.page-about {
  --about-rail: 208px;
  --about-grid: rgba(23, 35, 58, 0.42);
  --about-card-hover: #0C1A2E;
  position: relative;
  color: var(--text);
  background-color: var(--ink);
  background-image:
    linear-gradient(to right, var(--about-grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--about-grid) 1px, transparent 1px);
  background-size: 48px 48px;
  background-position: center top;
  padding-bottom: clamp(64px, 9vw, 132px);
}

.page-about .about-crumb {
  padding-top: clamp(18px, 3vw, 36px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(22px, 4vw, 48px) 0 clamp(28px, 4vw, 52px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero-kicker {
  color: var(--live);
  margin: 0 0 clamp(14px, 2vw, 24px);
}

.page-about .about-hero-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 250;
  font-size: clamp(38px, 7.6vw, 104px);
  line-height: 1.03;
  letter-spacing: -0.03em;
  max-width: 16ch;
  color: var(--text);
}

.page-about .about-hero-cols {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  margin-top: clamp(26px, 4vw, 48px);
}

.page-about .about-hero-lede {
  margin: 0;
  max-width: 34em;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-hero-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-hero-facts li {
  background: var(--panel);
  padding: 14px 18px;
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-fact-num {
  font-size: 24px;
  color: var(--live);
  min-width: 84px;
}

.page-about .about-fact-label {
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.04em;
}

/* ---------- 首屏横幅 ---------- */
.page-about .about-banner {
  position: relative;
  margin: clamp(28px, 4vw, 56px) 0 0;
  border: 1px solid var(--line);
}

.page-about .about-banner::before,
.page-about .about-banner::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border: 1px solid var(--live);
  pointer-events: none;
}

.page-about .about-banner::before {
  top: -1px;
  left: -1px;
  border-right: 0;
  border-bottom: 0;
}

.page-about .about-banner::after {
  bottom: -1px;
  right: -1px;
  border-left: 0;
  border-top: 0;
}

.page-about .about-banner img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
  filter: saturate(0.92) contrast(1.06);
}

/* ---------- 主体双栏 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
  padding-top: clamp(44px, 7vw, 92px);
}

.page-about .about-index-title {
  margin: 0 0 12px;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-index-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
}

.page-about .about-index-list a {
  display: block;
  padding: 6px 0;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  color: var(--text);
}

.page-about .about-index-list a[aria-current]:not([aria-current="false"]) {
  color: var(--live);
  border-bottom-color: var(--live);
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding: clamp(44px, 6.4vw, 88px) 0;
  border-top: 1px solid var(--line);
}

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

.page-about .about-head {
  max-width: 46em;
}

.page-about .about-h2 {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(26px, 4.2vw, 54px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  max-width: 20ch;
}

.page-about .about-lead {
  margin: 16px 0 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: clamp(30px, 4.4vw, 54px) 0 0;
  padding: 0 0 0 22px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: var(--line);
}

.page-about .about-tl-item {
  position: relative;
  display: grid;
  gap: 6px;
  padding-bottom: clamp(22px, 3vw, 34px);
}

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: -22px;
  top: 8px;
  width: 7px;
  height: 7px;
  background: var(--live);
}

.page-about .about-tl-year {
  font-size: 19px;
  color: var(--live);
  letter-spacing: 0.02em;
}

.page-about .about-tl-body h3 {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 500;
  color: var(--text);
}

.page-about .about-tl-body p {
  margin: 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
  margin-top: clamp(30px, 4.4vw, 52px);
}

.page-about .about-team-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-team-list li {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 16px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
}

.page-about .about-team-list li:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .about-team-icon {
  display: block;
  color: var(--blue);
  padding-top: 2px;
}

.page-about .about-team-list h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 500;
}

.page-about .about-team-list p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-team-media {
  margin: 0;
  border: 1px solid var(--line);
}

.page-about .about-team-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  filter: saturate(0.85) contrast(1.05);
}

.page-about .about-team-media figcaption {
  padding: 14px 18px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

/* ---------- 数据来源 ---------- */
.page-about .about-sources {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
  margin-top: clamp(30px, 4.4vw, 52px);
}

.page-about .about-sources-media {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel);
}

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

.page-about .about-sources-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-sources-list li {
  padding: 20px 0;
  border-top: 1px solid var(--line);
}

.page-about .about-sources-list li:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .about-src-tag {
  display: inline-block;
  margin-bottom: 10px;
  padding: 2px 9px;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--blue);
  border: 1px solid var(--line);
}

.page-about .about-sources-list h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 500;
}

.page-about .about-sources-list p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 内容板块地图 ---------- */
.page-about .about-map {
  list-style: none;
  display: grid;
  gap: 1px;
  grid-template-columns: minmax(0, 1fr);
  margin: clamp(30px, 4.4vw, 52px) 0 0;
  padding: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-map-item {
  background: var(--panel);
  padding: clamp(20px, 2.6vw, 30px);
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: background 180ms var(--ease);
}

.page-about .about-map-item:hover {
  background: var(--hover-green);
}

.page-about .about-map-item h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 500;
}

.page-about .about-map-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
  flex: 1 1 auto;
}

