.page-about {
  --about-pad: 40px 0;
}

.page-about .about-scope {
  display: block;
  background-image:
    repeating-linear-gradient(90deg, transparent 0 46px, rgba(47, 93, 80, .045) 46px 47px),
    repeating-linear-gradient(0deg, transparent 0 46px, rgba(47, 93, 80, .045) 46px 47px);
}

.page-about .crumb {
  padding-top: 24px;
}

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

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  display: grid;
  gap: 16px;
  padding: 22px 0 30px;
  border-bottom: var(--edge);
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-weight: 900;
  letter-spacing: -0.02em;
  font-size: clamp(28px, 6.4vw, 52px);
  line-height: 1.15;
  color: var(--ink);
  margin: 0;
  max-width: 20ch;
}

.page-about .about-hero__lead {
  display: grid;
  gap: 12px;
  max-width: 46ch;
}

.page-about .about-hero__lead p {
  margin: 0;
  color: var(--ink);
  line-height: 1.75;
}

.page-about .about-hero__meta {
  border: var(--edge);
  background: var(--card);
  box-shadow: var(--shadow-sm);
  padding: 18px;
  display: grid;
  gap: 10px;
  align-content: start;
}

.page-about .about-hero__meta p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink);
}

.page-about .about-hero__lang {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
  border-top: 1px dashed var(--grid);
  padding-top: 10px;
}

/* ---------- 筛选条 ---------- */

.page-about .about-filterbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 16px;
  padding: 18px 0;
  border-bottom: 1px dashed var(--grid);
}

.page-about .about-filterbar__label {
  margin: 0;
  color: var(--muted);
}

.page-about .about-filterbar .filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-filterbar .filter-btn {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .02em;
}

/* ---------- 章节通用 ---------- */

.page-about .about-sec {
  position: relative;
  padding: var(--about-pad);
  border-bottom: 1px dashed var(--grid);
}

.page-about .about-sec:last-child {
  border-bottom: 0;
}

.page-about .about-sec__head {
  margin-bottom: 24px;
}

.page-about .about-sec__head h2 {
  font-family: var(--font-head);
  font-weight: 900;
  letter-spacing: -0.02em;
  font-size: clamp(22px, 4.4vw, 36px);
  line-height: 1.2;
  color: var(--ink);
  margin: 8px 0 0;
  max-width: 22ch;
}

.page-about .about-sec__lead {
  margin: 10px 0 0;
  max-width: 42ch;
  color: var(--muted);
  line-height: 1.75;
}

.page-about .about-lede {
  margin: 0 0 18px;
  max-width: 44ch;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .about-note {
  margin: 18px 0 0;
  padding-left: 14px;
  border-left: 3px solid var(--signal);
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 54ch;
}

.page-about .about-note a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--data);
  text-underline-offset: 3px;
}

/* ---------- 宽窄布局 ---------- */

.page-about .about-split {
  display: grid;
  gap: 24px;
}

.page-about .about-fig {
  margin: 0;
  border: var(--edge);
  background: var(--card);
  box-shadow: var(--shadow);
}

.page-about .about-fig .figure__media {
  border-bottom: var(--edge);
  object-fit: cover;
  width: 100%;
}

.page-about .about-fig .figure__cap {
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
  padding: 10px 14px;
}

/* ---------- 提供 / 不提供 ---------- */

.page-about .about-cols {
  display: grid;
  gap: 14px;
}

.page-about .about-cols__col {
  padding: 16px 16px 18px;
  border: 2px solid var(--ink);
}

.page-about .about-cols__col--yes {
  background: var(--cell);
}

.page-about .about-cols__col--no {
  background: var(--mist);
  border-style: dashed;
}

.page-about .about-cols__col h3 {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--ink);
  text-transform: uppercase;
}

.page-about .about-cols__col ul {
  margin: 0;
  padding-left: 1.1em;
  display: grid;
  gap: 8px;
}

.page-about .about-cols__col li {
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink);
}

.page-about .about-cols__col--no li {
  color: var(--muted);
}

/* ---------- 索引式清单 ---------- */

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

.page-about .about-index__row {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 12px;
  padding: 16px 2px;
  border-bottom: 1px solid var(--grid);
}

.page-about .about-index__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  color: var(--signal);
  padding-top: 4px;
}

.page-about .about-index__body h3 {
  margin: 0 0 6px;
  font-size: 17px;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .about-index__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .about-index__body a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--data);
  text-underline-offset: 3px;
}

/* ---------- 版本刻度 ---------- */

.page-about .about-timeline-box {
  margin-top: 32px;
  border: var(--edge);
  background: var(--card);
  box-shadow: var(--shadow-sm);
  padding: 18px 16px 10px;
}

.page-about .about-timeline-box h3 {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
  text-transform: uppercase;
}

.page-about .about-timeline {
  display: block;
  width: 100%;
  height: auto;
  margin-top: 6px;
}

.page-about .about-timeline .tl-axis {
  stroke: var(--bamboo);
  stroke-width: 2;
}

