.page-about {
  --about-rule: 1px solid var(--line);
  --about-rail-w: 190px;
  background: var(--ink);
  color: var(--cream);
  font-family: var(--font-sans);
  padding-bottom: 4rem;
}

.page-about .container {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding-left: 20px;
  padding-right: 20px;
  box-sizing: border-box;
}

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  position: relative;
  border-bottom: var(--about-rule);
  padding: 2.25rem 0 2rem;
  background:
    repeating-linear-gradient(90deg, rgba(28, 59, 46, .5) 0 1px, transparent 1px 64px),
    linear-gradient(180deg, #0A1A14 0%, var(--ink) 100%);
  overflow: hidden;
}

.page-about .about-intro::after {
  content: "";
  position: absolute;
  right: -6%;
  top: -30%;
  width: 340px;
  height: 340px;
  background: radial-gradient(circle, rgba(155, 229, 100, .13), transparent 68%);
  pointer-events: none;
}

.page-about .about-intro > .container {
  position: relative;
  z-index: 1;
}

.page-about .breadcrumb {
  font-size: .8rem;
  color: var(--stone);
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  align-items: center;
  margin-bottom: 1.5rem;
}

.page-about .breadcrumb a {
  color: var(--stone);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--ease), border-color var(--ease);
}

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

.page-about .about-intro h1 {
  font-size: clamp(2rem, 8vw, 4.2rem);
  line-height: 1.06;
  font-weight: 900;
  letter-spacing: -0.03em;
  margin: .6rem 0 1.1rem;
  max-width: 17ch;
  color: var(--cream);
}

.page-about .lede {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--stone);
  margin: 0 0 2rem;
}

.page-about .about-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: var(--about-rule);
}

.page-about .about-facts__item {
  background: var(--ink);
  padding: .9rem .8rem 1rem;
  display: flex;
  flex-direction: column;
  gap: .35rem;
}

.page-about .about-facts__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.7rem;
  line-height: 1;
  font-weight: 700;
  color: var(--cream);
  letter-spacing: -0.02em;
}

.page-about .about-facts__unit {
  font-size: .8rem;
  color: var(--lime);
  margin-left: .15rem;
  font-weight: 400;
}

.page-about .about-facts__label {
  font-size: .78rem;
  line-height: 1.5;
  color: var(--stone);
}

/* ---------- 主体分栏 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2rem;
  padding-top: 2rem;
}

/* ---------- 左侧刻度栏 ---------- */
.page-about .about-rail {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  border-bottom: var(--about-rule);
  padding-bottom: 1.25rem;
}

.page-about .about-rail__label {
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--clay);
  margin: 0 0 .6rem;
}

.page-about .about-rail__years,
.page-about .about-rail__nav {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: .5rem;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail__year {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: .85rem;
  color: var(--stone);
  text-decoration: none;
  padding: .35rem .6rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  white-space: nowrap;
  transition: color var(--ease), border-color var(--ease), background var(--ease);
}

.page-about .about-rail__tick {
  display: inline-block;
  width: 10px;
  height: 1px;
  background: var(--clay);
  transition: background var(--ease), width var(--ease);
}

.page-about .about-rail__year:hover,
.page-about .about-rail__year:focus-visible {
  color: var(--lime);
  border-color: var(--lime);
}

.page-about .about-rail__year:hover .about-rail__tick,
.page-about .about-rail__year:focus-visible .about-rail__tick {
  background: var(--lime);
  width: 16px;
}

.page-about .about-rail__nav a {
  display: inline-block;
  font-size: .82rem;
  color: var(--stone);
  text-decoration: none;
  padding: .3rem .55rem;
  border-left: 1px solid var(--line);
  white-space: nowrap;
  transition: color var(--ease), border-color var(--ease);
}

.page-about .about-rail__nav a:hover,
.page-about .about-rail__nav a:focus-visible,
.page-about .about-rail__nav a[aria-current="true"] {
  color: var(--lime);
  border-color: var(--lime);
}

/* ---------- 章节 ---------- */
.page-about .about-body {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 3rem;
}

.page-about .about-section {
  scroll-margin-top: 96px;
}

.page-about .about-section__head {
  margin-bottom: 1.75rem;
}

.page-about .about-section__title {
  font-size: clamp(1.35rem, 5vw, 2rem);
  line-height: 1.25;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--cream);
  margin: .4rem 0 .9rem;
  max-width: 20ch;
}

.page-about .about-section__head .measure,
.page-about .about-section .measure {
  color: var(--stone);
  line-height: 1.8;
  margin: 0;
  max-width: 34em;
}

.page-about .eyebrow {
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .18em;
  color: var(--lime);
  text-transform: uppercase;
  margin: 0;
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0 0 2rem;
  padding: 0 0 0 1.25rem;
  border-left: 1px solid var(--line);
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 1.85rem;
  scroll-margin-top: 96px;
}

