.page-about {
  --about-rule: 2px solid var(--ink);
  --about-pad: clamp(28px, 5vw, 56px);
  background: var(--bone);
  color: var(--ink);
  font-family: var(--font-body);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  background: var(--ice-deep);
  color: var(--bone);
  padding: clamp(20px, 3vw, 34px) 0 clamp(44px, 7vw, 88px);
  overflow: hidden;
  isolation: isolate;
}

.page-about .about-hero__glyph {
  position: absolute;
  right: -10%;
  bottom: -14%;
  width: min(760px, 82vw);
  height: auto;
  color: var(--glacier);
  opacity: .7;
  z-index: 0;
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  max-width: var(--wrap-wide);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.page-about .about-hero__crumb {
  margin: 0 0 clamp(26px, 5vw, 52px);
}

.page-about .about-hero__crumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--mist);
}

.page-about .about-hero__crumb li {
  display: flex;
  align-items: center;
  gap: 10px;
}

.page-about .about-hero__crumb li + li::before {
  content: "/";
  color: var(--glacier);
}

.page-about .about-hero__crumb a {
  color: var(--mist);
  text-decoration: none;
}

.page-about .about-hero__crumb a:hover,
.page-about .about-hero__crumb a:focus-visible {
  color: var(--bone);
  text-decoration: underline;
}

.page-about .about-hero__kicker {
  color: var(--ivory);
  margin: 0 0 14px;
}

.page-about .about-hero__title {
  display: flex;
  flex-direction: column;
  margin: 0 0 clamp(20px, 3vw, 32px);
  font-family: var(--font-display);
  font-size: clamp(34px, 7.6vw, 100px);
  line-height: .98;
  letter-spacing: -.02em;
}

.page-about .about-hero__thin {
  font-weight: 200;
  font-size: .52em;
  line-height: 1.2;
  letter-spacing: .02em;
  color: var(--mist);
  margin-bottom: .18em;
}

.page-about .about-hero__thick {
  font-weight: 900;
  color: var(--bone);
}

.page-about .about-hero__lede {
  max-width: 62ch;
  color: rgba(244, 241, 234, .86);
  margin: 0;
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: rgba(244, 241, 234, .24);
  border: 1px solid rgba(244, 241, 234, .24);
  list-style: none;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: 0;
  max-width: 780px;
}

.page-about .about-hero__facts li {
  background: var(--ice-deep);
  padding: 16px 18px;
}

.page-about .about-hero__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3.4vw, 34px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--ivory);
}

.page-about .about-hero__key {
  display: block;
  margin-top: 7px;
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--mist);
}

/* ---------- 主体外壳 ---------- */
.page-about .about-shell {
  max-width: var(--wrap-wide);
  margin: 0 auto;
  padding: clamp(30px, 5vw, 56px) var(--gutter) clamp(48px, 7vw, 96px);
}

/* ---------- 章节索引 ---------- */
.page-about .about-toc {
  border-top: var(--about-rule);
  padding-top: 14px;
  margin-bottom: clamp(30px, 5vw, 48px);
}

.page-about .about-toc__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .24em;
  color: var(--ink-soft);
  margin: 0 0 12px;
}

.page-about .about-toc ol {
  display: flex;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-toc li {
  flex: none;
}

.page-about .about-toc a {
  display: block;
  padding: 8px 12px;
  border: 1px solid transparent;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--ink-soft);
  text-decoration: none;
  white-space: nowrap;
  transition: color .18s var(--ease), background-color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .about-toc a:hover,
.page-about .about-toc a:focus-visible {
  color: var(--ink);
  border-color: var(--ink);
}

.page-about .about-toc a[aria-current="true"],
.page-about .about-toc a.is-active {
  background: var(--ink);
  color: var(--bone);
  border-color: var(--ink);
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  position: relative;
  border-top: var(--about-rule);
  padding: clamp(28px, 4.5vw, 52px) 0 clamp(36px, 6vw, 72px);
}

.page-about .about-chapter::before {
  content: "";
  position: absolute;
  top: -2px;
  left: 0;
  width: clamp(52px, 9vw, 128px);
  height: 6px;
  background: var(--lava);
}

.page-about .about-chapter__head {
  margin-bottom: clamp(18px, 3vw, 30px);
}

.page-about .about-chapter__num {
  display: inline-block;
  margin: 0 0 10px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--lava);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--lava);
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(25px, 3.6vw, 44px);
  line-height: 1.14;
  letter-spacing: -.01em;
  color: var(--ink);
}

.page-about .about-chapter__body {
  display: grid;
  gap: clamp(20px, 3vw, 34px);
}

.page-about .about-chapter__body p {
  margin: 0;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.78;
  color: var(--ink-soft);
}

.page-about .about-chapter__lede {
  font-size: clamp(16px, 1.9vw, 19px) !important;
  line-height: 1.72 !important;
  color: var(--ink) !important;
}

.page-about .about-chapter__body a {
  color: var(--glacier);
  text-decoration: underline;
  text-underline-offset: 4px;
}

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

.page-about .about-split-text {
  display: grid;
  gap: clamp(16px, 2.4vw, 26px);
}

/* ---------- 媒体框 ---------- */
.page-about .about-figure {
  margin: 0;
}

.page-about .about-figure--narrow {
  max-width: 620px;
}

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

.page-about .about-figure__caption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: .04em;
  color: var(--ink-soft);
}

