.page-about {
  --about-line: rgba(201, 162, 39, 0.28);
  --about-line-strong: rgba(201, 162, 39, 0.55);
  --about-jade: rgba(18, 58, 60, 0.62);
  --about-indigo: rgba(36, 26, 58, 0.58);
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
}

.page-about .about-hero {
  padding-block: 30px 6px;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 7vw, 60px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 14px 0 18px;
  max-width: 13ch;
  color: var(--paper);
}

.page-about .lede {
  font-size: 16px;
  line-height: 1.78;
  max-width: 60ch;
  color: rgba(242, 239, 233, 0.82);
  margin: 0;
}

.page-about .about-facts {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-facts li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  background: var(--ink-2);
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--mist);
}

.page-about .about-facts .index-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--gold);
  flex: none;
}

/* 贯穿全页的纵向轴线 */
.page-about .about-flow {
  margin-top: 34px;
  padding-bottom: 40px;
}

.page-about .about-block {
  position: relative;
  padding: 30px 16px 30px 22px;
  border-left: 2px solid var(--about-line);
}

.page-about .about-block::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 36px;
  width: 6px;
  height: 6px;
  border: 2px solid var(--gold);
  border-radius: 50%;
  background: var(--ink);
}

.page-about .about-block--jade {
  background: var(--about-jade);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
}

.page-about .about-block--indigo {
  background: var(--about-indigo);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
}

.page-about .about-block--wide {
  background: linear-gradient(180deg, rgba(18, 58, 60, 0.5), rgba(8, 20, 31, 0));
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
}

.page-about .about-block--tail {
  border-left-color: var(--about-line-strong);
}

.page-about .block-index {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .about-block h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(22px, 4.6vw, 32px);
  line-height: 1.24;
  letter-spacing: -0.01em;
  margin: 10px 0 16px;
  max-width: 20ch;
}

.page-about .about-block p {
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(242, 239, 233, 0.84);
  margin: 0 0 14px;
  max-width: 62ch;
}

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

.page-about .about-block a {
  color: var(--gold-soft);
  text-decoration-color: var(--about-line-strong);
  text-underline-offset: 3px;
  transition: color var(--dur) var(--ease);
}

.page-about .about-block a:hover {
  color: var(--gold);
}

/* 时间线 */
.page-about .about-banner {
  margin: 22px 0 6px;
}

.page-about .milestones {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
}

.page-about .milestone {
  position: relative;
  padding: 16px 0 16px 26px;
  border-radius: var(--radius-md);
  transition: background var(--dur) var(--ease);
}

.page-about .milestone::before {
  content: "";
  position: absolute;
  left: 0;
  top: 22px;
  width: 6px;
  height: 6px;
  border: 1px solid var(--gold);
  border-radius: 50%;
  box-sizing: content-box;
}

.page-about .milestone::after {
  content: "";
  position: absolute;
  left: 3px;
  top: 32px;
  bottom: 0;
  width: 2px;
  background: var(--about-line);
}

.page-about .milestone:last-child::after {
  display: none;
}

.page-about .milestone:hover,
.page-about .milestone:focus-within {
  background: rgba(201, 162, 39, 0.07);
}

.page-about .ms-year {
  display: block;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .ms-title {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  margin: 6px 0 6px;
  line-height: 1.4;
}

.page-about .ms-desc {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--mist);
  margin: 0;
  max-width: 46ch;
}

/* 三层方法论 */
.page-about .method-grid {
  display: grid;
  gap: 22px;
  margin-top: 22px;
}

.page-about .layer-stack {
  display: grid;
  gap: 8px;
}

.page-about .layer {
  padding: 16px 16px 16px 18px;
  border-left: 3px solid var(--about-line-strong);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: rgba(8, 20, 31, 0.55);
  outline: none;
  transition: border-color var(--dur) var(--ease),
    background var(--dur) var(--ease),
    transform var(--dur) var(--ease);
}

.page-about .layer:nth-child(2) {
  margin-inline-start: 12px;
}

.page-about .layer:nth-child(3) {
  margin-inline-start: 24px;
}

.page-about .layer:hover,
.page-about .layer:focus-visible,
.page-about .layer:focus-within {
  border-left-color: var(--celadon);
  background: rgba(18, 58, 60, 0.85);
  transform: translateX(3px);
}

.page-about .layer-num {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--celadon);
}

.page-about .layer h3 {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  margin: 6px 0 6px;
}

.page-about .layer p {
  font-size: 14.5px;
  line-height: 1.72;
  color: rgba(242, 239, 233, 0.8);
  margin: 0;
}

