.page-about {
  --about-num-col: 168px;
  background: var(--ink-900);
  color: var(--paper-50);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.85;
  overflow-x: hidden;
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0;
}

.page-about p {
  margin: 0 0 14px;
}

/* 面包屑 */
.page-about .breadcrumb {
  padding: 20px 0 0;
  margin: 0;
  font-size: 13px;
  color: var(--mist-300);
}

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

.page-about .breadcrumb li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-about .breadcrumb li + li::before {
  content: "/";
  color: var(--signal-500);
}

.page-about .breadcrumb a {
  color: var(--mist-300);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--white);
  border-bottom-color: var(--signal-500);
}

.page-about .breadcrumb [aria-current="page"] {
  color: var(--white);
}

/* 首屏 */
.page-about .about-hero {
  padding: 24px 0 0;
}

.page-about .about-hero-inner {
  display: grid;
  gap: 36px;
  padding: 28px 0 44px;
}

.page-about .about-hero .label {
  color: var(--celadon-400);
}

.page-about h1 {
  font-size: clamp(34px, 7.2vw, 64px);
  line-height: 1.04;
  color: var(--white);
  margin: 12px 0 18px;
  max-width: 15em;
  overflow-wrap: break-word;
}

.page-about .about-hero-lead {
  max-width: 30em;
  color: var(--mist-300);
  margin: 0 0 24px;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* 数据条 */
.page-about .about-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-stats li {
  display: grid;
  gap: 2px;
  padding: 12px 0 12px 14px;
  border-top: 2px solid var(--ink-700);
}

.page-about .stat-num {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 38px;
  line-height: 1;
  color: var(--white);
  font-variant-numeric: tabular-nums;
}

.page-about .stat-num small {
  font-size: 18px;
  color: var(--signal-500);
  margin-left: 3px;
}

.page-about .stat-label {
  font-size: 13px;
  line-height: 1.55;
  color: var(--mist-300);
}

/* 图片容器 */
.page-about .about-fig {
  margin: 0;
  border: 2px solid var(--ink-700);
  background: var(--ink-800);
  box-shadow: var(--shadow-hard);
}

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

.page-about .about-fig figcaption {
  padding: 12px 16px;
  border-top: 2px solid var(--ink-700);
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist-300);
}

.page-about .about-fig--hero {
  margin-bottom: 44px;
}

/* 章节通用 */
.page-about .about-section {
  border-top: 2px solid var(--ink-700);
  padding: 56px 0;
}

.page-about .about-head {
  max-width: 40em;
  margin: 0 0 36px;
}

.page-about .about-head .label {
  margin-bottom: 10px;
}

.page-about .about-head h2 {
  font-size: clamp(28px, 4.6vw, 48px);
  line-height: 1.1;
  color: var(--white);
  margin: 0 0 14px;
}

.page-about .about-head-lead {
  max-width: 32em;
  color: var(--mist-300);
  margin: 0;
}

/* 阶段 */
.page-about .stage-list {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .stage {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  gap: 18px;
  padding-bottom: 44px;
}

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

.page-about .stage-num {
  position: relative;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 42px;
  line-height: 0.9;
  letter-spacing: -0.04em;
  font-variant-numeric: tabular-nums;
  color: transparent;
  -webkit-text-stroke: 1px rgba(200, 214, 226, 0.55);
}

.page-about .stage--current .stage-num {
  color: var(--signal-500);
  -webkit-text-stroke-color: var(--signal-500);
}

.page-about .stage-kicker {
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist-300);
  margin: 0 0 8px;
}

.page-about .stage--current .stage-kicker {
  color: var(--signal-500);
}

.page-about .stage-title {
  font-size: clamp(22px, 3.4vw, 32px);
  line-height: 1.2;
  color: var(--white);
  margin: 0 0 10px;
}

.page-about .stage-text {
  max-width: 34em;
  color: var(--paper-50);
  margin: 0 0 14px;
}

.page-about .stage-more {
  max-width: 34em;
  border-top: 2px solid var(--ink-700);
}

.page-about .stage-more summary {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 0;
  cursor: pointer;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--celadon-400);
}

.page-about .stage-more summary::-webkit-details-marker {
  display: none;
}

.page-about .stage-more summary::before {
  content: "+";
  font-family: var(--font-display);
  font-size: 20px;
  line-height: 1;
  color: var(--celadon-400);
}

