.page-about {
  --about-rail: 244px;
  --about-gap: clamp(28px, 4vw, 68px);
  padding-bottom: clamp(48px, 8vw, 112px);
}

.page-about .sf-crumbs {
  margin: clamp(18px, 3vw, 32px) 0 clamp(20px, 3vw, 34px);
}

.page-about .about-shell {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
  align-items: start;
}

/* ---------- 品牌档案栏 ---------- */
.page-about .about-dossier {
  background: var(--ink-900);
  border: var(--bd) solid var(--ink-700);
  box-shadow: var(--sh-hard);
  padding: 20px;
}

.page-about .about-dossier__title {
  margin: 0 0 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--ink-700);
  font-family: var(--f-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--volt-400);
}

.page-about .about-dossier__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 12px;
  margin: 0;
}

.page-about .about-dossier__row dt {
  margin: 0 0 5px;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mist-400);
}

.page-about .about-dossier__row dd {
  margin: 0;
  font-family: var(--f-cond);
  font-size: 21px;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--mist-100);
}

.page-about .about-dossier__note {
  margin: 20px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--ink-700);
  font-size: 13px;
  line-height: 1.65;
  color: var(--mist-400);
}

/* ---------- 首屏导语 ---------- */
.page-about .about-hero {
  padding-bottom: clamp(30px, 4vw, 48px);
  border-bottom: var(--bd) solid var(--ink-700);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 18px;
  font-family: var(--f-mono);
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--flare-500);
}

.page-about .about-hero h1 {
  margin: 0 0 24px;
  font-family: var(--f-cond);
  font-size: clamp(36px, 6vw, 66px);
  font-weight: 800;
  line-height: 1.04;
  letter-spacing: -0.01em;
  color: var(--mist-100);
  max-width: 18ch;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 60ch;
  font-family: var(--f-serif);
  font-size: clamp(16px, 1.5vw, 20px);
  line-height: 1.85;
  color: var(--mist-100);
}

/* ---------- 通用章节 ---------- */
.page-about .about-sec {
  padding: clamp(36px, 5vw, 64px) 0;
  border-bottom: 1px solid var(--ink-700);
}

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

.page-about .about-kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 14px;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--volt-400);
}

.page-about .about-kicker::before {
  content: "";
  flex: 0 0 auto;
  width: 26px;
  height: 2px;
  background: var(--volt-400);
}

.page-about .about-h2 {
  margin: 0 0 18px;
  font-family: var(--f-cond);
  font-size: clamp(27px, 3.6vw, 44px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--mist-100);
  max-width: 22ch;
}

.page-about .about-p {
  margin: 0 0 16px;
  max-width: 68ch;
  font-size: 17px;
  line-height: 1.78;
  color: var(--mist-100);
}

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

.page-about .about-note {
  margin: 24px 0 0;
  padding-left: 18px;
  border-left: 2px solid var(--flare-500);
  max-width: 62ch;
  font-family: var(--f-serif);
  font-size: 16px;
  line-height: 1.9;
  color: var(--mist-400);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0;
  border: var(--bd) solid var(--ink-700);
  box-shadow: var(--sh-hard);
  background: var(--ink-800);
  overflow: hidden;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.92) contrast(1.04);
}

.page-about .about-figure--wide {
  margin-top: clamp(26px, 4vw, 42px);
}

/* ---------- 起点分栏 ---------- */
.page-about .about-sec__split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  margin: 28px 0 0;
  padding: 0 0 0 60px;
  list-style: none;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 19px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--volt-400), rgba(22, 224, 198, 0.1));
}

.page-about .about-timeline__item {
  position: relative;
  padding-bottom: 32px;
}

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

.page-about .about-timeline__node {
  position: absolute;
  left: -60px;
  top: 0;
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  background: var(--ink-800);
  border: var(--bd) solid var(--flare-500);
  color: var(--flare-500);
  font-family: var(--f-mono);
  font-size: 13px;
  font-weight: 700;
}

.page-about .about-timeline__year {
  margin: 0 0 6px;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--flare-300);
}

.page-about .about-timeline__title {
  margin: 0 0 10px;
  font-family: var(--f-cond);
  font-size: clamp(22px, 2.4vw, 27px);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--mist-100);
}

.page-about .about-timeline__desc {
  margin: 0;
  max-width: 58ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--mist-400);
}

/* ---------- 团队分段切换 ---------- */
.page-about .about-roles {
  margin: 26px 0 0;
}

.page-about .about-roles__nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-bottom: 18px;
  margin-bottom: 22px;
  border-bottom: var(--bd) solid var(--ink-700);
}

.page-about .about-roles__nav .sf-tab {
  min-height: 44px;
  padding: 10px 16px;
  background: var(--ink-800);
  border: var(--bd) solid var(--ink-700);
  color: var(--mist-400);
  font-family: var(--f-cond);
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.02em;
  cursor: pointer;
}

.page-about .about-roles__nav .sf-tab[aria-selected="true"] {
  background: var(--ink-800);
  border-color: var(--flare-500);
  color: var(--mist-100);
}