.page-about .about-timeline .tl-tick line {
  stroke: var(--ink);
  stroke-width: 2;
  transition: stroke .18s var(--ease);
}

.page-about .about-timeline .tl-tick:hover line {
  stroke: var(--signal);
}

.page-about .about-timeline .tl-tick:hover .tl-count {
  fill: var(--ink);
}

.page-about .about-timeline text {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  text-anchor: middle;
}

.page-about .about-timeline .tl-count {
  fill: var(--signal);
  font-size: 16px;
  transition: fill .18s var(--ease);
}

.page-about .about-timeline .tl-year {
  fill: var(--ink);
  font-size: 13px;
}

.page-about .about-timeline .tl-note {
  fill: var(--muted);
  font-size: 12px;
}

.page-about .about-timeline-note {
  margin: 4px 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
}

/* ---------- 数据模块 ---------- */

.page-about .about-fig--wide {
  margin: 0 0 24px;
}

.page-about .about-modules {
  margin-top: 4px;
}

.page-about .about-module {
  display: grid;
  gap: 10px;
  align-content: start;
  background: var(--card);
}

.page-about .about-module__top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.page-about .about-module h3 {
  margin: 2px 0 0;
  font-size: 19px;
  line-height: 1.35;
  color: var(--ink);
}

.page-about .about-module p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .about-module__metrics {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 2px;
}

.page-about .about-module__src {
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  border-top: 1px dashed var(--grid);
  padding-top: 10px;
}

.page-about .about-module__src a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--data);
  text-underline-offset: 3px;
}

.page-about .about-paths {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: var(--edge);
}

.page-about .about-paths li {
  display: grid;
  gap: 4px;
  padding: 14px 2px;
  border-bottom: 1px solid var(--grid);
}

.page-about .about-paths a {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 2px solid var(--signal);
  justify-self: start;
  padding-bottom: 2px;
}

.page-about .about-paths span {
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 团队 ---------- */

.page-about .about-team {
  display: grid;
  gap: 14px;
}

.page-about .about-team__card {
  border: var(--edge);
  background: var(--card);
  box-shadow: var(--shadow-xs);
  padding: 18px;
  display: grid;
  gap: 8px;
  align-content: start;
}

.page-about .about-team__card h3 {
  margin: 0;
  font-size: 18px;
  line-height: 1.35;
  color: var(--ink);
}

.page-about .about-team__card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .about-flow {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
  counter-reset: flow;
}

.page-about .about-flow li {
  position: relative;
  border: var(--edge);
  background: var(--haze);
  padding: 14px 16px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .02em;
  color: var(--ink);
}

/* ---------- 备案与联系 ---------- */

.page-about .about-records {
  margin: 0;
  border-top: var(--edge);
}

.page-about .about-records__row {
  display: grid;
  grid-template-columns: minmax(96px, 132px) minmax(0, 1fr);
  gap: 10px 16px;
  padding: 14px 2px;
  border-bottom: 1px solid var(--grid);
}

.page-about .about-records dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--muted);
  padding-top: 3px;
}

.page-about .about-records dd {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink);
  word-break: break-word;
}

.page-about .about-records__actions {
  margin: 22px 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 响应式 ---------- */

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

  .page-about .about-flow li::after {
    content: "";
  }
}

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

  .page-about .about-paths li {
    grid-template-columns: 200px minmax(0, 1fr);
    align-items: baseline;
    gap: 20px;
  }

  .page-about .about-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 30px;
  }

  .page-about .about-flow li:not(:last-child)::after {
    content: "→";
    position: absolute;
    right: -22px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--signal);
    font-size: 15px;
  }
}

@media (min-width: 900px) {
  .page-about {
    --about-pad: 56px 0;
  }

  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    column-gap: 48px;
    row-gap: 20px;
    padding: 30px 0 44px;
  }

  .page-about .about-hero > .kicker,
  .page-about .about-hero > h1 {
    grid-column: 1 / -1;
  }

  .page-about .about-hero__lead {
    grid-column: 1;
  }

  .page-about .about-hero__meta {
    grid-column: 2;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.95fr);
    column-gap: 44px;
    align-items: start;
  }

  .page-about .about-split--reverse {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  }

  .page-about .about-sec__lead {
    max-width: 46ch;
  }

  .page-about .about-index__row {
    grid-template-columns: 78px minmax(0, 1fr);
    gap: 20px;
    padding: 18px 4px;
  }

  .page-about .about-sec--narrow .about-sec__head,
  .page-about .about-sec--narrow .about-index {
    max-width: 860px;
  }

  .page-about .about-fig--side .figure__media {
    aspect-ratio: 4 / 3;
  }
}

@media (min-width: 1180px) {
  .page-about .about-hero {
    column-gap: 64px;
  }

  .page-about .about-lede {
    max-width: 40ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-timeline .tl-tick line,
  .page-about .about-timeline .tl-count {
    transition: none;
  }
}