.page-about .stage-more[open] summary {
  color: var(--white);
}

.page-about .stage-more[open] summary::before {
  content: "\2212";
}

.page-about .stage-more ul {
  list-style: none;
  margin: 0;
  padding: 0 0 10px;
  display: grid;
  gap: 8px;
}

.page-about .stage-more li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--mist-300);
}

.page-about .stage-more li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 9px;
  height: 2px;
  background: var(--celadon-400);
}

/* 三组分工 */
.page-about .team-layout {
  display: grid;
  gap: 32px;
}

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

.page-about .team-block {
  background: var(--ink-800);
  border: 2px solid var(--ink-700);
  border-top-width: 8px;
  padding: 16px;
  transition: transform 180ms var(--ease), box-shadow 180ms var(--ease);
}

.page-about .team-block:hover,
.page-about .team-block:focus-within {
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-hard);
}

.page-about .team-block--monitor {
  border-top-color: var(--celadon-400);
}

.page-about .team-block--editor {
  border-top-color: var(--signal-500);
}

.page-about .team-block--support {
  border-top-color: var(--mist-300);
}

.page-about .team-block h3 {
  font-size: 20px;
  line-height: 1.25;
  color: var(--white);
  margin: 0 0 8px;
}

.page-about .team-block p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist-300);
  margin: 0 0 10px;
}

.page-about .team-block .team-meta {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--paper-200);
  border-top: 2px solid var(--ink-700);
  padding-top: 8px;
}

.page-about .team-block--monitor .team-meta {
  color: var(--celadon-400);
}

.page-about .team-block--editor .team-meta {
  color: var(--signal-500);
}

.page-about .about-fig--team {
  align-self: start;
}

/* 版本节奏 */
.page-about .version-layout {
  display: grid;
  gap: 32px;
  margin-bottom: 36px;
}

.page-about .version-list {
  margin: 0;
  display: grid;
  gap: 0;
}

.page-about .version-item {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-top: 2px solid var(--ink-700);
}

.page-about .version-item:last-child {
  border-bottom: 2px solid var(--ink-700);
}

.page-about .version-item dt {
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--celadon-400);
}

.page-about .version-item dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist-300);
}

.page-about .version-item dd strong {
  font-family: var(--font-display);
  font-size: 22px;
  letter-spacing: 0;
  color: var(--white);
  margin-right: 6px;
}

.page-about .ruler-wrap {
  border-top: 2px solid var(--ink-700);
  padding-top: 24px;
}

.page-about .ruler {
  display: flex;
  align-items: flex-end;
  gap: 3px;
  height: 76px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--ink-700);
}

.page-about .tick {
  position: relative;
  flex: 1 1 0;
  min-width: 0;
  height: 30px;
  background: var(--ink-700);
  transition: background 180ms var(--ease), transform 180ms var(--ease);
}

.page-about .tick:hover {
  background: var(--signal-500);
  transform: translateY(-5px);
}

.page-about .tick--now {
  height: 54px;
  background: var(--signal-500);
}

.page-about .tick--now:hover {
  background: var(--signal-700);
}

.page-about .tick::after {
  content: attr(title);
  position: absolute;
  left: 50%;
  bottom: calc(100% + 10px);
  transform: translateX(-50%);
  white-space: nowrap;
  background: var(--paper-50);
  color: var(--ink-900);
  font-size: 12px;
  line-height: 1.4;
  letter-spacing: 0;
  padding: 4px 8px;
  border: 2px solid var(--ink-900);
  opacity: 0;
  pointer-events: none;
  transition: opacity 180ms var(--ease);
  z-index: 4;
}

.page-about .tick:hover::after {
  opacity: 1;
}

.page-about .ruler-note {
  margin: 14px 0 0;
  font-size: 13px;
  line-height: 1.65;
  color: var(--mist-300);
  max-width: 40em;
}

/* 服务对象（浅色区） */
.page-about .about-audience {
  background: var(--paper-50);
  color: var(--ink-900);
  border-top: 2px solid var(--ink-900);
  border-bottom: 2px solid var(--ink-900);
}

.page-about .about-audience .about-head .label {
  color: var(--celadon-700);
}

.page-about .about-audience .about-head h2 {
  color: var(--ink-900);
}

.page-about .about-audience .about-head-lead {
  color: var(--ink-700);
}

.page-about .aud-grid {
  display: grid;
  gap: 16px;
}

.page-about .aud-card {
  display: grid;
  gap: 8px;
  align-content: start;
  background: var(--paper-200);
  border: 2px solid var(--ink-900);
  box-shadow: var(--shadow-hard-paper);
  padding: 18px;
}

