.page-about {
  --about-rail-w: 176px;
  --about-rail-x: 7px;
  --about-pad: 44px;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  color: var(--paper);
  padding: clamp(26px, 3.6vw, 48px) 0 clamp(54px, 7vw, 100px);
  background:
    radial-gradient(90% 118% at 92% 2%, rgba(23, 168, 139, 0.22), transparent 62%),
    linear-gradient(168deg, var(--ink-900) 0%, var(--indigo-800) 58%, #10203F 100%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(135deg, rgba(233, 237, 245, 0.05) 0 1px, transparent 1px 24px);
}

.page-about .about-hero > .wrap {
  position: relative;
  z-index: 1;
}

.page-about .about-crumb {
  margin-bottom: clamp(22px, 3vw, 38px);
  font-size: 14px;
  color: rgba(233, 237, 245, 0.62);
}

.page-about .about-crumb a {
  color: rgba(233, 237, 245, 0.86);
  text-decoration: none;
}

.page-about .about-crumb a:hover {
  color: var(--jade);
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(30px, 4vw, 56px);
}

.page-about .about-h1 {
  margin: 0 0 20px;
  font-family: var(--font-sans);
  font-size: clamp(2rem, 5.4vw, 3.5rem);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-lede {
  max-width: 46ch;
  margin: 0;
  font-size: clamp(1rem, 1.15vw, 1.125rem);
  line-height: 1.85;
  color: rgba(233, 237, 245, 0.8);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 28px;
}

.page-about .about-figures {
  padding: clamp(20px, 2.2vw, 28px);
  background: rgba(15, 27, 61, 0.72);
  border: 1px solid rgba(34, 55, 107, 0.85);
  clip-path: var(--cut-md);
}

.page-about .about-figures-title {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: rgba(233, 237, 245, 0.58);
}

.page-about .about-figures-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-figure {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 13px 0;
  border-top: 1px solid rgba(233, 237, 245, 0.12);
}

.page-about .about-figure:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-fig-num {
  flex: none;
  min-width: 5ch;
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  line-height: 1.05;
  font-weight: 500;
  color: var(--gold);
}

.page-about .about-fig-label {
  font-size: 14px;
  line-height: 1.65;
  color: rgba(233, 237, 245, 0.74);
}

/* ---------- 长卷主体 ---------- */

.page-about .about-body {
  padding: clamp(50px, 6.5vw, 96px) 0 clamp(60px, 7vw, 110px);
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 3.4vw, 56px);
}

.page-about .about-rail-col {
  min-width: 0;
}

.page-about .about-rail {
  display: flex;
  gap: 8px;
  align-items: center;
  overflow-x: auto;
  padding-bottom: 8px;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .about-rail-title {
  display: none;
}

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

.page-about .chapter-rail-link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  white-space: nowrap;
  padding: 7px 12px;
  font-size: 13.5px;
  color: var(--muted);
  text-decoration: none;
  border: 1px solid rgba(34, 55, 107, 0.24);
  transition: color 0.18s var(--ease), background-color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .chapter-rail-link .mono {
  font-size: 11.5px;
  color: var(--jade-deep);
}

.page-about .chapter-rail-link:hover,
.page-about .chapter-rail-link:focus-visible {
  color: var(--ink);
  background: rgba(23, 168, 139, 0.1);
  border-color: rgba(23, 168, 139, 0.38);
}

.page-about .chapter-rail-link.is-active,
.page-about .chapter-rail-link[aria-current="true"] {
  color: var(--jade-deep);
  background: rgba(23, 168, 139, 0.14);
  border-color: rgba(23, 168, 139, 0.5);
}

.page-about .about-stream {
  position: relative;
  min-width: 0;
}

.page-about .about-stream::before {
  content: "";
  position: absolute;
  left: var(--about-rail-x);
  top: 12px;
  bottom: 12px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--indigo-600) 0%, var(--jade) 42%, var(--jade-deep) 100%);
}

.page-about .about-chapter {
  position: relative;
  padding-left: var(--about-pad);
  padding-bottom: clamp(46px, 6vw, 86px);
}

