.page-about {
  --ab-line: var(--ly-grid);
  --ab-rail-x: 12px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: 36px;
  padding: clamp(28px, 5vw, 60px) 0 clamp(48px, 7vw, 88px);
  border-bottom: 1px solid var(--ly-grid);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--ly-font-display);
  font-weight: 900;
  font-size: clamp(32px, 8vw, 64px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--ly-ink);
  max-width: 14em;
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 36em;
  font-size: 17px;
  line-height: 1.85;
  color: var(--ly-mist);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 32px 0 0;
  padding: 0;
  background: var(--ly-grid);
  border: 1px solid var(--ly-grid);
}

.page-about .about-hero__facts > div {
  background: var(--ly-abyss);
  padding: 14px 16px;
  min-width: 0;
}

.page-about .about-hero__facts dt {
  font-family: var(--ly-font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--ly-mist);
}

.page-about .about-hero__facts dd {
  margin: 8px 0 0;
  font-family: var(--ly-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 17px;
  line-height: 1.2;
  color: var(--ly-cyan);
  word-break: break-word;
}

.page-about .about-hero__figure {
  margin: 0;
  border: 1px solid var(--ly-grid);
  background: var(--ly-panel);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  filter: saturate(0.6) brightness(0.8) contrast(1.05);
}

.page-about .about-hero__figure figcaption {
  padding: 12px 16px;
  border-top: 1px solid var(--ly-grid);
  font-size: 12px;
  line-height: 1.7;
  color: var(--ly-mist);
}

/* ---------- 纵向时间线 ---------- */
.page-about .about-rail {
  position: relative;
  padding-top: clamp(48px, 7vw, 88px);
}

.page-about .about-rail::before {
  content: "";
  position: absolute;
  top: clamp(48px, 7vw, 88px);
  bottom: 0;
  left: var(--ab-rail-x);
  width: 1px;
  background: linear-gradient(180deg, var(--ab-line) 0%, var(--ab-line) 86%, rgba(23, 54, 79, 0) 100%);
}

.page-about .about-phase {
  position: relative;
  padding-left: 44px;
  padding-bottom: clamp(56px, 8vw, 104px);
}

.page-about .about-phase--last {
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .about-phase__node {
  position: absolute;
  left: 0;
  top: 0;
  width: 25px;
  height: 25px;
  display: grid;
  place-items: center;
  background: var(--ly-abyss);
  border: 1px solid var(--ly-grid);
  color: var(--ly-cyan);
  font-family: var(--ly-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 10px;
  letter-spacing: 0.02em;
  line-height: 1;
}

.page-about .about-phase__title {
  margin: 12px 0 0;
  font-family: var(--ly-font-display);
  font-weight: 800;
  font-size: clamp(24px, 5vw, 38px);
  line-height: 1.1;
  letter-spacing: -0.015em;
  color: var(--ly-ink);
  max-width: 18em;
}

.page-about .about-phase__body > .about-lead,
.page-about .about-phase__body > .about-close {
  margin: 24px 0 0;
  max-width: 36em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ly-ink);
}

.page-about .about-phase__body > .about-close {
  color: var(--ly-mist);
  padding-top: 20px;
  border-top: 1px solid var(--ly-grid);
}

.page-about .about-phase__body a {
  color: var(--ly-electric);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-phase__body a:hover,
.page-about .about-phase__body a:focus-visible {
  color: var(--ly-cyan);
}

/* ---------- 浅色阅读分区 ---------- */
.page-about .about-read {
  margin: 24px 0 0;
  padding: clamp(22px, 4vw, 36px);
  background: var(--ly-paper);
  color: var(--ly-paper-ink);
  max-width: 46em;
}

.page-about .about-read p {
  margin: 0;
  max-width: 36em;
  font-size: 16px;
  line-height: 1.85;
}

.page-about .about-read p + p {
  margin-top: 16px;
}

.page-about .about-read a {
  color: #0a4a8a;
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 横条图 ---------- */
.page-about .about-band {
  margin: 28px 0 0;
  border: 1px solid var(--ly-grid);
}

