.page-about {
  --about-gap: clamp(20px, 3vw, 40px);
  --about-axis-x: 26px;
  background: var(--yh-cream);
  color: var(--yh-ink);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about .section {
  padding: clamp(48px, 7vw, 96px) 0;
}

.page-about .about-cover-river {
  position: absolute;
  inset: auto 0 -6% 0;
  width: 100%;
  height: clamp(180px, 34vw, 420px);
  pointer-events: none;
  opacity: .55;
}

.page-about .about-cover-river path {
  fill: none;
  stroke: var(--yh-silver);
  stroke-width: 2;
}

.page-about .about-cover-river path:first-child {
  stroke: var(--yh-blue);
  stroke-opacity: .28;
  stroke-width: 3;
}

.page-about .about-cover {
  position: relative;
  padding: clamp(26px, 5vw, 60px) 0 clamp(40px, 6vw, 88px);
  border-bottom: 1px solid rgba(27, 58, 107, .14);
  background: linear-gradient(180deg, var(--yh-cream) 0%, var(--yh-mist) 100%);
  overflow: hidden;
}

.page-about .about-cover-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(26px, 4vw, 52px);
}

.page-about .about-cover-main h1 {
  margin: 14px 0 18px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(34px, 6.4vw, 78px);
  line-height: 1.06;
  letter-spacing: .04em;
  color: var(--yh-blue);
  max-width: 16em;
}

.page-about .about-cover-main .lede {
  max-width: 60ch;
  font-size: clamp(16px, 1.6vw, 18px);
  line-height: 1.8;
  color: var(--yh-ink-soft);
}

.page-about .about-cover-facts {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(14px, 2.4vw, 30px);
  margin-top: clamp(22px, 3vw, 34px);
  padding-top: clamp(18px, 2.6vw, 26px);
  border-top: 1px solid rgba(27, 58, 107, .16);
}

.page-about .about-cover-facts .stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.page-about .about-cover-facts .stat-value {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 700;
  color: var(--yh-blue);
  line-height: 1.1;
}

.page-about .about-cover-facts .stat-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--yh-gauge);
}

.page-about .about-index {
  border-radius: var(--radius-lg);
  background: linear-gradient(158deg, var(--yh-silver) 0%, var(--yh-mist) 82%);
  padding: clamp(18px, 2.4vw, 26px);
  box-shadow: var(--shadow-1);
  align-self: start;
}

.page-about .about-index-title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--yh-blue-deep);
  text-transform: uppercase;
}

.page-about .about-index-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-index-list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 6px;
  border-radius: var(--radius-sm);
  color: var(--yh-blue-deep);
  text-decoration: none;
  font-size: 15px;
  transition: background-color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  background: rgba(255, 255, 255, .7);
  padding-left: 12px;
}

.page-about .about-index-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--yh-copper-deep);
}

/* 运营脉络 */

.page-about .about-history {
  background: linear-gradient(180deg, var(--yh-mist) 0%, var(--yh-cream) 34%);
}

.page-about .about-history-head {
  display: grid;
  gap: var(--about-gap);
  margin-bottom: clamp(32px, 5vw, 56px);
}

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

.page-about .about-history-figure img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-2);
}

.page-about .about-axis {
  position: relative;
  padding-left: var(--about-axis-x);
}

.page-about .about-axis-rail {
  position: absolute;
  top: 6px;
  bottom: 6px;
  left: 7px;
  width: 3px;
  border-radius: var(--pill);
  background: var(--grad-rail);
  opacity: .5;
}

.page-about .about-stages {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-stage {
  position: relative;
}

.page-about .about-stage-dot {
  position: absolute;
  top: 20px;
  left: calc(var(--about-axis-x) * -1 + 1px);
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--yh-cream);
  border: 3px solid var(--yh-silver);
}

.page-about .about-stage[data-open] .about-stage-dot {
  background: var(--yh-copper);
  border-color: var(--yh-copper);
  box-shadow: 0 0 0 4px rgba(201, 111, 46, .18);
}

.page-about .about-stage-heading {
  margin: 0;
  font-size: 1rem;
  font-weight: inherit;
}

