.page-about {
  --about-max: 1120px;
  --about-track-x: 10px;
  --about-node-size: 18px;
  position: relative;
  padding: 20px 18px 64px;
  color: var(--ink);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

.page-about > * {
  width: 100%;
  max-width: var(--about-max);
  margin-inline: auto;
}

/* ---------- 面包屑上下文 ---------- */

.page-about .breadcrumbs {
  margin-bottom: 22px;
}

/* ---------- 首屏 ---------- */

.about-hero {
  padding-bottom: 30px;
  border-bottom: 1px solid var(--line);
}

.about-hero__kicker {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--gold);
}

.about-hero h1 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: clamp(28px, 6.2vw, 44px);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -.02em;
  color: var(--ink);
}

.about-hero__lede {
  margin: 0 0 28px;
  max-width: 66ch;
  font-size: 15.5px;
  line-height: 1.82;
  color: var(--ink-2);
}

.about-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px 34px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.about-hero__meta li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 96px;
}

.about-hero__num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -.01em;
  color: var(--cyan);
}

.about-hero__unit {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--ink-3);
}

/* ---------- 通用板块 ---------- */

.about-section {
  margin-top: 56px;
}

.about-section__head {
  margin-bottom: 26px;
}

.about-section__index {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--gold);
}

.about-section__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: clamp(21px, 4.4vw, 30px);
  font-weight: 900;
  line-height: 1.3;
  letter-spacing: -.02em;
  color: var(--ink);
}

.about-section__intro {
  margin: 0;
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-2);
}

/* ---------- 图片 ---------- */

.about-figure {
  margin: 0 0 24px;
  background: var(--bg-panel);
  border: 1px solid var(--line);
}

.about-figure__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  background: var(--bg-deep);
}

.about-figure--banner .about-figure__img {
  aspect-ratio: 16 / 9;
}

.about-figure--land .about-figure__img {
  aspect-ratio: 3 / 2;
}

.about-figure--port .about-figure__img {
  aspect-ratio: 4 / 3;
}

.about-figure__cap {
  display: block;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.6;
  letter-spacing: .05em;
  color: var(--ink-3);
  background: var(--bg-deep);
  border-top: 1px solid var(--line);
}

/* ---------- 沿革时间线 ---------- */

.about-timeline {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.about-timeline::before {
  content: "";
  position: absolute;
  left: var(--about-track-x);
  top: 14px;
  bottom: 14px;
  width: 2px;
  background: linear-gradient(180deg, var(--violet) 0%, var(--line) 46%, var(--cyan) 100%);
  opacity: .55;
}

.about-node {
  position: relative;
  padding-left: 38px;
  margin-bottom: 22px;
}

.about-node:last-child {
  margin-bottom: 0;
}

.about-node::before {
  content: "";
  position: absolute;
  left: calc(var(--about-track-x) - var(--about-node-size) / 2 + 1px);
  top: 8px;
  width: var(--about-node-size);
  height: var(--about-node-size);
  background: var(--bg-deep);
  border: 2px solid var(--violet);
  transform: rotate(45deg);
  transition: border-color 200ms var(--ease), background-color 200ms var(--ease);
}

.about-node--current::before {
  border-color: var(--gold);
  background: rgba(231, 180, 76, .12);
}

.about-node__inner {
  padding: 16px 18px 18px;
  background: var(--bg-panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--line);
  transition: transform 200ms var(--ease), border-color 200ms var(--ease);
}

.about-node--current .about-node__inner {
  border-left-color: var(--gold);
}

.about-node:hover .about-node__inner {
  transform: translateY(-4px);
  border-color: rgba(53, 224, 214, .42);
}

.about-node__ver {
  display: inline-block;
  margin-bottom: 10px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--violet);
  border: 1px solid rgba(124, 107, 255, .45);
}

.about-node--current .about-node__ver {
  color: var(--gold);
  border-color: rgba(231, 180, 76, .5);
}

.about-node__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 17.5px;
  font-weight: 800;
  line-height: 1.42;
  letter-spacing: -.01em;
  color: var(--ink);
}

.about-node__text {
  margin: 0 0 14px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-2);
}

.about-node__point {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px 12px;
  margin: 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--ink-3);
}

.about-node__num {
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--cyan);
}

/* ---------- 双栏 ---------- */

.about-cols {
  display: grid;
  gap: 26px;
}

.about-cols__main {
  min-width: 0;
}

/* ---------- 口径词条 ---------- */

.about-glossary {
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.about-glossary__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 15px 0;
  border-bottom: 1px solid var(--line-soft);
}

.about-glossary dt {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--cyan);
}

