;
}

/* ---------- 问答 ---------- */
.page-about .about-faq {
  border-top: 1px solid var(--sd-gold-line-2);
}

.page-about .about-faq__item {
  border-bottom: 1px solid var(--sd-gold-line-2);
}

.page-about .about-faq__q {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 0;
  cursor: pointer;
  list-style: none;
  font-size: clamp(15.5px, 1.8vw, 17.5px);
  font-weight: 700;
  line-height: 1.55;
  color: var(--sd-cream);
  transition: color 0.2s var(--sd-ease);
}

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

.page-about .about-faq__q::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--sd-font-mono);
  font-size: 20px;
  line-height: 1.1;
  color: var(--sd-gold);
}

.page-about .about-faq__item[open] .about-faq__q::after {
  content: "\2212";
}

.page-about .about-faq__q:hover {
  color: var(--sd-gold-soft);
}

.page-about .about-faq__a {
  padding: 0 0 18px;
}

.page-about .about-faq__a p {
  max-width: 68ch;
  font-size: 15px;
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  margin-top: clamp(40px, 6vw, 72px);
  padding-top: clamp(24px, 3.6vw, 36px);
  border-top: 1px solid var(--sd-gold-line);
}

.page-about .about-next__title {
  margin: 0 0 clamp(14px, 2vw, 20px);
  font-family: var(--sd-font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--sd-gold);
}

.page-about .about-next__list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 1px;
  list-style: none;
  border-radius: var(--sd-radius-m);
  background: var(--sd-gold-line-2);
}

.page-about .about-next__link {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: clamp(14px, 2vw, 20px);
  background: var(--sd-ink-2);
  text-decoration: none;
  transition: background 0.2s var(--sd-ease), transform 0.2s var(--sd-ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: var(--sd-ink-3);
  transform: translateY(-2px);
}

.page-about .about-next__k {
  font-size: 15px;
  font-weight: 700;
  color: var(--sd-cream);
}

.page-about .about-next__d {
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--sd-cream-faint);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

  .page-about .about-team__item:first-child {
    border-radius: var(--sd-radius-m) 0 0 var(--sd-radius-m);
  }

  .page-about .about-team__item:last-child {
    border-radius: 0 var(--sd-radius-m) var(--sd-radius-m) 0;
  }

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

  .page-about .about-timeline__item {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: clamp(12px, 2.4vw, 30px);
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(30px, 4vw, 60px);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--sd-head-h) + 28px);
    align-self: start;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-rail__item {
    flex: none;
  }

  .page-about .about-rail__link {
    width: 100%;
    padding: 9px 0 9px 14px;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    background: none;
    white-space: normal;
    font-size: 13.5px;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--sd-gold);
    background: rgba(27, 91, 75, 0.28);
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  }

  .page-about .about-split--flip {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
  }

  .page-about .about-split--flip .about-figure {
    order: -1;
  }

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

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

  .page-about .about-timeline__item {
    grid-template-columns: 156px minmax(0, 1fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .about-next__link,
  .page-about .about-faq__q {
    transition: none;
  }

  .page-about .about-next__link:hover,
  .page-about .about-next__link:focus-visible {
    transform: none;
  }
}