.page-about {
  --rail-width: 216px;
  --card-bg: rgba(18, 38, 64, .58);
  color: var(--paper-100);
  padding-bottom: clamp(2.5rem, 5vw, 4.5rem);
}

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

.page-about figure {
  margin: clamp(1.25rem, 3vw, 2rem) 0 0;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-m);
  overflow: hidden;
  background: var(--ink-800);
}

.page-about figure img {
  width: 100%;
  object-fit: cover;
}

.page-about figcaption {
  padding: .6rem .9rem;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .06em;
  color: var(--warm-500);
  border-top: 1px solid var(--line-soft);
}

/* ---------- 首屏分屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: clamp(1.5rem, 4vw, 2.5rem);
  padding: clamp(1rem, 2.5vw, 1.75rem) 0 clamp(2rem, 4vw, 3rem);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero__main {
  display: grid;
  gap: .9rem;
  align-content: start;
  min-width: 0;
}

.page-about .about-eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .16em;
  color: var(--cyan-400);
}

.page-about h1 {
  margin: 0;
  font-size: clamp(1.85rem, 4.4vw, 3rem);
  line-height: 1.24;
  letter-spacing: .04em;
  font-weight: 700;
  color: var(--paper-100);
}

.page-about .about-lede {
  margin: 0;
  max-width: 44em;
  font-size: 1rem;
  line-height: 1.9;
  letter-spacing: .01em;
  color: var(--warm-200);
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: .35rem;
}

.page-about .about-hero__aside {
  min-width: 0;
  padding: 1rem 1.1rem 1.15rem;
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--cyan-400);
  border-radius: var(--radius-m);
  background:
    linear-gradient(155deg, var(--tint-cyan), rgba(8, 20, 38, 0) 62%),
    var(--ink-700);
}

.page-about .aside-label {
  margin: 0 0 .35rem;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .14em;
  color: var(--warm-500);
}

.page-about .aside-version {
  margin: 0 0 .9rem;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  letter-spacing: .02em;
  color: var(--paper-100);
}

.page-about .aside-version span {
  display: block;
  margin-top: .2rem;
  font-size: .75rem;
  letter-spacing: .08em;
  color: var(--cyan-400);
}

.page-about .aside-facts {
  margin: 0;
  display: grid;
  gap: .55rem;
}

.page-about .aside-facts > div {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: .75rem;
  padding-top: .55rem;
  border-top: 1px solid var(--line-soft);
  font-size: .8125rem;
}

.page-about .aside-facts dt {
  color: var(--warm-500);
}

.page-about .aside-facts dd {
  margin: 0;
  font-family: var(--font-mono);
  letter-spacing: .02em;
  color: var(--warm-200);
}

/* ---------- 分栏骨架 ---------- */
.page-about .about-layout {
  display: grid;
  gap: clamp(1.5rem, 3vw, 2.5rem);
  padding-top: clamp(1.75rem, 4vw, 3rem);
}

.page-about .about-rail {
  align-self: start;
  display: grid;
  gap: .55rem;
  min-width: 0;
}

.page-about .rail-title {
  margin: .55rem 0 0;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .16em;
  color: var(--warm-500);
}

.page-about .rail-title:first-child {
  margin-top: 0;
}

.page-about .rail-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .1rem;
}

.page-about .rail-list a {
  display: flex;
  align-items: baseline;
  gap: .5rem;
  padding: .38rem .1rem;
  font-size: .875rem;
  color: var(--warm-200);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .rail-list a:hover,
.page-about .rail-list a:focus-visible {
  color: var(--paper-100);
  border-bottom-color: var(--cyan-400);
}

.page-about .rail-year {
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .04em;
  color: var(--cyan-400);
}

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

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  padding: clamp(1.75rem, 4vw, 2.75rem) 0;
  border-top: 1px solid var(--line-soft);
}

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

.page-about .section-head {
  display: grid;
  gap: .45rem;
  margin-bottom: clamp(1.25rem, 3vw, 1.9rem);
}

.page-about .about-section .section-index {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .16em;
  color: var(--warm-500);
}

.page-about h2 {
  margin: 0;
  font-size: clamp(1.4rem, 2.6vw, 1.95rem);
  line-height: 1.35;
  letter-spacing: .05em;
  font-weight: 700;
  color: var(--paper-100);
}

.page-about .about-section .section-note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .06em;
  color: var(--warm-500);
}

.page-about .about-section p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.85;
  letter-spacing: .01em;
  color: var(--warm-200);
}

.page-about h3 {
  margin: 0;
  font-size: 1.0625rem;
  line-height: 1.5;
  letter-spacing: .04em;
  font-weight: 700;
  color: var(--paper-100);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 1.1rem;
  border-left: 1px solid var(--line-strong);
  display: grid;
  gap: clamp(1.25rem, 3vw, 1.9rem);
}

.page-about .timeline-item {
  position: relative;
  padding-left: .2rem;
  scroll-margin-top: 96px;
}