.about-glossary dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ink-2);
}

/* ---------- 说明牌侧栏 ---------- */

.about-side {
  padding: 18px 18px 20px;
  background:
    linear-gradient(180deg, rgba(124, 107, 255, .1), rgba(124, 107, 255, 0) 62%),
    var(--bg-panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--violet);
}

.about-side--media {
  padding: 0;
  background: var(--bg-panel);
  border-left: 1px solid var(--line);
  border-top: 3px solid var(--violet);
}

.about-side--media .about-figure {
  margin: 0;
  border: 0;
}

.about-side__label {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--gold);
}

.about-side__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 800;
  line-height: 1.4;
  letter-spacing: -.01em;
  color: var(--ink);
}

.about-side__text {
  margin: 0 0 12px;
  font-size: 13.5px;
  line-height: 1.78;
  color: var(--ink-2);
}

.about-side__text:last-child {
  margin-bottom: 0;
  color: var(--ink-3);
}

/* ---------- 名录数据行 ---------- */

.about-datasets {
  margin: 0 0 20px;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.about-datasets__item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line-soft);
}

.about-datasets__key {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--ink-3);
}

.about-datasets__val {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--ink);
}

.about-note {
  margin: 0;
  padding: 14px 16px;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--ink-2);
  background: var(--bg-zebra);
  border-left: 3px solid var(--cyan);
}

/* ---------- 流程步骤 ---------- */

.about-steps {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: about-step;
}

.about-step {
  position: relative;
  counter-increment: about-step;
  margin-bottom: 12px;
  padding: 16px 18px 16px 58px;
  background: var(--bg-panel);
  border: 1px solid var(--line);
  transition: transform 200ms var(--ease), border-color 200ms var(--ease);
}

.about-step:last-child {
  margin-bottom: 0;
}

.about-step:hover {
  transform: translateY(-4px);
  border-color: rgba(53, 224, 214, .42);
}

.about-step::before {
  content: counter(about-step, decimal-leading-zero);
  position: absolute;
  left: 18px;
  top: 17px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--gold);
}

.about-step__title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 15.5px;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--ink);
}

.about-step__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ink-2);
}

/* ---------- 团队 ---------- */

.about-team {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 0 0 24px;
  padding: 0;
  list-style: none;
}

.about-team__cell {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 16px 18px;
  background: var(--bg-panel);
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan);
}

.about-team__num {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -.02em;
  color: var(--ink);
}

.about-team__cap {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--ink-3);
}

.about-prose p {
  margin: 0 0 14px;
  max-width: 72ch;
  font-size: 14.5px;
  line-height: 1.82;
  color: var(--ink-2);
}

.about-prose p:last-child {
  margin-bottom: 0;
}

/* ---------- 栏目分工 ---------- */

.about-split {
  display: grid;
  gap: 12px;
  margin-bottom: 24px;
}

.about-split__item {
  position: relative;
  padding: 18px 18px 20px;
  background: var(--bg-panel);
  border: 1px solid var(--line);
  transition: transform 200ms var(--ease), border-color 200ms var(--ease);
}

.about-split__item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 36px;
  height: 2px;
  background: var(--gold);
}

.about-split__item:hover {
  transform: translateY(-4px);
  border-color: rgba(53, 224, 214, .42);
}

.about-split__title {
  margin: 6px 0 8px;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--ink);
}

.about-split__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ink-2);
}

.about-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 224, 214, .35);
  transition: border-color 160ms var(--ease), color 160ms var(--ease);
}

.about-link:hover {
  color: var(--ink);
  border-bottom-color: var(--cyan);
}

.about-link:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
}

/* ---------- 断点 ---------- */

@media (min-width: 720px) {
  .page-about {
    padding: 30px 28px 88px;
  }

  .about-hero {
    padding-bottom: 38px;
  }

  .about-section {
    margin-top: 76px;
  }

  .about-glossary__row {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 6px 22px;
    align-items: baseline;
  }

  .about-datasets__item {
    grid-template-columns: 140px minmax(0, 1fr);
    gap: 4px 20px;
    align-items: baseline;
  }

  .about-team {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px;
  }

  .about-split {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }
}

@media (min-width: 1000px) {
  .page-about {
    padding: 42px 44px 112px;
  }

  .about-cols {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 44px;
    align-items: start;
  }

  .about-cols--flip {
    grid-template-columns: minmax(0, 1fr) 320px;
  }

  .about-node {
    padding-left: 42px;
  }

  .about-node__inner {
    padding: 20px 22px 22px;
  }

  .about-node__text {
    font-size: 15px;
  }

  .about-side {
    position: sticky;
    top: calc(var(--anchor-h) + 20px);
  }

  .about-side--media {
    position: static;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-node:hover .about-node__inner,
  .page-about .about-step:hover,
  .page-about .about-split__item:hover {
    transform: none;
  }
}
</main>