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

.page-about .about-chapter::before {
  content: "";
  position: absolute;
  left: calc(var(--about-rail-x) - 6px);
  top: 9px;
  width: 14px;
  height: 14px;
  box-sizing: border-box;
  border-radius: 50%;
  background: var(--paper);
  border: 3px solid var(--jade);
  transition: transform 0.18s var(--ease), background-color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-chapter:hover::before {
  transform: scale(1.22);
  background: var(--gold-soft);
  border-color: var(--gold);
}

.page-about .about-chapter-head {
  display: flex;
  align-items: baseline;
  gap: clamp(12px, 1.6vw, 20px);
  margin-bottom: 14px;
}

.page-about .about-chapter-no {
  flex: none;
  font-size: clamp(1.6rem, 3.4vw, 2.6rem);
  line-height: 1;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: rgba(23, 168, 139, 0.42);
}

.page-about .about-chapter-title {
  margin: 0;
  font-size: clamp(1.32rem, 2.4vw, 2rem);
  font-weight: 800;
  line-height: 1.26;
  letter-spacing: -0.015em;
  color: var(--ink);
}

.page-about .about-chapter-lead {
  max-width: 62ch;
  margin: 0 0 clamp(22px, 2.6vw, 32px);
  font-size: clamp(0.97rem, 1.08vw, 1.0625rem);
  line-height: 1.9;
  color: var(--muted);
}

/* ---------- 时间轴 ---------- */

.page-about .about-timeline {
  list-style: none;
  margin: 0 0 clamp(24px, 3vw, 38px);
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-stage {
  padding: 20px clamp(18px, 2.2vw, 26px) 22px;
  background: var(--paper);
  border-left: 3px solid var(--jade);
  transition: transform 0.18s var(--ease), border-color 0.18s var(--ease), box-shadow 0.18s var(--ease);
}

.page-about .about-stage:hover {
  transform: translateY(-4px);
  border-left-color: var(--gold);
  box-shadow: 0 18px 34px -26px rgba(15, 27, 61, 0.6);
}

.page-about .about-stage-tag {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--jade-deep);
}

.page-about .about-stage-title {
  margin: 0 0 8px;
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-stage-text {
  max-width: 58ch;
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 图片容器 ---------- */

.page-about .about-media {
  margin: 0;
  overflow: hidden;
  background: var(--indigo-800);
  clip-path: var(--cut-md);
}

.page-about .about-media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-media .media-caption {
  margin: 0;
  padding: 12px 16px 14px;
  background: var(--indigo-800);
  color: rgba(233, 237, 245, 0.72);
  font-size: 13px;
  line-height: 1.7;
}

.page-about .about-media--team {
  max-width: 920px;
}

/* ---------- 团队 ---------- */

.page-about .about-teams {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-bottom: clamp(24px, 3vw, 38px);
  background: rgba(34, 55, 107, 0.18);
  border: 1px solid rgba(34, 55, 107, 0.18);
}

.page-about .about-team {
  padding: clamp(20px, 2.4vw, 28px);
  background: var(--paper);
}

.page-about .about-team-name {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 10px;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-team-name::before {
  content: "";
  flex: none;
  width: 8px;
  height: 8px;
  background: var(--jade);
}

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

/* ---------- 规模数字 ---------- */

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-bottom: clamp(22px, 2.8vw, 34px);
  background: rgba(34, 55, 107, 0.18);
}

.page-about .about-stat {
  display: grid;
  gap: 8px;
  align-content: start;
  padding: clamp(18px, 2.2vw, 26px) clamp(14px, 1.8vw, 20px);
  background: var(--paper);
}

.page-about .about-stat-num {
  font-size: clamp(1.5rem, 2.9vw, 2.2rem);
  line-height: 1;
  font-weight: 500;
  color: var(--jade-deep);
}

.page-about .about-stat:nth-child(3) .about-stat-num {
  color: var(--ink);
}

.page-about .about-stat-label {
  font-size: 13px;
  line-height: 1.65;
  color: var(--muted);
}

