.page-about {
  --about-rail: 200px;
  --about-gap: clamp(24px, 4vw, 56px);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding-block: clamp(16px, 2.4vw, 28px) 0;
}

/* ---------- 首屏框景窗口 ---------- */
.page-about .about-hero {
  padding-block: clamp(20px, 3vw, 36px) clamp(48px, 7vw, 88px);
}

.page-about .about-hero__window {
  border: 2px solid var(--ridge);
  background:
    radial-gradient(120% 120% at 8% -10%, rgba(46, 92, 120, 0.5), transparent 58%),
    linear-gradient(168deg, var(--night) 0%, var(--deep) 68%);
  box-shadow: var(--shadow-hard-lg);
}

.page-about .about-hero__head {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 18px;
  border-bottom: 2px solid var(--ridge);
  background: var(--deep);
}

.page-about .about-hero__label {
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ice);
  white-space: nowrap;
}

.page-about .about-hero__ticks {
  flex: 1 1 auto;
  min-width: 24px;
  height: 10px;
  background-image: repeating-linear-gradient(
    to right,
    var(--ridge) 0 1px,
    transparent 1px 8px
  );
}

.page-about .about-hero__state {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--neon);
  border: 1.5px solid var(--neon);
  padding: 2px 8px;
  white-space: nowrap;
}

.page-about .about-hero__body {
  padding: clamp(28px, 5vw, 56px) clamp(20px, 4vw, 56px) clamp(32px, 5vw, 60px);
}

.page-about .about-hero__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: clamp(30px, 5.4vw, 64px);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: 0.01em;
  color: var(--ice);
  max-width: 20ch;
}

.page-about .about-hero__lede {
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  max-width: 46ch;
  font-size: 17px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 0;
  background: var(--ridge);
  border: 2px solid var(--ridge);
}

.page-about .about-hero__stat {
  background: var(--card);
  padding: 16px 18px;
}

.page-about .about-hero__stat-label {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--mist);
  text-transform: uppercase;
}

.page-about .about-hero__stat-num {
  margin: 6px 0 0;
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.4vw, 40px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--sunset);
}

.page-about .about-hero__stat-num small {
  font-size: 0.46em;
  margin-left: 4px;
  color: var(--sand);
}

@media (min-width: 760px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 纵向时间轴 ---------- */
.page-about .about-track {
  padding-bottom: clamp(24px, 4vw, 56px);
}

.page-about .about-record {
  padding-block: clamp(30px, 4.6vw, 56px);
  border-top: 2px solid var(--ridge);
}

.page-about .about-record:first-child {
  border-top: none;
  padding-top: 0;
}

.page-about .about-record__rail {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 14px;
  margin-bottom: 18px;
  border-bottom: 2px solid var(--ridge);
  outline: none;
}

.page-about .about-record__year {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1;
  color: var(--sunset);
}

.page-about .about-record__stage {
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .about-record__hint {
  display: block;
  flex-basis: 100%;
  margin-top: 6px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .about-record__rail:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 6px;
}

.page-about .about-record__title {
  margin: 0 0 clamp(14px, 2vw, 22px);
  font-family: var(--font-display);
  font-size: clamp(24px, 3.4vw, 40px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: 0.01em;
  color: var(--ice);
}

.page-about .about-record__lede {
  margin: 0 0 clamp(18px, 2.4vw, 26px);
  max-width: 52ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--sand);
}

.page-about .about-record__content .prose p {
  margin: 0 0 1.1em;
  max-width: 44ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--mist);
}

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

@media (min-width: 860px) {
  .page-about .about-track {
    position: relative;
  }

  .page-about .about-track::before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    left: calc(var(--about-rail) + var(--about-gap) / 2);
    width: 2px;
    background: linear-gradient(
      to bottom,
      var(--ridge) 0%,
      var(--ridge) 88%,
      transparent 100%
    );
  }

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

  .page-about .about-record__rail {
    flex-direction: column;
    align-items: flex-end;
    gap: 8px;
    text-align: right;
    padding-bottom: 0;
    margin-bottom: 0;
    border-bottom: none;
    padding-top: 4px;
  }

  .page-about .about-record__hint {
    margin-top: 4px;
    max-width: 22ch;
    opacity: 0;
    max-height: 0;
    overflow: hidden;
    transition: opacity 180ms ease, max-height 180ms ease;
  }

  .page-about .about-record__rail:hover .about-record__hint,
  .page-about .about-record__rail:focus-visible .about-record__hint,
  .page-about .about-record__rail:focus-within .about-record__hint {
    opacity: 1;
    max-height: 80px;
  }

  .page-about .about-record__rail::after {
    content: "";
    position: absolute;
    top: 12px;
    right: calc(var(--about-gap) / -2 - 7px);
    width: 14px;
    height: 14px;
    background: var(--sunset);
    border: 2px solid var(--deep);
    z-index: 2;
    transition: background 140ms ease;
  }

  .page-about .about-record__rail:hover::after,
  .page-about .about-record__rail:focus-visible::after {
    background: var(--neon);
  }
}

/* ---------- 团队 / 环形图 ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
  margin: clamp(20px, 3vw, 32px) 0;
  padding: clamp(20px, 3vw, 32px);
  border: 2px solid var(--ridge);
  background: var(--night);
  box-shadow: var(--shadow-hard);
}

.page-about .about-team__figure {
  margin: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.page-about .about-doughnut {
  width: min(240px, 70vw);
  height: auto;
  display: block;
}

.page-about .about-doughnut__num {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  fill: var(--ice);
  letter-spacing: 0.04em;
}