.page-about .about-stage-trigger {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 6px;
  align-items: flex-start;
  text-align: left;
  border: 0;
  cursor: pointer;
  padding: 16px 20px;
  border-radius: var(--radius-md);
  background: #fff;
  box-shadow: var(--shadow-1);
  transition: box-shadow var(--dur) var(--ease), transform var(--dur) var(--ease);
  font-family: inherit;
}

.page-about .about-stage-trigger:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-2);
}

.page-about .about-stage[data-open] .about-stage-trigger {
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
  background: linear-gradient(160deg, var(--yh-silver), var(--yh-mist));
}

.page-about .about-stage-scale {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--yh-copper-deep);
}

.page-about .about-stage-name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(18px, 2.1vw, 23px);
  letter-spacing: .04em;
  color: var(--yh-blue);
  line-height: 1.3;
}

.page-about .about-stage-panel {
  padding: 18px 20px 22px;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  background: var(--yh-celadon-light);
}

.page-about .about-stage-panel p {
  margin: 0 0 14px;
  line-height: 1.8;
  color: var(--yh-ink);
}

.page-about .about-assets {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .about-assets li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--yh-ink-soft);
}

.page-about .about-assets li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: .72em;
  width: 9px;
  height: 2px;
  border-radius: var(--pill);
  background: var(--yh-celadon);
}

/* 型号与核参数 */

.page-about .about-blocks-head {
  max-width: 70ch;
  margin-bottom: clamp(28px, 4vw, 48px);
}

.page-about .about-blocks-grid {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-block {
  padding: clamp(22px, 3vw, 34px);
  border-radius: var(--radius-lg);
  background: #fff;
  box-shadow: var(--shadow-1);
}

.page-about .about-block--params {
  background: linear-gradient(170deg, var(--yh-mist) 0%, #fff 60%);
}

.page-about .about-block h3 {
  margin: 14px 0 12px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(20px, 2.4vw, 26px);
  letter-spacing: .04em;
  color: var(--yh-blue);
}

.page-about .about-block p {
  margin: 0 0 16px;
  line-height: 1.8;
  color: var(--yh-ink-soft);
}

.page-about .about-block-list {
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-block-list li {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  background: var(--yh-celadon-light);
  font-size: 15px;
  line-height: 1.65;
  color: var(--yh-ink);
}

.page-about .about-block-key {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--yh-celadon);
}

.page-about .about-block .data-table-wrap {
  margin-bottom: 20px;
}

.page-about .about-block-link {
  margin: 0;
}

.page-about .about-block .btn-quiet {
  padding: 10px 18px;
  border-radius: var(--pill);
  font-size: 14px;
  text-decoration: none;
}

/* 选型方法 */

.page-about .about-selection {
  background: var(--yh-blue);
  color: var(--yh-mist);
}

.page-about .about-selection-inner {
  display: grid;
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}

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

.page-about .about-selection-figure img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-2);
}

.page-about .about-selection .media-caption {
  color: rgba(244, 247, 251, .62);
}

.page-about .about-selection .eyebrow {
  color: var(--yh-silver);
}

.page-about .about-selection .section-title {
  color: #fff;
  margin: 12px 0 18px;
}

.page-about .about-selection-body > p {
  max-width: 62ch;
  line-height: 1.85;
  color: rgba(244, 247, 251, .82);
}

.page-about .about-lines {
  list-style: none;
  counter-reset: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-line {
  padding: 18px 20px;
  border-radius: var(--radius-md);
  border-left: 3px solid var(--yh-copper);
  background: rgba(200, 212, 227, .1);
}

.page-about .about-line-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--yh-copper);
}

.page-about .about-line h3 {
  margin: 6px 0 8px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(17px, 2vw, 21px);
  letter-spacing: .04em;
  color: #fff;
}

.page-about .about-line p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(244, 247, 251, .78);
}

.page-about .about-selection-note {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid rgba(200, 212, 227, .24);
  font-size: 15px;
  line-height: 1.8;
  color: rgba(244, 247, 251, .74);
}

