.page-about {
  --about-rail: 172px;
  --about-gap: clamp(20px, 4vw, 56px);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(26px, 5vw, 60px) 0 clamp(34px, 6vw, 76px);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(143, 182, 201, .55) 0%, rgba(143, 182, 201, 0) 60%),
    linear-gradient(158deg, var(--ice) 0%, var(--paper) 58%, var(--paper-warm) 100%);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  right: -14%;
  bottom: -26%;
  width: 68%;
  height: 78%;
  background: repeating-linear-gradient(112deg, transparent 0 24px, rgba(169, 80, 59, .13) 24px 25px);
  transform: skewY(-7deg);
  pointer-events: none;
}

.page-about .about-hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 5vw, 52px);
  align-items: center;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2rem, 7.2vw, 4.4rem);
  line-height: 1.06;
  letter-spacing: -.02em;
  margin: .7rem 0 0;
  max-width: 15em;
  color: var(--ink);
}

.page-about .about-hero-lead {
  margin: 1.15rem 0 0;
  max-width: 42em;
  font-size: clamp(1rem, 2.6vw, 1.12rem);
  line-height: 1.82;
  color: rgba(16, 32, 43, .82);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 1.6rem;
}

.page-about .about-hero-figure {
  margin: 0;
}

.page-about .about-hero-figure .figure-frame {
  overflow: hidden;
  border: 1px solid rgba(27, 42, 74, .28);
  background: linear-gradient(140deg, var(--ice-deep), var(--indigo));
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 34px), calc(100% - 34px) 100%, 0 100%);
}

.page-about .about-hero-figure .figure-img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

.page-about .about-hero-figure .figure-caption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  color: rgba(16, 32, 43, .62);
}

.page-about .about-ruler {
  display: flex;
  justify-content: space-between;
  gap: 6px;
  margin-top: 18px;
  padding-top: 10px;
  border-top: 1px solid rgba(16, 32, 43, .26);
}

.page-about .about-ruler-item {
  position: relative;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--indigo);
}

.page-about .about-ruler-item::before {
  content: "";
  position: absolute;
  top: -11px;
  left: 0;
  width: 1px;
  height: 8px;
  background: rgba(16, 32, 43, .42);
}

/* ---------- 编年史 ---------- */
.page-about .about-timeline-head p {
  max-width: 44em;
}

.page-about .about-time-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(18px, 3vw, 30px);
  margin-top: clamp(24px, 4vw, 46px);
}

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

.page-about .about-year-rail .annotation {
  display: none;
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .28em;
  text-transform: uppercase;
  color: rgba(16, 32, 43, .5);
}

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

.page-about .about-year-list li {
  flex: 0 0 auto;
}

.page-about .about-year-link {
  display: flex;
  align-items: baseline;
  gap: 7px;
  padding: 8px 12px;
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-radius: 2px;
  text-decoration: none;
  color: var(--ink);
  white-space: nowrap;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}

.page-about .about-year-link:hover,
.page-about .about-year-link:focus-visible {
  background: var(--ice);
  border-color: var(--gold);
}

.page-about .about-year-num {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -.02em;
  color: var(--indigo);
}

.page-about .about-year-word {
  font-size: 12px;
  color: rgba(16, 32, 43, .6);
}

.page-about .about-time-body {
  min-width: 0;
}

.page-about .about-era {
  position: relative;
  padding: clamp(20px, 3.4vw, 30px) 0;
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: 120px;
}

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

.page-about .about-era-head {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 10px;
}

.page-about .about-era-year {
  font-family: var(--font-mono);
  font-size: clamp(2.1rem, 7.4vw, 3.2rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--indigo);
}

.page-about .about-era h3 {
  font-family: var(--font-display);
  font-size: clamp(1.16rem, 3.4vw, 1.55rem);
  font-weight: 700;
  line-height: 1.35;
  margin: 0 0 .6rem;
  color: var(--ink);
}

.page-about .about-era p {
  margin: 0 0 .7rem;
  max-width: 46em;
  font-size: 1rem;
  line-height: 1.8;
  color: rgba(16, 32, 43, .82);
}

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

/* ---------- 三个阶段（标签页） ---------- */
.page-about .about-stages {
  position: relative;
}

.page-about .about-stages::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 26px;
  background: repeating-linear-gradient(90deg, rgba(27, 42, 74, .16) 0 1px, transparent 1px 18px);
  pointer-events: none;
}

.page-about .about-tabs {
  margin-top: clamp(22px, 4vw, 40px);
}

.page-about .about-tabs .tablist {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 6px;
  border-bottom: 1px solid rgba(27, 42, 74, .2);
}