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -1.25rem;
  top: .6rem;
  width: 14px;
  height: 1px;
  background: var(--lime);
  transition: width var(--ease), background var(--ease);
}

.page-about .timeline__item:target::before {
  width: 26px;
  background: var(--signal);
}

.page-about .timeline__item:target {
  background: linear-gradient(90deg, rgba(255, 122, 26, .12), transparent 70%);
  padding-left: .75rem;
  margin-left: -.75rem;
}

.page-about .timeline__year {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--lime);
  margin: 0 0 .45rem;
}

.page-about .timeline__title {
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--cream);
  margin: 0 0 .45rem;
  letter-spacing: .01em;
}

.page-about .timeline__text {
  margin: 0;
  font-size: .92rem;
  line-height: 1.8;
  color: var(--stone);
  max-width: 34em;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 1.75rem 0 0;
  border: var(--about-rule);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 3 / 2;
}

.page-about .about-figure--wide img {
  aspect-ratio: 14 / 9;
}

.page-about .about-figure--side img {
  aspect-ratio: 1 / 1;
}

.page-about .about-figure figcaption {
  font-size: .78rem;
  line-height: 1.6;
  color: var(--clay);
  padding: .7rem .85rem;
  border-top: var(--about-rule);
}

/* ---------- 团队名册 ---------- */
.page-about .roster {
  margin: 1.75rem 0 0;
  border-top: var(--about-rule);
}

.page-about .roster__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .35rem;
  padding: 1rem 0;
  border-bottom: var(--about-rule);
}

.page-about .roster__role {
  font-family: var(--font-mono);
  font-size: .82rem;
  letter-spacing: .08em;
  color: var(--lime);
  font-weight: 700;
}

.page-about .roster__desc {
  margin: 0;
  font-size: .92rem;
  line-height: 1.8;
  color: var(--stone);
}

/* ---------- 发布检查单 ---------- */
.page-about .release {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.5rem;
  align-items: start;
}

.page-about .release__hint {
  font-size: .82rem;
  color: var(--clay);
  margin: 0 0 .5rem;
}

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

.page-about .checklist {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--about-rule);
}

.page-about .checklist__item {
  border-bottom: var(--about-rule);
}

.page-about .checklist summary {
  display: flex;
  align-items: baseline;
  gap: .75rem;
  padding: .85rem 0;
  cursor: pointer;
  font-size: .94rem;
  font-weight: 700;
  color: var(--cream);
  list-style: none;
  transition: color var(--ease);
}

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

.page-about .checklist summary:hover,
.page-about .checklist summary:focus-visible {
  color: var(--lime);
}

.page-about .checklist details[open] summary {
  color: var(--lime);
}

.page-about .checklist__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: .78rem;
  color: var(--signal);
  flex: none;
}

.page-about .checklist details p {
  margin: 0 0 .9rem;
  padding-left: 1.9rem;
  font-size: .88rem;
  line-height: 1.8;
  color: var(--stone);
}

/* ---------- 校对刻度 ---------- */
.page-about .sync__axis {
  position: relative;
  height: 2px;
  background: var(--line);
  margin: 1rem 0 3rem;
}

.page-about .sync__point {
  position: absolute;
  top: 50%;
  width: 10px;
  height: 10px;
  margin-left: -5px;
  margin-top: -5px;
  border-radius: 50%;
  background: var(--lime);
  box-shadow: 0 0 0 4px rgba(155, 229, 100, .12);
}

.page-about .sync__point--morning {
  left: 33.333%;
}

.page-about .sync__point--evening {
  left: 75%;
  background: var(--signal);
  box-shadow: 0 0 0 4px rgba(255, 122, 26, .14);
}

.page-about .sync__time {
  position: absolute;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: .85rem;
  color: var(--cream);
  white-space: nowrap;
}

.page-about .sync__cards {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: var(--about-rule);
}

.page-about .sync__card {
  background: var(--panel);
  border: 0;
  padding: 1.1rem 1rem 1.2rem;
}

.page-about .sync__card-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.9rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cream);
  margin: 0 0 .6rem;
}

.page-about .sync__card-unit {
  font-size: .72rem;
  font-weight: 400;
  color: var(--lime);
  margin-left: .25rem;
  letter-spacing: .02em;
}

.page-about .sync__card p:last-child {
  margin: 0;
  font-size: .86rem;
  line-height: 1.75;
  color: var(--stone);
}

/* ---------- 覆盖 ---------- */
.page-about .coverage {
  border: var(--about-rule);
  background: var(--panel);
}

.page-about .coverage-map {
  position: relative;
  height: 140px;
  border-bottom: var(--about-rule);
  background-color: #0A1A14;
  background-image:
    repeating-linear-gradient(90deg, rgba(28, 59, 46, .9) 0 1px, transparent 1px 38px),
    repeating-linear-gradient(0deg, rgba(28, 59, 46, .9) 0 1px, transparent 1px 38px);
  overflow: hidden;
}