/* ---------- 地图图例 ---------- */

.page-about .about-legend {
  margin-bottom: clamp(22px, 2.8vw, 34px);
  padding: clamp(20px, 2.6vw, 30px);
  background: linear-gradient(142deg, var(--indigo-800) 0%, var(--ink-900) 100%);
  clip-path: var(--cut-md);
}

.page-about .about-legend-title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: rgba(233, 237, 245, 0.58);
}

.page-about .about-legend-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-legend-item {
  display: grid;
  grid-template-columns: 16px minmax(0, 1fr);
  column-gap: 12px;
  row-gap: 3px;
  padding: 13px 0;
  border-top: 1px solid rgba(233, 237, 245, 0.12);
}

.page-about .about-legend-item:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-legend-dot {
  grid-column: 1;
  grid-row: 1 / span 2;
  align-self: start;
  width: 10px;
  height: 10px;
  margin-top: 6px;
  border-radius: 50%;
}

.page-about .about-legend-dot--jade { background: var(--jade); }
.page-about .about-legend-dot--gold { background: var(--gold); }
.page-about .about-legend-dot--mist { background: var(--mist); }
.page-about .about-legend-dot--deep { background: var(--jade-deep); }

.page-about .about-legend-name {
  grid-column: 2;
  font-size: 15px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .about-legend-note {
  grid-column: 2;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(233, 237, 245, 0.66);
}

/* ---------- 更新节奏 ---------- */

.page-about .about-rhythm {
  list-style: none;
  margin: 0 0 clamp(20px, 2.6vw, 30px);
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .about-rhythm-item {
  padding: 20px 18px 22px;
  background: var(--paper);
  border-top: 3px solid var(--jade);
  transition: transform 0.18s var(--ease), border-color 0.18s var(--ease), box-shadow 0.18s var(--ease);
}

.page-about .about-rhythm-item:hover {
  transform: translateY(-4px);
  border-top-color: var(--gold);
  box-shadow: 0 18px 34px -26px rgba(15, 27, 61, 0.6);
}

.page-about .about-rhythm-num {
  display: block;
  margin-bottom: 10px;
  font-size: 12px;
  color: var(--jade-deep);
}

.page-about .about-rhythm-item h3 {
  margin: 0 0 8px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-rhythm-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-inline-note {
  max-width: 62ch;
  margin: 0;
  font-size: 15px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .about-inline-note a {
  color: var(--jade-deep);
  text-decoration: none;
  border-bottom: 1px solid rgba(14, 124, 103, 0.4);
}

.page-about .about-inline-note a:hover {
  color: var(--ink);
  border-bottom-color: var(--gold);
}

/* ---------- 协作网络 ---------- */

.page-about .about-partner-panel {
  padding: clamp(22px, 3vw, 38px);
  background: linear-gradient(155deg, var(--ink-900) 0%, var(--indigo-800) 100%);
  clip-path: var(--cut-md);
}

.page-about .about-partner-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-partner-list > li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  column-gap: 16px;
  row-gap: 5px;
  padding: 18px 0;
  border-top: 1px solid rgba(233, 237, 245, 0.14);
}

.page-about .about-partner-list > li:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-partner-no {
  grid-column: 1;
  grid-row: 1 / span 2;
  padding-top: 4px;
  font-size: 12.5px;
  color: var(--gold);
}

.page-about .about-partner-list h3 {
  grid-column: 2;
  margin: 0;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-partner-list p {
  grid-column: 2;
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(233, 237, 245, 0.72);
}

/* ---------- 服务做法 ---------- */

.page-about .about-commit {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-commit-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 7px;
  padding: 18px 0;
  border-top: 1px dashed rgba(34, 55, 107, 0.32);
}

.page-about .about-commit-item:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-commit-key {
  margin: 0;
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--jade-deep);
}

.page-about .about-commit-text {
  max-width: 62ch;
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 收口带 ---------- */

.page-about .about-lead-out {
  position: relative;
  overflow: hidden;
  padding: clamp(38px, 4.6vw, 62px) 0;
  color: var(--paper);
  background: linear-gradient(180deg, var(--indigo-800) 0%, var(--ink-900) 100%);
}