.page-about .about-band img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  filter: saturate(0.55) brightness(0.76) contrast(1.06);
}

/* ---------- 覆盖矩阵 ---------- */
.page-about .about-matrix {
  display: grid;
  gap: 24px;
  margin: 32px 0 0;
  padding: clamp(20px, 3.5vw, 32px);
  border: 1px solid var(--ly-grid);
  background: var(--ly-panel);
}

.page-about .about-matrix__svg {
  display: block;
  width: 100%;
  max-width: 260px;
  height: auto;
}

.page-about .about-matrix__legend {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-matrix__legend li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--ly-mist);
}

.page-about .about-matrix__dot {
  flex: none;
  width: 11px;
  height: 11px;
}

.page-about .about-matrix__dot--eu { background: var(--ly-cyan); }
.page-about .about-matrix__dot--as { background: var(--ly-electric); }
.page-about .about-matrix__dot--sa { background: var(--ly-coral); }
.page-about .about-matrix__dot--af { background: var(--ly-lemon); }
.page-about .about-matrix__dot--empty {
  background: var(--ly-abyss);
  border: 1px solid var(--ly-grid);
}

/* ---------- 可展开洲别 ---------- */
.page-about .about-zones {
  display: grid;
  gap: 1px;
  margin: 24px 0 0;
  background: var(--ly-grid);
  border: 1px solid var(--ly-grid);
}

.page-about .about-zone {
  background: var(--ly-panel);
}

.page-about .about-zone__sum {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 48px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
  font-family: var(--ly-font-display);
  font-weight: 700;
  font-size: 16px;
  color: var(--ly-ink);
}

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

.page-about .about-zone__sum::after {
  content: "+";
  margin-left: auto;
  font-family: var(--ly-font-mono);
  font-size: 16px;
  line-height: 1;
  color: var(--ly-cyan);
}

.page-about .about-zone[open] .about-zone__sum::after {
  content: "–";
}

.page-about .about-zone__sum:focus-visible {
  outline: 2px solid var(--ly-cyan);
  outline-offset: -2px;
}

.page-about .about-zone__name {
  letter-spacing: 0.02em;
}

.page-about .about-zone__count {
  font-size: 13px;
  color: var(--ly-cyan);
  border: 1px solid var(--ly-grid);
  padding: 3px 8px;
}

.page-about .about-zone__body {
  padding: 0 18px 18px;
  border-top: 1px solid var(--ly-grid);
}

.page-about .about-zone__body p {
  margin: 14px 0 0;
  max-width: 36em;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ly-mist);
}

/* ---------- 无序号列表与表格切换 ---------- */

/* ---------- 判定值定义 ---------- */
.page-about .about-split {
  display: grid;
  gap: 32px;
  margin-top: 24px;
}

.page-about .about-split__aside {
  margin: 0;
  border: 1px solid var(--ly-grid);
  align-self: start;
}

.page-about .about-split__aside img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  filter: saturate(0.6) brightness(0.78);
}

.page-about .about-split__aside figcaption {
  padding: 12px 14px;
  border-top: 1px solid var(--ly-grid);
  font-size: 12px;
  line-height: 1.7;
  color: var(--ly-mist);
}

.page-about .about-defs {
  margin: 28px 0 0;
  padding: 0;
  border-top: 1px solid var(--ly-grid);
}

.page-about .about-def {
  border-bottom: 1px solid var(--ly-grid);
  padding: 16px 0;
}

.page-about .about-def__term {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-family: var(--ly-font-display);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.3;
  color: var(--ly-ink);
}

.page-about .about-def__idx {
  font-size: 11px;
  color: var(--ly-cyan);
  border: 1px solid var(--ly-grid);
  padding: 2px 6px;
  flex: none;
}

.page-about .about-def__desc {
  margin: 10px 0 0;
}

.page-about .about-def__brief {
  margin: 0;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ly-mist);
}