/* ---------- 团队分工矩阵 ---------- */
.page-about .team-grid {
  display: grid;
  gap: 2px;
  grid-template-columns: minmax(0, 1fr);
  list-style: none;
  margin: 0;
  padding: 0;
  background: var(--ink);
  border: var(--about-rule);
}

.page-about .team-grid__item {
  background: var(--cream);
  padding: clamp(18px, 2.6vw, 28px);
}

.page-about .team-grid__idx {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--lava);
}

.page-about .team-grid__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(18px, 2vw, 22px);
  line-height: 1.25;
  color: var(--ink);
}

.page-about .team-grid__desc {
  font-size: 15px !important;
  line-height: 1.72 !important;
  color: var(--ink-soft) !important;
}

/* ---------- 版本轨道 ---------- */
.page-about .version-rail {
  --rail-pad: clamp(20px, 3vw, 32px);
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--rail-pad);
  border-left: 3px solid var(--glacier);
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .version-rail__item {
  position: relative;
}

.page-about .version-rail__item::before {
  content: "";
  position: absolute;
  top: 7px;
  left: calc(-1 * var(--rail-pad) - 8px);
  width: 14px;
  height: 14px;
  background: var(--bone);
  border: 3px solid var(--glacier);
  box-sizing: border-box;
}

.page-about .version-rail__item:last-child::before {
  background: var(--lava);
  border-color: var(--lava);
}

.page-about .version-rail__tag {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--glacier);
}

.page-about .version-rail__item:last-child .version-rail__tag {
  color: var(--lava);
}

.page-about .version-rail__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(17px, 1.9vw, 21px);
  line-height: 1.3;
  color: var(--ink);
}

.page-about .version-rail__desc {
  font-size: 15px !important;
  line-height: 1.75 !important;
  color: var(--ink-soft) !important;
}

/* ---------- 覆盖网格 ---------- */
.page-about .coverage-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  list-style: none;
  margin: 0;
  padding: 0;
  background: var(--ink);
  border: var(--about-rule);
}

.page-about .coverage-grid li {
  background: var(--bone);
  padding: clamp(16px, 2.4vw, 26px);
}

.page-about .coverage-grid__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 4.4vw, 46px);
  font-weight: 700;
  line-height: 1;
  color: var(--ice-deep);
}

.page-about .coverage-grid__key {
  display: block;
  margin-top: 9px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-soft);
}

/* ---------- 合作清单 ---------- */
.page-about .partner-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: var(--about-rule);
}

.page-about .partner-list__item {
  padding: clamp(16px, 2.4vw, 24px) 0;
  border-bottom: var(--about-rule);
  display: grid;
  gap: 8px;
}

.page-about .partner-list__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(17px, 1.9vw, 21px);
  line-height: 1.3;
  color: var(--ink);
}

.page-about .about-quote {
  margin: 0;
  padding: clamp(20px, 3vw, 32px);
  background: var(--cream);
  border-left: 6px solid var(--lava);
}

.page-about .about-quote p {
  margin: 0 !important;
  font-size: clamp(16px, 1.9vw, 19px) !important;
  line-height: 1.68 !important;
  color: var(--ink) !important;
}

/* ---------- 信息条 ---------- */
.page-about .fact-list {
  margin: 0;
  border-top: var(--about-rule);
}

.page-about .fact-list__row {
  display: grid;
  gap: 6px;
  padding: 15px 0;
  border-bottom: var(--about-rule);
}

.page-about .fact-list__key {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--glacier);
}

.page-about .fact-list__val {
  margin: 0;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.7;
  color: var(--ink);
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-cta {
  background: var(--cream);
  border-top: var(--about-rule);
  padding: clamp(40px, 6vw, 80px) 0;
}

.page-about .about-cta__inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.page-about .about-cta__kicker {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .24em;
  color: var(--lava);
}

.page-about .about-cta__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 3.4vw, 40px);
  line-height: 1.16;
  color: var(--ink);
}

.page-about .about-cta__lede {
  max-width: 60ch;
  margin: 0 0 clamp(22px, 3vw, 32px);
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.75;
  color: var(--ink-soft);
}

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

/* ---------- 桌面布局 ---------- */
@media (min-width: 760px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

  .page-about .partner-list__item {
    grid-template-columns: 220px minmax(0, 1fr);
    align-items: baseline;
    gap: 24px;
  }

  .page-about .fact-list__row {
    grid-template-columns: 200px minmax(0, 1fr);
    align-items: baseline;
    gap: 24px;
  }

  .page-about .about-split-text {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: clamp(24px, 3vw, 44px);
  }
}

@media (min-width: 960px) {
  .page-about .about-shell {
    display: grid;
    grid-template-columns: 210px minmax(0, 1fr);
    gap: clamp(32px, 4vw, 64px);
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: 132px;
    margin-bottom: 0;
  }

  .page-about .about-toc ol {
    display: block;
    overflow: visible;
  }

  .page-about .about-toc li + li {
    margin-top: 2px;
  }

  .page-about .about-chapter__body--split {
    grid-template-columns: minmax(0, 1.04fr) minmax(0, .96fr);
    align-items: start;
    gap: clamp(32px, 4vw, 60px);
  }

  .page-about .about-chapter--flip .about-chapter__body--split > .about-chapter__media {
    order: -1;
  }
}

@media (min-width: 1200px) {
  .page-about .about-chapter__num {
    font-size: 13px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc a {
    transition: none;
  }
}
</main>