.page-about .about-doughnut__unit {
  font-family: var(--font-body);
  font-size: 11px;
  fill: var(--mist);
}

.page-about .about-team__caption {
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--mist);
}

.page-about .about-team__legend {
  display: grid;
  gap: 10px;
  align-content: center;
}

.page-about .about-team__item {
  display: grid;
  grid-template-columns: 14px 1fr auto;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border: 1.5px solid var(--ridge);
  background: var(--card);
  transition: background 140ms ease, border-color 140ms ease;
}

.page-about .about-team__item:hover {
  background: var(--dusk);
  border-color: var(--neon);
}

.page-about .about-team__swatch {
  width: 14px;
  height: 14px;
  display: block;
  border: 1.5px solid var(--deep);
}

.page-about .about-team__swatch[data-tone="data"] { background: #2E5C78; }
.page-about .about-team__swatch[data-tone="ops"] { background: #F4813C; }
.page-about .about-team__swatch[data-tone="label"] { background: #E8EEF2; }

.page-about .about-team__name {
  font-size: 15px;
  color: var(--ice);
}

.page-about .about-team__count {
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 700;
  color: var(--sunset);
}

@media (min-width: 760px) {
  .page-about .about-team {
    grid-template-columns: minmax(220px, 260px) 1fr;
    align-items: center;
  }
}

.page-about .about-team__shot {
  margin: clamp(20px, 3vw, 32px) 0 0;
  border: 2px solid var(--ridge);
}

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

/* ---------- 版本对照表 ---------- */
.page-about .about-version-wrap {
  margin: clamp(20px, 3vw, 32px) 0;
  border: 2px solid var(--ridge);
  box-shadow: var(--shadow-hard);
  overflow-x: auto;
  background: var(--night);
}

.page-about .about-version {
  width: 100%;
  min-width: 520px;
  border-collapse: collapse;
  font-size: 15px;
}

.page-about .about-version thead th {
  padding: 12px 16px;
  text-align: left;
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
  background: var(--deep);
  border-bottom: 2px solid var(--ridge);
}

.page-about .about-version tbody th,
.page-about .about-version tbody td {
  padding: 14px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--ridge);
}

.page-about .about-version tbody th {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--sunset);
  white-space: nowrap;
}

.page-about .about-version tbody td {
  color: var(--mist);
  line-height: 1.75;
}

.page-about .about-version tbody tr:last-child th,
.page-about .about-version tbody tr:last-child td {
  border-bottom: none;
}

.page-about .about-version tbody tr {
  transition: background 140ms ease;
}

.page-about .about-version tbody tr:hover {
  background: var(--dusk);
}

.page-about .about-version__figure {
  margin: 0 0 clamp(20px, 3vw, 32px);
  border: 2px solid var(--ridge);
}

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

/* ---------- 覆盖范围 ---------- */
.page-about .about-coverage {
  display: grid;
  gap: 2px;
  margin: clamp(20px, 3vw, 32px) 0;
  background: var(--ridge);
  border: 2px solid var(--ridge);
}

.page-about .about-coverage__cell {
  background: var(--card);
  padding: clamp(18px, 2.6vw, 26px);
  display: grid;
  gap: 6px;
  align-content: start;
}

.page-about .about-coverage__num {
  font-family: var(--font-mono);
  font-size: clamp(30px, 4vw, 44px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--sunset);
}

.page-about .about-coverage__label {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--ice);
}

.page-about .about-coverage__note {
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

@media (min-width: 760px) {
  .page-about .about-coverage {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 合作分工卡片 ---------- */
.page-about .about-partners {
  display: grid;
  gap: clamp(16px, 2.4vw, 24px);
  margin: clamp(20px, 3vw, 32px) 0;
}

.page-about .about-partners__card {
  padding: clamp(20px, 3vw, 28px);
  border: 2px solid var(--ridge);
  background: var(--night);
  box-shadow: var(--shadow-hard);
  transition: transform 160ms ease, box-shadow 160ms ease, border-color 160ms ease;
}

.page-about .about-partners__card:hover {
  transform: translate(-3px, -3px);
  box-shadow: var(--shadow-hard-lg);
  border-color: var(--neon);
}

.page-about .about-partners__card:focus-within {
  border-color: var(--neon);
}

.page-about .about-partners__title {
  margin: 14px 0 10px;
  font-family: var(--font-display);
  font-size: clamp(19px, 2.2vw, 24px);
  font-weight: 700;
  line-height: 1.3;
  color: var(--ice);
}

.page-about .about-partners__card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

@media (min-width: 760px) {
  .page-about .about-partners {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 收尾区 ---------- */
.page-about .about-close {
  margin-top: clamp(40px, 6vw, 80px);
  border-top: 2px solid var(--ridge);
  background: linear-gradient(180deg, var(--deep) 0%, var(--night) 100%);
}

.page-about .about-close__band {
  display: block;
  border-bottom: 2px solid var(--ridge);
  background: var(--night);
}

.page-about .about-close__band img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 340px;
  object-fit: cover;
}

.page-about .about-close__body {
  padding-block: clamp(32px, 5vw, 64px);
}

.page-about .about-close__title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 34px);
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--ice);
}

.page-about .about-close__lede {
  margin: 0 0 clamp(20px, 3vw, 30px);
  max-width: 52ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--mist);
}

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-record__hint,
  .page-about .about-record__rail::after,
  .page-about .about-team__item,
  .page-about .about-version tbody tr,
  .page-about .about-partners__card {
    transition: none;
  }

  .page-about .about-partners__card:hover {
    transform: none;
  }
}