.page-about {
  --about-axis-x: 11px;
  --about-pad: 2.5rem;
  background: var(--snow);
  color: var(--deep);
  font-family: var(--font-body);
}

.page-about .section {
  padding-block: clamp(1.75rem, 4.5vw, 3.25rem);
}

.page-about .section__head {
  margin-bottom: clamp(1.25rem, 3vw, 2rem);
}

.page-about .section__title {
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -.01em;
  line-height: 1.25;
  font-size: clamp(1.5rem, 4.4vw, 2rem);
  color: var(--deep);
  margin: .35rem 0 0;
}

.page-about .section__lead {
  margin: .6rem 0 0;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--rock);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding-top: clamp(1.25rem, 3vw, 2rem);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -.02em;
  line-height: 1.04;
  font-size: clamp(2.1rem, 8.4vw, 5.4rem);
  color: var(--deep);
  margin: .35rem 0 1rem;
}

.page-about .about-hero__intro {
  font-size: 1.0625rem;
  line-height: 1.9;
  color: var(--deep);
  max-width: 48ch;
  margin: 0 0 1rem;
}

.page-about .about-hero__meta {
  display: inline-block;
  padding-top: .6rem;
  border-top: 1px solid var(--line);
  color: var(--rock);
}

.page-about .about-hero__note {
  border-top: 1px solid var(--line);
  padding-top: 1rem;
}

.page-about .about-hero__note .media {
  margin: 0 0 .85rem;
}

.page-about .about-hero__coord {
  display: block;
  font-family: var(--font-num);
  color: var(--sky);
  margin: 0 0 .5rem;
}

.page-about .about-hero__note-text {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--deep);
}

/* ---------- 天际线分隔 ---------- */

.page-about .about-ridge {
  line-height: 0;
  margin: clamp(1rem, 3vw, 2rem) 0;
}

.page-about .about-ridge svg {
  display: block;
  width: 100%;
  height: clamp(46px, 8vw, 92px);
}

.page-about .about-ridge path {
  fill: var(--mist);
}

.page-about .about-ridge .about-ridge__line {
  fill: none;
  stroke: var(--line);
  stroke-width: 1;
  vector-effect: non-scaling-stroke;
}

/* ---------- 专注方向 ---------- */

.page-about .about-focus__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-focus__body p {
  margin: 0 0 1.2em;
  font-size: 1.0625rem;
  line-height: 1.9;
}

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

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

.page-about .about-lines__item {
  position: relative;
  padding: 1rem .35rem 1rem 1.15rem;
  border-bottom: 1px solid var(--line);
}

.page-about .about-lines__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--accent, var(--sky));
  transition: width 180ms var(--ease);
}

.page-about .about-lines__item:hover::before,
.page-about .about-lines__item:focus-within::before {
  width: 6px;
}

.page-about .about-lines__item--live {
  --accent: var(--red);
}

.page-about .about-lines__item--report {
  --accent: var(--sky);
}

.page-about .about-lines__item--data {
  --accent: var(--green);
}

.page-about .about-lines__idx {
  display: block;
  font-size: .75rem;
  letter-spacing: .1em;
  color: var(--rock);
}

.page-about .about-lines__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.25rem;
  line-height: 1.25;
  color: var(--deep);
  margin: .3rem 0 .35rem;
}

.page-about .about-lines__item p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--deep);
}

/* ---------- 演进时间轴 ---------- */

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

.page-about .about-axis::before {
  content: "";
  position: absolute;
  left: var(--about-axis-x);
  top: .9rem;
  bottom: .9rem;
  width: 1px;
  background: var(--line);
}

.page-about .about-axis__node {
  position: relative;
  padding: 0 0 2.25rem var(--about-pad);
}

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

.page-about .about-axis__dot {
  position: absolute;
  left: var(--about-axis-x);
  top: .55rem;
  width: 11px;
  height: 11px;
  transform: translateX(-50%);
  border: 1px solid var(--rock);
  border-radius: 50%;
  background: var(--snow);
  transition: background-color 240ms var(--ease), border-color 240ms var(--ease), box-shadow 240ms var(--ease);
}

.page-about .about-axis__dot--old {
  width: 9px;
  height: 9px;
}

.page-about .about-axis__dot--mid {
  width: 13px;
  height: 13px;
}

.page-about .about-axis__dot--now {
  width: 17px;
  height: 17px;
  border-color: var(--sky);
  background: var(--mist);
}

.page-about .about-axis.is-visible .about-axis__dot {
  background: var(--sky);
  border-color: var(--sky);
  box-shadow: 0 0 0 4px rgba(10, 132, 255, .14);
}

.page-about .about-axis.is-visible .about-axis__node:nth-child(1) .about-axis__dot {
  transition-delay: 0ms;
}

.page-about .about-axis.is-visible .about-axis__node:nth-child(2) .about-axis__dot {
  transition-delay: 120ms;
}

.page-about .about-axis.is-visible .about-axis__node:nth-child(3) .about-axis__dot {
  transition-delay: 240ms;
}

.page-about .about-axis.is-visible .about-axis__node:nth-child(4) .about-axis__dot {
  transition-delay: 360ms;
}

.page-about .about-axis.is-visible .about-axis__node:nth-child(5) .about-axis__dot {
  transition-delay: 480ms;
}

.page-about .about-axis__year {
  margin: 0 0 .3rem;
  font-size: 1.375rem;
  letter-spacing: .02em;
  color: var(--sky);
}