.page-about .aud-index {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 28px;
  line-height: 1;
  color: var(--signal-700);
  font-variant-numeric: tabular-nums;
}

.page-about .aud-card h3 {
  font-size: 21px;
  line-height: 1.25;
  color: var(--ink-900);
  margin: 0;
}

.page-about .aud-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-700);
}

.page-about .aud-note {
  margin: 26px 0 0;
  padding-top: 14px;
  border-top: 2px solid var(--ink-900);
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-700);
  max-width: 46em;
}

/* 备案与联系 */
.page-about .reach-layout {
  display: grid;
  gap: 32px;
}

.page-about .reach-copy .label {
  color: var(--celadon-400);
  margin-bottom: 10px;
}

.page-about .reach-copy h2 {
  font-size: clamp(26px, 4.2vw, 42px);
  line-height: 1.12;
  color: var(--white);
  margin: 0 0 14px;
}

.page-about .reach-copy p {
  max-width: 32em;
  color: var(--mist-300);
  margin: 0 0 22px;
}

.page-about .reach-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .reach-cards {
  display: grid;
  gap: 12px;
  align-content: start;
}

.page-about .reach-card {
  display: grid;
  gap: 4px;
  background: var(--ink-800);
  border: 2px solid var(--ink-700);
  box-shadow: var(--shadow-hard);
  padding: 14px 16px;
}

.page-about .rc-label {
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--celadon-400);
}

.page-about .rc-value {
  font-size: 16px;
  line-height: 1.6;
  color: var(--white);
  overflow-wrap: anywhere;
}

.page-about .rc-value--email {
  font-family: var(--font-body);
  font-size: 15px;
}

.page-about .rc-note {
  font-size: 13px;
  line-height: 1.65;
  color: var(--mist-300);
}

.page-about .reach-card--icp {
  border-color: var(--signal-500);
}

.page-about .reach-card--icp .rc-label {
  color: var(--signal-500);
}

/* 响应式 */
@media (min-width: 600px) {
  .page-about .aud-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    border-left: 2px solid var(--ink-700);
  }

  .page-about .about-stats li {
    padding-left: 18px;
  }

  .page-about .stat-num {
    font-size: 44px;
  }

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

  .page-about .reach-card:nth-child(3) {
    grid-column: 1 / -1;
  }
}

@media (min-width: 860px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 56px;
    align-items: start;
    padding: 48px 0 56px;
  }

  .page-about .about-section {
    padding: 88px 0;
  }

  .page-about .about-head {
    margin-bottom: 52px;
  }

  .page-about .stage-list::before {
    content: "";
    position: absolute;
    left: calc(var(--about-num-col) - 1px);
    top: 14px;
    bottom: 12px;
    width: 2px;
    background: var(--ink-700);
  }

  .page-about .stage {
    grid-template-columns: var(--about-num-col) minmax(0, 1fr);
    gap: 40px;
    padding-bottom: 96px;
  }

  .page-about .stage-num {
    font-size: 128px;
    -webkit-text-stroke: 2px rgba(200, 214, 226, 0.4);
    padding-right: 20px;
  }

  .page-about .stage--current .stage-num {
    -webkit-text-stroke-color: var(--signal-500);
  }

  .page-about .stage-num::after {
    content: "";
    position: absolute;
    right: -5px;
    top: 22px;
    width: 10px;
    height: 10px;
    background: var(--ink-700);
  }

  .page-about .stage--current .stage-num::after {
    background: var(--signal-500);
  }

  .page-about .team-layout {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .team-blocks {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
  }

  .page-about .version-layout {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: 48px;
    align-items: center;
  }

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

  .page-about .reach-layout {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 48px;
    align-items: start;
  }
}

@media (min-width: 960px) {
  .page-about .about-stats {
    grid-template-columns: minmax(0, 1fr);
    border-left: 2px solid var(--ink-700);
  }

  .page-about .stat-num {
    font-size: 48px;
  }

  .page-about .aud-card {
    padding: 22px;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .team-block,
  .page-about .tick,
  .page-about .tick::after {
    transition: none;
  }

  .page-about .team-block:hover,
  .page-about .team-block:focus-within {
    transform: none;
  }

  .page-about .tick:hover {
    transform: none;
  }
}