.page-about {
  --about-rule: rgba(185, 191, 198, 0.16);
  --about-soft: rgba(34, 224, 208, 0.08);
  --about-pad: clamp(44px, 7vw, 96px);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(24px, 4vw, 48px) 0 clamp(48px, 8vw, 96px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -16%;
  right: -14%;
  width: min(780px, 92vw);
  height: min(580px, 76vw);
  background: linear-gradient(135deg, rgba(34, 224, 208, 0.15), rgba(11, 27, 43, 0) 62%);
  clip-path: polygon(22% 0, 100% 0, 100% 66%, 0 100%);
  z-index: -1;
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--line) 18%, var(--line) 82%, transparent);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(28px, 5vw, 56px);
}

.page-about .about-hero__title {
  margin: 0.4em 0 0.55em;
  font-weight: 250;
  letter-spacing: 0.035em;
  line-height: 1.06;
  font-size: clamp(36px, 7.4vw, 84px);
  color: var(--white);
}

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

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 32px);
}

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

.page-about .about-hero__stats li {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(16px, 2.4vw, 24px);
  background: linear-gradient(160deg, rgba(16, 38, 31, 0.92), rgba(11, 27, 43, 0.94));
}

.page-about .about-hero__stats .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 300;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .about-hero__stat-label {
  font-size: 12px;
  line-height: 1.65;
  letter-spacing: 0.05em;
  color: var(--muted);
}

/* ---------- 章节节奏 ---------- */

.page-about .section {
  padding-top: var(--about-pad);
  padding-bottom: var(--about-pad);
}

.page-about .eyebrow {
  margin-bottom: 12px;
}

.page-about .h2 {
  margin-bottom: clamp(16px, 2.4vw, 26px);
}

.page-about p {
  color: var(--text);
}

/* ---------- 品牌起点 ---------- */

.page-about .about-origin {
  align-items: start;
}

.page-about .about-origin__text p + p {
  margin-top: 1.2em;
}

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

.page-about .about-origin__figure img {
  border: 1px solid var(--about-rule);
}

/* ---------- 数据处理 ---------- */

.page-about .about-review {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
}

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

.page-about .about-steps {
  list-style: none;
  counter-reset: about-step;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-steps li {
  position: relative;
  padding: 20px 20px 20px 62px;
  background: var(--ink);
  transition: background var(--dur) var(--ease);
}

.page-about .about-steps li::before {
  counter-increment: about-step;
  content: counter(about-step, decimal-leading-zero);
  position: absolute;
  left: 22px;
  top: 21px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .about-steps li:hover {
  background: var(--glass);
}

.page-about .about-steps strong {
  display: block;
  margin-bottom: 6px;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--white);
}

.page-about .about-steps span {
  display: block;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-steps a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 224, 208, 0.35);
}

.page-about .about-steps a:hover {
  border-bottom-color: var(--cyan);
}

/* ---------- 版本时间线 ---------- */

.page-about .about-versions__grid {
  display: grid;
  gap: clamp(28px, 5vw, 48px);
  align-items: start;
  margin-top: clamp(24px, 4vw, 40px);
}

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

.page-about .arc-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--line) 32%, var(--line));
}

.page-about .arc-node {
  position: relative;
  padding: 0 0 30px 36px;
  outline: none;
}

.page-about .arc-node:last-child {
  padding-bottom: 4px;
}

.page-about .arc-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 5px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--amber);
  box-shadow: 0 0 0 4px rgba(255, 162, 58, 0.1);
}

.page-about .arc-node:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 6px;
}

.page-about .arc-node__year {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .arc-node__body h3 {
  margin: 0 0 8px;
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 400;
  letter-spacing: 0.02em;
  color: var(--white);
}

.page-about .arc-node__body p {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.85;
}

.page-about .arc-node__more {
  max-height: 0;
  margin: 0;
  padding: 0 0 0 12px;
  overflow: hidden;
  opacity: 0;
  border-left: 1px solid var(--about-rule);
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
  transition: max-height var(--dur) var(--ease), opacity var(--dur) var(--ease),
    margin var(--dur) var(--ease), padding var(--dur) var(--ease);
}

@media (hover: hover) {
  .page-about .arc-node:hover .arc-node__more {
    max-height: 200px;
    margin-top: 6px;
    opacity: 1;
  }
}

.page-about .arc-node:focus .arc-node__more,
.page-about .arc-node:focus-within .arc-node__more {
  max-height: 200px;
  margin-top: 6px;
  opacity: 1;
}

.page-about .arc-node .tag {
  display: inline-block;
  margin-bottom: 2px;
}

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

.page-about .about-versions__figure img {
  border: 1px solid var(--about-rule);
}