.page-about .method-figure {
  margin: 0;
}

.page-about .method-result {
  margin-top: 22px;
  padding-top: 16px;
  border-top: 1px solid var(--about-line);
}

/* 团队 */
.page-about .team-grid {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .team-cell {
  padding: 16px 2px 18px;
  border-top: 1px solid var(--about-line);
  transition: border-color var(--dur) var(--ease),
    transform var(--dur) var(--ease);
}

.page-about .team-cell:hover,
.page-about .team-cell:focus-within {
  border-top-color: var(--gold);
  transform: translateY(-2px);
}

.page-about .team-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--coral);
}

.page-about .team-cell h3 {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  margin: 6px 0 6px;
}

.page-about .team-cell p {
  font-size: 14.5px;
  line-height: 1.72;
  color: rgba(242, 239, 233, 0.8);
  margin: 0;
  max-width: 44ch;
}

.page-about .sub-title {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  margin: 34px 0 4px;
  padding-top: 20px;
  border-top: 1px solid var(--about-line);
}

.page-about .flow-steps {
  list-style: none;
  margin: 14px 0 20px;
  padding: 0;
  display: grid;
  gap: 14px;
  counter-reset: none;
}

.page-about .flow-steps li {
  padding-left: 14px;
  border-left: 2px solid var(--about-line-strong);
}

.page-about .flow-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .flow-steps h4 {
  font-family: var(--font-display);
  font-size: 15.5px;
  font-weight: 700;
  margin: 4px 0 4px;
}

.page-about .flow-steps p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
  margin: 0;
}

/* 覆盖与规模 */
.page-about .about-block--wide .media {
  margin: 22px 0 20px;
}

.page-about .coverage-stats {
  display: grid;
  gap: 0;
  margin: 0;
  border-top: 1px solid var(--about-line);
}

.page-about .coverage-stats div {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 6px 16px;
  padding: 12px 0;
  border-bottom: 1px solid var(--about-line);
}

.page-about .coverage-stats dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--mist);
}

.page-about .coverage-stats dd {
  margin: 0;
  font-size: 15px;
  font-weight: 500;
  color: var(--paper);
}

.page-about .coverage-ticks {
  height: 46px;
  margin-top: 22px;
  border-top: 1px solid var(--about-line-strong);
  background-image: repeating-linear-gradient(
    90deg,
    var(--about-line) 0 1px,
    transparent 1px 18px
  );
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 100%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 100%);
}

/* 收尾 */
.page-about .connect-list {
  list-style: none;
  margin: 22px 0 18px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .connect-list li {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 14px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--about-line);
}

.page-about .connect-label {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.12em;
  color: var(--mist);
  flex: none;
  min-width: 72px;
}

.page-about .connect-list a,
.page-about .connect-list span:not(.connect-label) {
  font-size: 15px;
  line-height: 1.6;
  color: var(--paper);
}

.page-about .connect-list a {
  color: var(--gold-soft);
}

.page-about .tail-note {
  font-size: 13.5px !important;
  line-height: 1.7;
  color: var(--mist) !important;
  margin-bottom: 20px !important;
}

.page-about .about-block--tail .btn {
  display: inline-flex;
  align-items: center;
}

/* 中屏 */
@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .about-block {
    padding: 36px 28px 36px 30px;
  }

  .page-about .about-block::before {
    left: -7px;
    top: 42px;
    width: 8px;
    height: 8px;
  }

  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 26px;
  }

  .page-about .team-cell:nth-child(2) {
    margin-top: 24px;
  }

  .page-about .team-cell:nth-child(3) {
    margin-top: 0;
  }

  .page-about .team-cell:nth-child(4) {
    margin-top: 24px;
  }

  .page-about .flow-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px 22px;
  }

  .page-about .coverage-stats div {
    padding: 14px 0;
  }
}

/* 桌面 */
@media (min-width: 960px) {
  .page-about .about-flow {
    margin-top: 46px;
    padding-bottom: 20px;
  }

  .page-about .about-block {
    padding: 44px 40px 44px 36px;
  }

  .page-about .about-block::before {
    top: 52px;
  }

  .page-about .method-grid {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 0.9fr);
    align-items: start;
    gap: 34px;
  }

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

  .page-about .flow-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .coverage-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 40px;
  }

  .page-about .connect-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .connect-list li {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    padding-bottom: 0;
    border-bottom: none;
    border-left: 1px solid var(--about-line);
    padding-left: 14px;
  }
}