.page-about .about-def__note {
  margin-top: 10px;
  border-left: 1px solid var(--ly-grid);
  padding-left: 14px;
}

.page-about .about-def__note .ly-details__body p {
  margin: 10px 0 0;
  max-width: 36em;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ly-mist);
}

/* ---------- 表格区 ---------- */
.page-about .about-table__wrap {
  margin-top: 26px;
  overflow-x: auto;
  border: 1px solid var(--ly-grid);
  background: var(--ly-panel);
}

.page-about .about-table {
  width: 100%;
  min-width: 480px;
  border-collapse: collapse;
  font-size: 14px;
}

.page-about .about-table th,
.page-about .about-table td {
  padding: 12px 16px 12px 8px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--ly-grid);
  line-height: 1.6;
}

.page-about .about-table th:first-child,
.page-about .about-table td:first-child {
  padding-left: 16px;
}

.page-about .about-table tbody tr:last-child th,
.page-about .about-table tbody tr:last-child td {
  border-bottom: 0;
}

.page-about .about-table thead th {
  font-family: var(--ly-font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.16em;
  color: var(--ly-mist);
  white-space: nowrap;
  border-bottom-color: var(--ly-cyan);
}

.page-about .about-table tbody th {
  font-weight: 600;
  color: var(--ly-ink);
  white-space: nowrap;
}

.page-about .about-table tbody td {
  color: var(--ly-mist);
}

.page-about .about-table td.ly-num {
  color: var(--ly-cyan);
  white-space: nowrap;
}

/* ---------- 版本迭代 ---------- */
.page-about .about-versions {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--ly-grid);
  border: 1px solid var(--ly-grid);
}

.page-about .about-ver {
  display: grid;
  gap: 8px;
  padding: 18px 20px;
  background: var(--ly-panel);
}

.page-about .about-ver__no {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ly-cyan);
}

.page-about .about-ver__title {
  margin: 0;
  font-family: var(--ly-font-display);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.3;
  color: var(--ly-ink);
}

.page-about .about-ver__text {
  margin: 0;
  max-width: 36em;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ly-mist);
}

.page-about .about-ver__text a {
  color: var(--ly-electric);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 地域与备案窄条 ---------- */
.page-about .about-meta {
  display: grid;
  gap: 1px;
  margin: 24px 0 0;
  background: var(--ly-grid);
  border: 1px solid var(--ly-grid);
}

.page-about .about-meta__item {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 18px;
  background: var(--ly-turf);
}

.page-about .about-meta__key {
  font-family: var(--ly-font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--ly-mist);
}

.page-about .about-meta__val {
  font-family: var(--ly-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 15px;
  color: var(--ly-ink);
}

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

  .page-about .about-matrix {
    grid-template-columns: minmax(0, 240px) minmax(0, 1fr);
    gap: 40px;
    align-items: center;
  }

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

  .page-about .about-def {
    display: grid;
    grid-template-columns: minmax(0, 200px) minmax(0, 1fr);
    gap: 24px;
    padding: 18px 0;
  }

  .page-about .about-def__desc {
    margin-top: 0;
  }

  .page-about .about-ver {
    grid-template-columns: 92px minmax(0, 190px) minmax(0, 1fr);
    align-items: baseline;
    gap: 22px;
  }

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

/* ---------- 桌面 ---------- */
@media (min-width: 1024px) {
  .page-about {
    --ab-rail-x: 18px;
  }

  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(36px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-phase {
    padding-left: 84px;
  }

  .page-about .about-phase__node {
    width: 37px;
    height: 37px;
    font-size: 12px;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 340px);
    gap: 48px;
    align-items: start;
  }

  .page-about .about-matrix {
    grid-template-columns: minmax(0, 280px) minmax(0, 1fr);
  }
}

@media (min-width: 1200px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 380px);
  }
}

/* ---------- 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-zone__sum,
  .page-about .about-phase__node {
    transition: none;
  }
}