.page-about .about-tabs .tab {
  padding: 11px 14px;
  background: rgba(247, 243, 234, .5);
  border: 1px solid transparent;
  border-bottom: 3px solid transparent;
  border-radius: 2px 2px 0 0;
  font-family: var(--font-display);
  font-size: clamp(.86rem, 2.6vw, .98rem);
  font-weight: 700;
  letter-spacing: .01em;
  color: rgba(16, 32, 43, .68);
  cursor: pointer;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}

.page-about .about-tabs .tab:hover {
  color: var(--indigo);
  background: var(--paper-warm);
}

.page-about .about-tabs .tab:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 2px;
}

.page-about .about-tabs .tab[aria-selected="true"] {
  background: var(--paper-warm);
  border-color: var(--line-soft);
  border-bottom-color: var(--gold);
  color: var(--indigo);
}

.page-about .about-tabs .tabpanel {
  margin-top: 0;
  padding: clamp(20px, 3.6vw, 36px);
  background: var(--paper-warm);
  border: 1px solid var(--line-soft);
  border-top: 0;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

.page-about .about-tabs .tabpanel h3 {
  margin: 0 0 .7rem;
  font-family: var(--font-display);
  font-size: clamp(1.1rem, 3.2vw, 1.4rem);
  font-weight: 700;
  color: var(--indigo);
}

.page-about .about-tabs .tabpanel p {
  margin: 0 0 .9rem;
  max-width: 50em;
  line-height: 1.8;
  color: rgba(16, 32, 43, .82);
}

.page-about .about-panel-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}

.page-about .about-panel-list li {
  position: relative;
  padding-left: 20px;
  font-size: .95rem;
  line-height: 1.72;
  color: rgba(16, 32, 43, .78);
}

.page-about .about-panel-list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: .68em;
  width: 9px;
  height: 2px;
  background: var(--terracotta);
}

/* ---------- 团队 ---------- */
.page-about .about-team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
}

.page-about .about-team h2 {
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 4.6vw, 2.6rem);
  line-height: 1.2;
  letter-spacing: -.01em;
  margin: .5rem 0 .9rem;
  color: var(--ink);
}

.page-about .about-team-copy p {
  margin: 0 0 .85rem;
  max-width: 42em;
  line-height: 1.82;
  color: rgba(16, 32, 43, .82);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 1.6rem 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-stats li {
  background: var(--ice);
  padding: 16px 14px;
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.7rem, 5.4vw, 2.4rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--indigo);
}

.page-about .about-stat-label {
  display: block;
  margin-top: 8px;
  font-size: .84rem;
  line-height: 1.55;
  color: rgba(16, 32, 43, .76);
}

.page-about .about-team-figure {
  margin: 0;
}

.page-about .about-team-figure .figure-frame {
  overflow: hidden;
  border: 1px solid rgba(27, 42, 74, .22);
  background: linear-gradient(120deg, var(--ice-deep), var(--ice));
  clip-path: polygon(0 0, calc(100% - 30px) 0, 100% 30px, 100% 100%, 0 100%);
}

.page-about .about-team-figure .figure-img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
}

.page-about .about-team-figure .figure-caption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  color: rgba(16, 32, 43, .6);
}

/* ---------- 数据质量 ---------- */
.page-about .about-quality {
  border-top: 1px solid var(--line-soft);
}

.page-about .about-quality-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
}

.page-about .about-quality-copy h2 {
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 4.6vw, 2.5rem);
  line-height: 1.22;
  letter-spacing: -.01em;
  margin: .5rem 0 .9rem;
  color: var(--ink);
}

.page-about .about-quality-copy > p {
  margin: 0 0 1.2rem;
  max-width: 44em;
  line-height: 1.82;
  color: rgba(16, 32, 43, .82);
}

.page-about .about-flow {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 0 0 1.4rem;
  padding: 0;
  list-style: none;
  background: var(--line);
  border-top: 3px solid var(--gold);
}

.page-about .about-flow-step {
  background: var(--paper-warm);
  padding: 18px 16px;
}

.page-about .about-flow-index {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--terracotta);
}

.page-about .about-flow-step h3 {
  margin: 6px 0 .4rem;
  font-family: var(--font-display);
  font-size: 1.06rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-flow-step p {
  margin: 0;
  font-size: .92rem;
  line-height: 1.72;
  color: rgba(16, 32, 43, .76);
}

.page-about .about-note {
  border: 1px solid var(--line);
  border-left: 3px solid var(--terracotta);
  background: rgba(220, 233, 242, .55);
  padding: 12px 16px;
  max-width: 46em;
}

.page-about .about-note summary {
  cursor: pointer;
  font-family: var(--font-display);
  font-size: .95rem;
  font-weight: 700;
  color: var(--indigo);
  list-style: none;
}

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

.page-about .about-note summary::before {
  content: "+";
  display: inline-block;
  width: 1.1em;
  font-family: var(--font-mono);
  color: var(--terracotta);
}

.page-about .about-note[open] summary::before {
  content: "−";
}

.page-about .about-note summary:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
}