.page-about .about-map-link {
  align-self: flex-start;
  margin-top: 4px;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--live);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  padding-bottom: 2px;
  transition: border-color 180ms var(--ease);
}

.page-about .about-map-link:hover,
.page-about .about-map-link:focus-visible {
  border-bottom-color: var(--live);
}

/* ---------- 版本记录 ---------- */
.page-about .about-filter {
  margin-top: clamp(26px, 3.6vw, 40px);
}

.page-about .about-versions {
  list-style: none;
  display: grid;
  gap: 1px;
  grid-template-columns: minmax(0, 1fr);
  margin: 22px 0 0;
  padding: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-version {
  position: relative;
  background: var(--panel);
  padding: 22px 22px 24px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: background 180ms var(--ease);
}

.page-about .about-version::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--blue);
  opacity: 0;
  transition: opacity 180ms var(--ease);
}

.page-about .about-version:hover,
.page-about .about-version:focus-within {
  background: var(--about-card-hover);
}

.page-about .about-version:hover::before,
.page-about .about-version:focus-within::before {
  opacity: 1;
}

.page-about .about-v-num {
  font-size: clamp(26px, 3vw, 34px);
  line-height: 1;
  color: var(--text);
  opacity: 0.26;
}

.page-about .about-v-year {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--alert);
}

.page-about .about-version h3 {
  margin: 4px 0 0;
  font-size: 16px;
  font-weight: 500;
}

.page-about .about-version p {
  margin: 0;
  font-size: 14px;
  line-height: 1.76;
  color: var(--muted);
}

.page-about .about-v-scope {
  margin-top: 10px;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--disabled);
}

.page-about .about-table-toggle {
  margin-top: 22px;
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .about-table-toggle > summary {
  cursor: pointer;
  list-style: none;
  padding: 16px 20px;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--blue);
}

.page-about .about-table-toggle > summary::-webkit-details-marker {
  display: none;
}

.page-about .about-table-toggle > summary::after {
  content: "+";
  float: right;
  color: var(--live);
}

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

.page-about .about-table-wrap {
  overflow-x: auto;
  border-top: 1px solid var(--line);
}

.page-about .about-table {
  width: 100%;
  min-width: 680px;
  border-collapse: collapse;
  font-size: 14px;
}

.page-about .about-table th,
.page-about .about-table td {
  text-align: left;
  padding: 13px 18px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
  white-space: nowrap;
}

.page-about .about-table thead th {
  font-family: var(--font-data);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.16em;
  color: var(--muted);
  text-transform: uppercase;
}

.page-about .about-table tbody th {
  font-family: var(--font-data);
  font-size: 13px;
  font-weight: 600;
  color: var(--live);
}

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

.page-about .about-table tbody tr:hover td,
.page-about .about-table tbody tr:hover th {
  background: rgba(15, 44, 36, 0.55);
  box-shadow: inset 2px 0 0 var(--blue);
}

/* ---------- 数据复查与合作 ---------- */
.page-about .about-section--quality {
  border-top: 1px solid var(--line);
}

.page-about .about-quality {
  display: grid;
  gap: clamp(32px, 4.6vw, 56px);
  margin-top: clamp(28px, 4vw, 48px);
}

.page-about .about-quality-num {
  margin: 0;
  font-size: clamp(62px, 12vw, 148px);
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: var(--live);
}

.page-about .about-quality-num span {
  font-size: 0.42em;
  letter-spacing: 0;
}

.page-about .about-quality-copy {
  margin: 20px 0 0;
  max-width: 32em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

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

.page-about .about-quality-list li {
  background: var(--panel);
  padding: 16px 18px;
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-q-num {
  font-size: 20px;
  color: var(--blue);
  min-width: 74px;
}

.page-about .about-q-label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .about-quality-foot {
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  max-width: 40em;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-quality-foot a {
  color: var(--live);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: border-color 180ms var(--ease);
}

.page-about .about-quality-foot a:hover,
.page-about .about-quality-foot a:focus-visible {
  border-bottom-color: var(--live);
}

/* ---------- 桌面布局 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero-cols {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-hero-facts li {
    padding: 16px 20px;
  }

  .page-about .about-tl-item {
    grid-template-columns: 112px minmax(0, 1fr);
    align-items: start;
    column-gap: 26px;
  }

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

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

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

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(44px, 5vw, 88px);
  }

  .page-about .about-index {
    position: sticky;
    top: 128px;
    align-self: start;
  }

  .page-about .about-index-list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-index-list a {
    padding: 9px 0 9px 16px;
    margin-left: -1px;
    border-bottom: 0;
    border-left: 2px solid transparent;
  }

  .page-about .about-index-list a[aria-current]:not([aria-current="false"]) {
    border-left-color: var(--live);
    border-bottom-color: transparent;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    gap: clamp(40px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-sources {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
    gap: clamp(40px, 5vw, 72px);
    align-items: center;
  }

  .page-about .about-quality {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    gap: clamp(44px, 5vw, 80px);
    align-items: end;
  }
}

@media (min-width: 1200px) {
  .page-about .about-map {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
  }
}