.page-about .timeline-item::before {
  content: "";
  position: absolute;
  left: calc(-1.1rem - 4.5px);
  top: .5rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 1px solid var(--cyan-400);
  transition: background .2s var(--ease), box-shadow .2s var(--ease);
}

.page-about .timeline-item:target::before {
  background: var(--cyan-400);
  box-shadow: 0 0 0 4px var(--tint-cyan);
}

.page-about .timeline-year {
  margin: 0 0 .2rem;
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .1em;
  color: var(--cyan-400);
}

.page-about .timeline-item h3 {
  margin-bottom: .4rem;
}

/* ---------- 版本说明 ---------- */
.page-about .about-section--edition {
  display: grid;
  gap: clamp(1.5rem, 3vw, 2.25rem);
}

.page-about .edition-copy {
  min-width: 0;
}

.page-about .spec {
  margin-top: .55rem;
  padding: .75rem 1rem .85rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-s);
  background: var(--card-bg);
}

.page-about .spec summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  cursor: pointer;
  list-style: none;
  font-size: .9375rem;
  letter-spacing: .04em;
  color: var(--paper-100);
}

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

.page-about .spec summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--cyan-400);
}

.page-about .spec[open] summary::after {
  content: "–";
}

.page-about .spec-tag {
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .06em;
  color: var(--cyan-400);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-s);
  padding: .1rem .4rem;
  white-space: nowrap;
}

.page-about .about-section .spec p {
  margin-top: .6rem;
  font-size: .875rem;
  line-height: 1.8;
}

.page-about .edition-figure {
  margin-top: 0;
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  gap: .75rem;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .team-card {
  display: grid;
  gap: .35rem;
  align-content: start;
  padding: 1.1rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-m);
  background: var(--card-bg);
}

.page-about .team-card--total {
  background:
    linear-gradient(160deg, var(--tint-cyan), rgba(8, 20, 38, 0) 70%),
    var(--ink-700);
  border-color: rgba(55, 227, 210, .34);
}

.page-about .team-head {
  display: flex;
  align-items: baseline;
  gap: .6rem;
}

.page-about .team-num {
  font-family: var(--font-mono);
  font-size: 1.85rem;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--paper-100);
}

.page-about .about-section .team-card p {
  font-size: .8125rem;
  line-height: 1.8;
  color: var(--warm-200);
}

/* ---------- 覆盖 ---------- */
.page-about .coverage-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .coverage-cell {
  display: grid;
  gap: .2rem;
  align-content: start;
  padding: .95rem 1rem;
  background: var(--ink-800);
}

.page-about .coverage-num {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  letter-spacing: .02em;
  color: var(--cyan-400);
}

.page-about .coverage-label {
  font-size: .75rem;
  line-height: 1.6;
  color: var(--warm-500);
}

.page-about .about-section .coverage-note {
  margin-top: 1rem;
  font-size: .875rem;
}

/* ---------- 校验流程 ---------- */
.page-about .check-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .75rem;
}

.page-about .check-steps li {
  padding: 1.1rem 1.1rem 1.15rem 1.2rem;
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--cyan-400);
  border-radius: var(--radius-m);
  background: var(--card-bg);
}

.page-about .step-no {
  display: block;
  margin-bottom: .3rem;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .12em;
  color: var(--cyan-400);
}

.page-about .check-steps h3 {
  margin-bottom: .35rem;
}

.page-about .about-section .check-steps p {
  font-size: .875rem;
}

.page-about .about-section .governance-note {
  margin-top: 1rem;
  font-size: .875rem;
}

/* ---------- 收尾行动 ---------- */
.page-about .about-cta {
  display: grid;
  gap: 1rem;
  margin-top: clamp(1.75rem, 4vw, 2.75rem);
  padding: clamp(1.4rem, 3.5vw, 2.25rem);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-l);
  background:
    radial-gradient(120% 140% at 0% 0%, rgba(255, 107, 44, .13), rgba(8, 20, 38, 0) 58%),
    var(--ink-700);
}

.page-about .about-cta p {
  margin: .55rem 0 0;
  max-width: 46em;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--warm-200);
}

.page-about .about-cta .about-actions {
  margin-top: 0;
}

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

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

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: 240px minmax(0, 1fr);
    align-items: start;
    column-gap: clamp(1.5rem, 3vw, 2.5rem);
  }

  .page-about .about-hero__main {
    grid-column: 2;
    grid-row: 1;
  }

  .page-about .about-hero__aside {
    grid-column: 1;
    grid-row: 1;
  }

  .page-about .about-section--edition {
    grid-template-columns: minmax(0, 1fr) minmax(0, .82fr);
    align-items: start;
  }

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

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 2rem;
  }

  .page-about .about-cta .about-actions {
    justify-content: flex-end;
  }
}

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: var(--rail-width) minmax(0, 1fr);
    column-gap: clamp(2rem, 4vw, 3.5rem);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 96px;
    padding-left: 1rem;
    border-left: 1px solid var(--line-soft);
  }

  .page-about .rail-title:first-child {
    margin-top: 0;
  }
}

@media (min-width: 1180px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .rail-list a,
  .page-about .timeline-item::before {
    transition: none;
  }
}