.page-about .about-note p {
  margin: .7rem 0 0;
  font-size: .92rem;
  line-height: 1.78;
  color: rgba(16, 32, 43, .8);
}

.page-about .about-quality-figure {
  margin: 0;
}

.page-about .about-quality-figure .figure-frame {
  overflow: hidden;
  border: 1px solid rgba(27, 42, 74, .22);
  background: linear-gradient(160deg, var(--indigo), var(--ice-deep));
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 32px), calc(100% - 32px) 100%, 0 100%);
}

.page-about .about-quality-figure .figure-img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.page-about .about-quality-figure .figure-caption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  color: rgba(16, 32, 43, .6);
}

/* ---------- 合作生态 ---------- */
.page-about .about-partner-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin: clamp(22px, 4vw, 38px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-partner-list li {
  position: relative;
  padding: 16px 18px 16px 20px;
  background: var(--paper-warm);
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--gold);
}

.page-about .about-partner-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 5vw, 2.2rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--indigo);
}

.page-about .about-partner-label {
  display: block;
  margin-top: 8px;
  font-size: .9rem;
  line-height: 1.65;
  color: rgba(16, 32, 43, .78);
}

.page-about .about-partner-foot {
  margin: clamp(18px, 3vw, 28px) 0 0;
  max-width: 52em;
  padding-top: 16px;
  border-top: 1px dashed rgba(27, 42, 74, .3);
  font-size: .95rem;
  line-height: 1.8;
  color: rgba(16, 32, 43, .8);
}

/* ---------- 下一阶段 ---------- */
.page-about .about-next {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--indigo) 0%, #22345A 100%);
  color: var(--paper);
}

.page-about .about-next::before {
  content: "";
  position: absolute;
  right: -12%;
  top: -30%;
  width: 60%;
  height: 180%;
  background: repeating-linear-gradient(108deg, transparent 0 26px, rgba(232, 199, 122, .18) 26px 27px);
  pointer-events: none;
}

.page-about .about-next-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 4vw, 44px);
  align-items: center;
}

.page-about .about-next .kicker {
  color: var(--gold-light);
}

.page-about .about-next h2 {
  margin: .5rem 0 .9rem;
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 4.8vw, 2.6rem);
  line-height: 1.2;
  letter-spacing: -.01em;
  color: var(--paper-warm);
}

.page-about .about-next p {
  margin: 0;
  max-width: 46em;
  font-size: 1rem;
  line-height: 1.85;
  color: rgba(247, 243, 234, .84);
}

.page-about .about-next-actions {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 14px;
}

.page-about .about-next-link {
  display: inline-block;
  font-family: var(--font-display);
  font-size: .95rem;
  font-weight: 700;
  color: var(--gold-light);
  text-decoration: none;
  border-bottom: 1px solid rgba(232, 199, 122, .55);
  padding-bottom: 2px;
}

.page-about .about-next-link:hover,
.page-about .about-next-link:focus-visible {
  border-bottom-color: var(--paper-warm);
  color: var(--paper-warm);
}

.page-about .about-next-link:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 4px;
}

/* ---------- 减少动态 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-year-link,
  .page-about .about-tabs .tab {
    transition: none;
  }
}

/* ---------- 平板 ---------- */
@media (min-width: 700px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

  .page-about .about-next-actions {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    gap: 20px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 960px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.04fr) minmax(0, .96fr);
    align-items: center;
  }

  .page-about .about-team-grid,
  .page-about .about-quality-grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
    align-items: start;
  }

  .page-about .about-quality-figure {
    position: sticky;
    top: 110px;
  }

  .page-about .about-next-inner {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, .7fr);
  }
}

@media (min-width: 1000px) {
  .page-about .about-time-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(28px, 4vw, 64px);
    align-items: start;
  }

  .page-about .about-year-rail {
    position: sticky;
    top: 104px;
    align-self: start;
  }

  .page-about .about-year-rail .annotation {
    display: block;
  }

  .page-about .about-year-list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-year-link {
    justify-content: space-between;
    width: 100%;
    border-color: transparent;
    border-bottom: 1px solid var(--line-soft);
    border-radius: 0;
    background: transparent;
    padding: 10px 4px;
  }

  .page-about .about-year-num {
    font-size: 1.32rem;
  }

  .page-about .about-year-link:hover,
  .page-about .about-year-link:focus-visible {
    background: var(--ice);
    border-bottom-color: var(--gold);
  }

  .page-about .about-era:nth-of-type(even) {
    background: var(--paper-warm);
    border: 1px solid var(--line-soft);
    border-top-color: var(--line-soft);
    padding: clamp(24px, 3vw, 36px);
    margin-left: clamp(0px, 2.6vw, 40px);
    clip-path: polygon(0 0, 100% 0, 100% calc(100% - 28px), calc(100% - 28px) 100%, 0 100%);
  }

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