.page-about .coverage-map::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 24% 42%, rgba(155, 229, 100, .3), transparent 44%),
    radial-gradient(circle at 46% 66%, rgba(155, 229, 100, .16), transparent 38%),
    radial-gradient(circle at 68% 38%, rgba(255, 122, 26, .2), transparent 36%),
    radial-gradient(circle at 86% 60%, rgba(88, 118, 106, .28), transparent 34%);
}

.page-about .coverage__stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
}

.page-about .coverage__stat {
  background: var(--panel);
  padding: 1rem .85rem;
  display: flex;
  flex-direction: column;
  gap: .3rem;
}

.page-about .coverage__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.6rem;
  font-weight: 700;
  line-height: 1;
  color: var(--cream);
  letter-spacing: -0.02em;
}

.page-about .coverage__unit {
  font-size: .76rem;
  line-height: 1.5;
  color: var(--stone);
}

.page-about .support-list {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
}

.page-about .support-list li {
  position: relative;
  padding: .75rem 0 .75rem 1.4rem;
  border-bottom: var(--about-rule);
  font-size: .9rem;
  line-height: 1.8;
  color: var(--stone);
}

.page-about .support-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.45rem;
  width: 10px;
  height: 1px;
  background: var(--lime);
}

/* ---------- 末段呼吸区 ---------- */
.page-about .about-section--end {
  background: var(--panel);
  border: var(--about-rule);
  border-top: 1px solid var(--lime);
  padding: 1.75rem 1.15rem 1.5rem;
}

.page-about .about-section--end .about-section__title {
  max-width: 18ch;
}

.page-about .next-links {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: var(--about-rule);
  margin: 1.5rem 0 1rem;
}

.page-about .next-links__item {
  display: flex;
  flex-direction: column;
  gap: .35rem;
  padding: 1rem .9rem;
  background: var(--ink);
  text-decoration: none;
  transition: background var(--ease);
}

.page-about .next-links__item:hover,
.page-about .next-links__item:focus-visible {
  background: #10291F;
}

.page-about .next-links__label {
  font-size: 1rem;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--lime);
}

.page-about .next-links__item:hover .next-links__label,
.page-about .next-links__item:focus-visible .next-links__label {
  color: var(--signal);
}

.page-about .next-links__desc {
  font-size: .82rem;
  line-height: 1.65;
  color: var(--stone);
}

.page-about .next-links__foot {
  font-size: .85rem;
  line-height: 1.8;
  color: var(--stone);
  margin: 0;
}

.page-about .next-links__foot a {
  color: var(--cream);
  text-decoration: none;
  border-bottom: 1px solid var(--lime);
  transition: color var(--ease);
}

.page-about .next-links__foot a:hover,
.page-about .next-links__foot a:focus-visible {
  color: var(--lime);
}

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

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .container {
    padding-left: 40px;
    padding-right: 40px;
  }

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

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

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

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

  .page-about .roster__row {
    grid-template-columns: 7rem minmax(0, 1fr);
    gap: 1rem;
    align-items: baseline;
  }

  .page-about .about-section--end {
    padding: 2.25rem 1.75rem 1.75rem;
  }
}

@media (min-width: 900px) {
  .page-about .container {
    padding-left: 72px;
    padding-right: 72px;
  }

  .page-about .about-intro {
    padding: 3.5rem 0 2.75rem;
  }

  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 4rem;
    padding-top: 3rem;
  }

  .page-about .about-body {
    gap: 4rem;
  }

  .page-about .about-rail {
    position: sticky;
    top: 96px;
    align-self: start;
    border-bottom: 0;
    border-left: 1px solid var(--line);
    padding: 0 0 0 1rem;
    gap: 1.75rem;
  }

  .page-about .about-rail__years,
  .page-about .about-rail__nav {
    flex-direction: column;
    gap: .3rem;
    overflow-x: visible;
  }

  .page-about .about-rail__year {
    border: 0;
    border-radius: 0;
    padding: .3rem 0;
    justify-content: flex-start;
  }

  .page-about .about-rail__nav a {
    border-left: 1px solid var(--line);
    padding: .28rem 0 .28rem .7rem;
    display: block;
  }

  .page-about .about-rail__nav a:hover,
  .page-about .about-rail__nav a:focus-visible,
  .page-about .about-rail__nav a[aria-current="true"] {
    border-left-color: var(--lime);
  }

  .page-about .release {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    gap: 2.5rem;
  }

  .page-about .timeline__year {
    font-size: 1.75rem;
  }

  .page-about .about-figure {
    margin-top: 2.25rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition: none !important;
    animation: none !important;
  }
}