.page-about .about-lead-out::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(135deg, rgba(233, 237, 245, 0.04) 0 1px, transparent 1px 22px);
}

.page-about .about-lead-out > .wrap {
  position: relative;
  z-index: 1;
}

.page-about .about-lead-out-title {
  margin: 0 0 20px;
  font-size: clamp(1.1rem, 1.8vw, 1.4rem);
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .about-lead-out-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: rgba(233, 237, 245, 0.16);
}

.page-about .about-lead-out-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 17px 16px;
  font-size: 14.5px;
  color: rgba(233, 237, 245, 0.9);
  text-decoration: none;
  background: rgba(22, 38, 79, 0.72);
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease);
}

.page-about .about-lead-out-link:hover,
.page-about .about-lead-out-link:focus-visible {
  background: rgba(23, 168, 139, 0.2);
  color: var(--paper);
}

.page-about .about-lead-out-link .mono {
  font-size: 12px;
  color: var(--jade);
}

.page-about .about-lead-out-arrow {
  margin-left: auto;
  color: var(--jade);
  transition: transform 0.18s var(--ease);
}

.page-about .about-lead-out-link:hover .about-lead-out-arrow {
  transform: translateX(4px);
}

/* ---------- 焦点 ---------- */

.page-about a:focus-visible {
  outline: 2px solid var(--jade);
  outline-offset: 3px;
}

/* ---------- 小屏 ---------- */

@media (max-width: 640px) {
  .page-about {
    --about-rail-x: 6px;
    --about-pad: 30px;
  }

  .page-about .about-chapter::before {
    left: 0;
    width: 12px;
    height: 12px;
    border-width: 3px;
  }

  .page-about .about-chapter-head {
    flex-wrap: wrap;
  }

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

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

  .page-about .about-partner-no {
    grid-column: 1;
    grid-row: auto;
    padding-top: 0;
  }

  .page-about .about-partner-list h3,
  .page-about .about-partner-list p {
    grid-column: 1;
  }

  .page-about .about-legend-item {
    grid-template-columns: 16px minmax(0, 1fr);
  }
}

/* ---------- 中大屏 ---------- */

@media (min-width: 720px) {
  .page-about .about-teams {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-about .about-rhythm-item {
    padding: 22px 20px 24px;
  }

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

@media (min-width: 860px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-commit-item {
    grid-template-columns: 160px minmax(0, 1fr);
    column-gap: 24px;
    align-items: baseline;
    padding: 19px 0;
  }
}

@media (min-width: 1000px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(300px, 0.88fr);
    align-items: end;
  }

  .page-about .about-figures {
    align-self: stretch;
  }
}

@media (min-width: 1080px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(40px, 5vw, 78px);
  }

  .page-about .about-rail-col {
    position: sticky;
    top: 118px;
    align-self: start;
  }

  .page-about .about-rail {
    display: block;
    overflow: visible;
    padding-bottom: 0;
    padding-left: 18px;
    border-left: 2px solid rgba(34, 55, 107, 0.28);
  }

  .page-about .about-rail-title {
    display: block;
    margin: 0 0 14px;
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.12em;
    color: var(--muted);
  }

  .page-about .about-rail-list {
    display: grid;
    gap: 4px;
  }

  .page-about .chapter-rail-link {
    display: flex;
    width: 100%;
    padding: 8px 12px;
    font-size: 14px;
    border-color: transparent;
  }
}

@media (min-width: 1200px) {
  .page-about .about-rhythm {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

/* ---------- 动效降级 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .about-stage,
  .page-about .about-rhythm-item,
  .page-about .about-chapter::before,
  .page-about .chapter-rail-link,
  .page-about .about-lead-out-link,
  .page-about .about-lead-out-arrow,
  .page-about .about-inline-note a {
    transition: none;
  }

  .page-about .about-stage:hover,
  .page-about .about-rhythm-item:hover {
    transform: none;
  }

  .page-about .about-chapter:hover::before {
    transform: none;
  }

  .page-about .about-lead-out-link:hover .about-lead-out-arrow {
    transform: none;
  }
}