/* 合作生态 */

.page-about .about-partners {
  background: linear-gradient(180deg, var(--yh-cream) 0%, var(--yh-mist) 100%);
}

.page-about .about-partners-head {
  max-width: 68ch;
  margin-bottom: clamp(26px, 4vw, 44px);
}

.page-about .about-eco {
  display: grid;
  gap: var(--about-gap);
  align-items: center;
}

.page-about .about-eco-graph svg {
  width: 100%;
  max-width: 380px;
  height: auto;
  display: block;
  margin: 0 auto;
}

.page-about .eco-ring {
  fill: none;
  stroke: var(--yh-silver);
  stroke-width: 1.5;
  stroke-dasharray: 5 7;
}

.page-about .eco-link {
  stroke: var(--yh-gauge);
  stroke-width: 1.4;
  opacity: .5;
}

.page-about .eco-core {
  fill: var(--yh-blue);
}

.page-about .eco-core-text {
  fill: #fff;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 900;
  text-anchor: middle;
  letter-spacing: .06em;
}

.page-about .eco-core-text--sub {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .16em;
  fill: var(--yh-silver);
}

.page-about .eco-node circle {
  fill: var(--yh-silver);
  stroke: var(--yh-blue);
  stroke-width: 2;
}

.page-about .eco-node text {
  font-family: var(--font-mono);
  font-size: 15px;
  text-anchor: middle;
  fill: var(--yh-blue-deep);
}

.page-about .eco-node {
  transform-box: fill-box;
  transform-origin: center;
  transition: transform var(--dur) var(--ease);
  cursor: default;
}

.page-about .eco-node:hover {
  transform: scale(1.12);
}

.page-about .eco-node--channel circle { fill: var(--yh-blue); }
.page-about .eco-node--channel text { fill: #fff; }
.page-about .eco-node--content circle { fill: var(--yh-celadon); stroke: var(--yh-celadon); }
.page-about .eco-node--content text { fill: #fff; }
.page-about .eco-node--tech circle { fill: var(--yh-copper); stroke: var(--yh-copper); }
.page-about .eco-node--tech text { fill: #fff; }

.page-about .about-partner-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-partner {
  padding: 22px 22px 20px;
  border-radius: var(--radius-lg);
  background: #fff;
  box-shadow: var(--shadow-1);
  border-top: 4px solid var(--yh-blue);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-partner:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-2);
}

.page-about .about-partner--content { border-top-color: var(--yh-celadon); }
.page-about .about-partner--tech { border-top-color: var(--yh-copper); }

.page-about .about-partner h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(18px, 2.2vw, 22px);
  letter-spacing: .04em;
  color: var(--yh-blue);
}

.page-about .about-partner p {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--yh-ink-soft);
}

.page-about .about-partner-meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--yh-gauge);
}

.page-about .about-partners-note {
  margin: clamp(24px, 3vw, 34px) 0 0;
  font-size: 15px;
  color: var(--yh-ink-soft);
}

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

/* 服务网络 */

.page-about .about-coverage {
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, var(--yh-silver) 0%, var(--yh-mist) 100%);
}

.page-about .about-coverage-bg {
  position: absolute;
  inset: 0;
  opacity: .38;
}

.page-about .about-coverage-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.page-about .about-coverage-inner {
  position: relative;
  z-index: 1;
}

.page-about .about-coverage .section-head {
  max-width: 66ch;
  margin-bottom: clamp(26px, 4vw, 42px);
}

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

.page-about .about-coverage-card {
  padding: 22px;
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, .88);
  backdrop-filter: blur(2px);
  box-shadow: var(--shadow-1);
}

.page-about .about-coverage-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .16em;
  padding: 5px 12px;
  border-radius: var(--pill);
  background: var(--yh-celadon-light);
  color: var(--yh-celadon);
}

.page-about .about-coverage-card h3 {
  margin: 12px 0 10px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 20px;
  letter-spacing: .04em;
  color: var(--yh-blue);
}

.page-about .about-coverage-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--yh-ink-soft);
}

.page-about .about-coverage-note {
  margin: clamp(22px, 3vw, 30px) 0 0;
  font-size: 15px;
  color: var(--yh-ink-soft);
}