.page-about .about-axis__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.1875rem;
  line-height: 1.3;
  color: var(--deep);
  margin: 0 0 .4rem;
}

.page-about .about-axis__body p {
  margin: 0;
  font-size: 1rem;
  line-height: 1.9;
  max-width: 62ch;
}

/* ---------- 内容与数据团队 ---------- */

.page-about .about-team__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.25rem, 3.5vw, 2rem);
}

.page-about .about-team__body p {
  margin: 0 0 1.2em;
  font-size: 1.0625rem;
  line-height: 1.9;
}

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

.page-about .about-team__figure {
  margin: 0;
}

.page-about .about-team__figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin-top: clamp(1.5rem, 4vw, 2.5rem);
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
}

.page-about .about-figure__value {
  display: flex;
  align-items: baseline;
  gap: .3rem;
  margin: 0 0 .4rem;
}

.page-about .about-figure__num {
  font-size: clamp(2rem, 5.4vw, 3.125rem);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--sky);
}

.page-about .about-figure__unit {
  font-size: .875rem;
  color: var(--rock);
}

/* ---------- 高原访问节点 ---------- */

.page-about .about-nodes__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-nodes__figure {
  margin: 0;
}

.page-about .about-nodes__lead {
  margin: 0 0 1.25rem;
  font-size: 1.0625rem;
  line-height: 1.9;
}

.page-about .about-nodes__map {
  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-nodes__item {
  position: relative;
  background: var(--snow);
  padding: .85rem .9rem .85rem 1.85rem;
  transition: background-color 200ms var(--ease);
}

.page-about .about-nodes__item::before {
  content: "";
  position: absolute;
  left: .75rem;
  top: 1.15rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--sky);
  transition: transform 200ms var(--ease);
}

.page-about .about-nodes__item:hover,
.page-about .about-nodes__item:focus-visible {
  background: var(--mist);
  outline: none;
}

.page-about .about-nodes__item:focus-visible {
  box-shadow: inset 0 0 0 2px var(--yellow);
}

.page-about .about-nodes__item:hover::before,
.page-about .about-nodes__item:focus-visible::before {
  transform: scale(1.5);
}

.page-about .about-nodes__city {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1rem;
  color: var(--deep);
}

.page-about .about-nodes__role {
  display: block;
  margin-top: .15rem;
  font-size: .875rem;
  line-height: 1.7;
  color: var(--rock);
}

.page-about .about-nodes__note {
  margin: 1.25rem 0 0;
  padding-left: .9rem;
  border-left: 2px solid var(--grid, var(--line));
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--deep);
}

/* ---------- 覆盖范围 ---------- */

.page-about .about-scope__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-sports {
  list-style: none;
  margin: .75rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-sports li {
  background: var(--snow);
  padding: .75rem .4rem;
  text-align: center;
  font-size: .9375rem;
  color: var(--deep);
  transition: background-color 180ms var(--ease), color 180ms var(--ease);
}

.page-about .about-sports li:hover {
  background: var(--mist);
  color: var(--indigo);
}

.page-about .about-scope__partner p {
  margin: 0 0 1.2em;
  font-size: 1.0625rem;
  line-height: 1.9;
}

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

/* ---------- 行业认可 ---------- */

.page-about .about-recognition__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.25rem;
  padding: clamp(1.25rem, 4vw, 2.25rem);
  background: var(--mist);
  border-left: 3px solid var(--sky);
}

.page-about .about-recognition__body p {
  margin: 0 0 1.2em;
  font-size: 1.0625rem;
  line-height: 1.9;
}

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

/* ---------- 收束 ---------- */

.page-about .about-close {
  background: var(--deep);
  color: var(--snow);
  margin-top: clamp(1.5rem, 4vw, 2.5rem);
  padding-block: clamp(2.5rem, 6vw, 4rem);
}

.page-about .about-close .section__kicker {
  color: var(--sky);
}

.page-about .about-close__title {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -.02em;
  line-height: 1.1;
  font-size: clamp(1.75rem, 5.4vw, 2.75rem);
  color: var(--snow);
  margin: .4rem 0 1rem;
}

.page-about .about-close__text {
  margin: 0 0 1.5rem;
  max-width: 60ch;
  font-size: 1.0625rem;
  line-height: 1.9;
  color: rgba(245, 248, 252, .86);
}

.page-about .about-close__links {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
}

.page-about .about-close .btn--ghost {
  color: var(--snow);
  border-color: rgba(245, 248, 252, .42);
}

.page-about .about-close .btn--ghost:hover {
  border-color: var(--snow);
  background: rgba(245, 248, 252, .08);
}

/* ---------- 响应式 ---------- */

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

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

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

  .page-about .about-axis__node {
    display: grid;
    grid-template-columns: 5.5rem minmax(0, 1fr);
    align-items: start;
    column-gap: 1rem;
  }

  .page-about .about-axis__year {
    grid-column: 1;
    text-align: left;
    margin: 0;
    padding-top: .1rem;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(2rem, 5vw, 4rem);
    align-items: end;
  }

  .page-about .about-focus__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .about-nodes__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .about-scope__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

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

  .page-about .about-recognition__inner {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    gap: clamp(1.5rem, 4vw, 3rem);
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .page-about .about-sports {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-axis__dot,
  .page-about .about-lines__item::before,
  .page-about .about-nodes__item,
  .page-about .about-nodes__item::before,
  .page-about .about-sports li {
    transition: none;
  }
}

.page-about {
  --grid: currentColor;
}