.page-about .about-roles__panel {
  background: var(--ink-900);
  border: var(--bd) solid var(--ink-700);
  border-left: 3px solid var(--flare-500);
  box-shadow: var(--sh-soft);
  padding: clamp(20px, 3vw, 30px);
}

.page-about .about-roles__panel:focus-visible {
  outline: 2px solid var(--flare-500);
  outline-offset: 3px;
}

.page-about .about-roles__count {
  margin: 0 0 10px;
  font-family: var(--f-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--mist-400);
}

.page-about .about-roles__count span {
  font-family: var(--f-cond);
  font-size: 46px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--volt-400);
  margin-right: 6px;
  vertical-align: -4px;
}

.page-about .about-roles__title {
  margin: 0 0 12px;
  font-family: var(--f-cond);
  font-size: 24px;
  font-weight: 800;
  line-height: 1.2;
  color: var(--mist-100);
}

.page-about .about-roles__desc {
  margin: 0;
  max-width: 64ch;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist-100);
}

/* ---------- 覆盖 ---------- */
.page-about .about-reach {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 26px 0 26px;
}

.page-about .about-reach__block {
  position: relative;
  padding: 22px 24px 20px;
  background: var(--ink-800);
  border: var(--bd) solid var(--ink-700);
  border-top: 3px solid var(--flare-500);
  box-shadow: var(--sh-hard);
}

.page-about .about-reach__block--volt {
  border-top-color: var(--volt-400);
}

.page-about .about-reach__num {
  margin: 0;
  font-family: var(--f-mono);
  font-size: clamp(54px, 9vw, 96px);
  font-weight: 700;
  line-height: 0.92;
  letter-spacing: -0.04em;
  color: var(--flare-500);
}

.page-about .about-reach__block--volt .about-reach__num {
  color: var(--volt-400);
}

.page-about .about-reach__label {
  margin: 12px 0 0;
  font-family: var(--f-cond);
  font-size: 18px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--mist-400);
}

/* ---------- 十二项适配 ---------- */
.page-about .about-sec--fit {
  position: relative;
}

.page-about .about-fit {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin: 28px 0 0;
}

.page-about .about-fit__col {
  background: var(--ink-900);
  border: var(--bd) solid var(--ink-700);
  padding: 22px 22px 14px;
}

.page-about .about-fit__head {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin: 0 0 14px;
  font-family: var(--f-cond);
  font-size: 19px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--mist-100);
}

.page-about .about-fit__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-fit__list li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 11px 0;
  border-bottom: 1px solid var(--ink-700);
  font-size: 16px;
  line-height: 1.5;
  color: var(--mist-100);
}

.page-about .about-fit__list li:last-child {
  border-bottom: 0;
}

.page-about .about-fit__idx {
  flex: 0 0 auto;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--volt-400);
}

/* ---------- 合作伙伴 ---------- */
.page-about .about-allies {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin: 26px 0;
  padding: 0;
  list-style: none;
}

.page-about .about-allies__item {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 18px 20px;
  background: var(--ink-800);
  border: var(--bd) solid var(--ink-700);
}

.page-about .about-allies__num {
  flex: 0 0 auto;
  min-width: 3.4ch;
  font-family: var(--f-mono);
  font-size: clamp(30px, 4vw, 42px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--amber-500);
}

.page-about .about-allies__label {
  font-size: 16px;
  line-height: 1.5;
  color: var(--mist-100);
}

/* ---------- 三种合作方式 ---------- */
.page-about .about-start {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-start__item {
  display: flex;
  flex-direction: column;
  padding: 22px 22px 24px;
  background: var(--ink-900);
  border: var(--bd) solid var(--ink-700);
  border-bottom: 3px solid var(--volt-700);
}

.page-about .about-start__idx {
  margin: 0 0 12px;
  font-family: var(--f-mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--volt-400);
}

.page-about .about-start__title {
  margin: 0 0 10px;
  font-family: var(--f-cond);
  font-size: 23px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--mist-100);
}

.page-about .about-start__desc {
  margin: 0 0 18px;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--mist-400);
}

.page-about .about-start__item .sf-link {
  margin-top: auto;
  align-self: flex-start;
}

.page-about .about-cta {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 18px;
  margin-top: clamp(26px, 4vw, 40px);
  padding: clamp(22px, 3vw, 32px);
  background: var(--ink-800);
  border: var(--bd) solid var(--ink-700);
  box-shadow: var(--sh-hard);
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 52ch;
  font-family: var(--f-serif);
  font-size: 17px;
  line-height: 1.85;
  color: var(--mist-100);
}

/* ---------- 窄屏优先：断点 ---------- */
@media (min-width: 640px) {
  .page-about .about-reach {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

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

  .page-about .about-allies__item {
    flex-direction: column;
    gap: 10px;
  }

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

  .page-about .about-cta {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

@media (min-width: 860px) {
  .page-about .about-sec__split {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    align-items: start;
    gap: clamp(28px, 4vw, 52px);
  }

  .page-about .about-fit {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
  }

  .page-about .about-dossier {
    position: sticky;
    top: 96px;
    padding: 24px;
  }

  .page-about .about-dossier__list {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .page-about .about-dossier__row dd {
    font-size: 22px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-figure img {
    filter: none;
  }
}
</main>