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

/* 洽谈 */

.page-about .about-dialog {
  background: var(--yh-cream);
}

.page-about .about-dialog-card {
  display: grid;
  gap: clamp(24px, 3.6vw, 46px);
  padding: clamp(26px, 4vw, 52px);
  border-radius: var(--radius-lg);
  background: linear-gradient(160deg, var(--yh-blue) 0%, var(--yh-blue-deep) 100%);
  color: var(--yh-mist);
  box-shadow: var(--shadow-2);
}

.page-about .about-dialog .eyebrow {
  color: var(--yh-silver);
}

.page-about .about-dialog .section-title {
  color: #fff;
  margin: 12px 0 16px;
}

.page-about .about-dialog-main > p {
  max-width: 58ch;
  line-height: 1.85;
  color: rgba(244, 247, 251, .82);
}

.page-about .about-checklist {
  list-style: none;
  margin: 24px 0 28px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-checklist li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(200, 212, 227, .18);
  font-size: 15px;
  line-height: 1.75;
  color: rgba(244, 247, 251, .86);
}

.page-about .about-check-num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--yh-copper);
  padding-top: 3px;
}

.page-about .about-dialog-aside {
  padding: 24px;
  border-radius: var(--radius-md);
  background: rgba(200, 212, 227, .12);
  border: 1px solid rgba(200, 212, 227, .24);
  align-self: start;
}

.page-about .about-dialog-aside h3 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 19px;
  letter-spacing: .04em;
  color: #fff;
}

.page-about .about-dialog-contact {
  margin: 0 0 16px;
  display: grid;
  gap: 4px;
}

.page-about .about-dialog-contact dt {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .14em;
  color: var(--yh-silver);
  margin-top: 10px;
}

.page-about .about-dialog-contact dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: #fff;
  word-break: break-word;
}

.page-about .about-dialog-contact a {
  color: #fff;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-dialog-note {
  margin: 0;
  font-size: 13px;
  line-height: 1.75;
  color: rgba(244, 247, 251, .68);
}

/* 跳转胶囊 */

.page-about .about-jump {
  position: fixed;
  right: clamp(14px, 2.4vw, 28px);
  bottom: clamp(14px, 2.4vw, 28px);
  z-index: 20;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 18px;
  border-radius: var(--pill);
  background: var(--yh-cream);
  color: var(--yh-blue);
  border: 1.5px solid var(--yh-copper);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .1em;
  text-decoration: none;
  box-shadow: var(--shadow-2);
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-jump:hover,
.page-about .about-jump:focus-visible {
  background: var(--yh-copper);
  color: #fff;
}

.page-about .about-jump-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--yh-copper);
}

.page-about .about-jump:hover .about-jump-dot {
  background: #fff;
}

/* 响应式 */

@media (min-width: 720px) {
  .page-about .about-coverage-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

  .page-about .about-stage-trigger {
    flex-direction: row;
    align-items: baseline;
    gap: 18px;
  }

  .page-about .about-stage-scale {
    flex: none;
    min-width: 118px;
  }
}

@media (min-width: 1020px) {
  .page-about .about-cover-inner {
    grid-template-columns: minmax(0, 1fr) 300px;
    align-items: start;
  }

  .page-about .about-history-head {
    grid-template-columns: minmax(0, 1fr) minmax(0, .82fr);
    align-items: start;
  }

  .page-about .about-selection-inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
  }

  .page-about .about-eco {
    grid-template-columns: 360px minmax(0, 1fr);
  }

  .page-about .about-eco-graph {
    position: sticky;
    top: 96px;
  }

  .page-about .about-dialog-card {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
  }

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

  .page-about .about-partner--channel {
    grid-column: 1 / -1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-stage-trigger,
  .page-about .about-partner,
  .page-about .eco-node,
  .page-about .about-jump,
  .page-about .about-index-list a {
    transition: none;
  }

  .page-about .about-stage-trigger:hover,
  .page-about .about-partner:hover,
  .page-about .eco-node:hover {
    transform: none;
  }
}