/* ---------- 团队分工 ---------- */

.page-about .crew-grid {
  display: grid;
  gap: 1px;
  margin-top: clamp(24px, 4vw, 40px);
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .crew-card {
  position: relative;
  padding: clamp(22px, 3vw, 32px);
  background: var(--ink);
  transition: background var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .crew-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 2px;
  background: var(--line);
  transition: background var(--dur) var(--ease);
}

.page-about .crew-card:hover {
  background: var(--glass);
  transform: translateY(-2px);
}

.page-about .crew-card:hover::before {
  background: var(--cyan);
}

.page-about .crew-card__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.page-about .crew-card__head h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 400;
  letter-spacing: 0.05em;
  color: var(--white);
}

.page-about .crew-card__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--muted);
}

.page-about .crew-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 服务地区 ---------- */

.page-about .about-region {
  display: grid;
  gap: clamp(26px, 4vw, 44px);
  align-items: start;
}

.page-about .about-region__lead p + p {
  margin-top: 1.2em;
}

.page-about .about-region__panel {
  padding: clamp(20px, 3vw, 28px);
  border: 1px solid var(--about-rule);
  background: linear-gradient(155deg, rgba(16, 38, 31, 0.7), rgba(11, 27, 43, 0.7));
}

.page-about .about-region__panel-label {
  margin: 0 0 16px;
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--muted);
  text-transform: uppercase;
}

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

.page-about .about-region__cities li {
  padding: 6px 12px;
  border: 1px solid var(--line);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--silver);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-region__cities li:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

/* ---------- 站点信息 ---------- */

.page-about .about-facts {
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-facts__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-facts__row dt {
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--muted);
}

.page-about .about-facts__row dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text);
  word-break: break-word;
}

.page-about .about-facts__row dd.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
  color: var(--silver);
}

.page-about .about-facts__note {
  margin: 16px 0 0;
  font-size: 13px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-facts__note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 224, 208, 0.35);
}

.page-about .about-facts__note a:hover {
  border-bottom-color: var(--cyan);
}

/* ---------- 更新节奏 ---------- */

.page-about .cadence-grid {
  display: grid;
  gap: 1px;
  margin-top: clamp(24px, 4vw, 40px);
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .cadence-card {
  position: relative;
  padding: clamp(24px, 3.4vw, 38px);
  background: var(--ink);
  overflow: hidden;
}

.page-about .cadence-card--amber {
  background: linear-gradient(150deg, rgba(255, 162, 58, 0.08), rgba(6, 17, 15, 0.95) 58%);
}

.page-about .cadence-card__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(46px, 9vw, 76px);
  font-weight: 200;
  line-height: 0.9;
  letter-spacing: -0.02em;
  color: var(--cyan);
  margin-bottom: 18px;
}

.page-about .cadence-card--amber .cadence-card__num {
  color: var(--amber);
}

.page-about .cadence-card h3 {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--white);
}

.page-about .cadence-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 结尾引导 ---------- */

.page-about .about-cta {
  padding-bottom: clamp(56px, 9vw, 112px);
}

.page-about .about-cta__inner {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
  align-items: center;
  padding: clamp(26px, 4vw, 44px);
  border: 1px solid var(--about-rule);
  background: linear-gradient(140deg, rgba(34, 224, 208, 0.07), rgba(11, 27, 43, 0.85) 55%);
}

.page-about .about-cta__inner .h2 {
  margin-bottom: 12px;
  font-size: clamp(24px, 3.6vw, 40px);
}

.page-about .about-cta__inner p {
  margin: 0;
  max-width: 56ch;
  color: var(--muted);
}

.page-about .about-cta .btn {
  justify-self: start;
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-facts__row {
    grid-template-columns: minmax(120px, 180px) minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }
}

@media (min-width: 760px) {
  .page-about .arc-timeline::before {
    left: 104px;
  }

  .page-about .arc-node {
    padding: 0 0 34px 142px;
  }

  .page-about .arc-node::before {
    left: 97px;
  }

  .page-about .arc-node__year {
    position: absolute;
    left: 0;
    top: 0;
    width: 84px;
    margin-bottom: 0;
    text-align: right;
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(280px, 0.85fr);
    align-items: end;
    gap: clamp(36px, 5vw, 72px);
  }

  .page-about .about-review {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(32px, 4vw, 56px);
  }

  .page-about .about-region {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
  }

  .page-about .about-cta .btn {
    justify-self: end;
  }
}

@media (min-width: 940px) {
  .page-about .about-versions__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(36px, 4vw, 60px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .arc-node__more {
    transition: opacity 120ms linear;
  }

  .page-about .crew-card,
  .page-about .crew-card::before,
  .page-about .about-steps li,
  .page-about .about-region__cities li {
    transition: none;
  }

  .page-about .crew-card:hover {
    transform: none;
  }
}