.page-about {
  --about-rail: 176px;
}

.page-about .about-hero {
  padding: clamp(18px, 3.6vw, 34px) 0 clamp(26px, 4.6vw, 42px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(29px, 6vw, 48px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--paper);
  margin: 14px 0 16px;
  max-width: 22ch;
}

.page-about .about-hero .lede {
  max-width: 60ch;
  margin: 0;
}

.page-about .about-hero__note {
  margin: 16px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  line-height: 1.9;
  color: var(--muted);
  max-width: 58ch;
}

/* 全宽数据条 */
.page-about .numstrip {
  background:
    linear-gradient(180deg, rgba(34, 232, 200, 0.1), rgba(6, 17, 14, 0) 72%),
    var(--panel-deep);
  border-bottom: 1px solid var(--line);
}

.page-about .numstrip__inner {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 16px;
  padding: clamp(22px, 4.4vw, 38px) 0;
}

.page-about .num-cell {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-left: 14px;
  border-left: 2px solid var(--cyan);
  min-width: 0;
}

.page-about .num-value {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(36px, 8vw, 60px);
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .num-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.07em;
  color: var(--muted);
}

/* 主体：粘性目录 + 内容流 */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 46px);
  padding: clamp(30px, 5.4vw, 60px) 0 clamp(48px, 8vw, 92px);
}

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

.page-about .anchor-rail .toc {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: thin;
}

.page-about .anchor-rail .toc__link {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.07em;
  color: var(--muted);
  text-decoration: none;
  padding: 6px 10px;
  border-left: 2px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .anchor-rail .toc__link:hover {
  color: var(--cyan);
}

.page-about .anchor-rail .toc__link[aria-current="true"] {
  color: var(--cyan);
  border-left-color: var(--orange);
}

.page-about .about-flow {
  min-width: 0;
}

/* 章节 */
.page-about .chapter + .chapter {
  margin-top: clamp(44px, 7.5vw, 84px);
}

.page-about .chapter__head {
  position: relative;
  padding-top: 18px;
  margin-bottom: clamp(16px, 2.6vw, 24px);
}

.page-about .chapter__head::before,
.page-about .chapter__head::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  height: 2px;
}

.page-about .chapter__head::before {
  width: 100%;
  background: var(--line);
}

.page-about .chapter__head::after {
  width: 68px;
  background: var(--cyan);
}

.page-about .chapter__head h2 {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(23px, 4.2vw, 34px);
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--paper);
  margin: 8px 0 0;
  max-width: 26ch;
}

/* 档案区块纸卡 */
.page-about .archive-cards {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin: clamp(20px, 3vw, 28px) 0;
}

.page-about .archive-card {
  position: relative;
  padding: 24px 18px 20px;
  min-width: 0;
}

.page-about .archive-card h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--paper-ink);
}

.page-about .archive-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--paper-ink);
  opacity: 0.82;
}

/* 覆盖版图 */
.page-about .cover-visual {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  align-items: center;
  margin: 8px 0 clamp(18px, 3vw, 26px);
}

.page-about .fan {
  width: 100%;
  max-width: 300px;
  height: auto;
  display: block;
  margin: 0 auto;
}

.page-about .fan-legend {
  display: grid;
  gap: 12px;
  min-width: 0;
}

.page-about .fan-legend__row {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--text);
}

.page-about .fan-legend__dot {
  flex: none;
  width: 12px;
  height: 12px;
  border-radius: 2px;
  background: var(--cyan);
}

.page-about .fan-legend__dot--b {
  opacity: 0.72;
}

.page-about .fan-legend__dot--c {
  opacity: 0.48;
}

.page-about .fan-legend__dot--d {
  opacity: 0.28;
}

.page-about .city-index {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 18px 0 clamp(20px, 3vw, 28px);
  padding: 0;
}

.page-about .city-chip {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.07em;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  padding: 6px 12px;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .city-chip:hover {
  color: var(--cyan);
  border-color: var(--cyan);
}

.page-about .level-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 0 0 clamp(22px, 3.4vw, 30px);
}

.page-about .level-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  padding: 18px;
  min-width: 0;
  transition: border-color 0.18s var(--ease), transform 0.18s var(--ease);
}

.page-about .level-card:hover {
  border-color: var(--cyan);
  transform: translateY(-3px);
}

.page-about .level-card__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .level-card h3 {
  margin: 8px 0 8px;
  font-size: 19px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .level-card p:last-child {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
}

/* 图片容器 */
.page-about .media {
  margin: 0;
  min-width: 0;
}

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

.page-about .cover-media {
  margin-bottom: clamp(8px, 1.6vw, 14px);
}

/* 流水线 */
.page-about .pipeline {
  list-style: none;
  margin: clamp(18px, 3vw, 26px) 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .pipe-node {
  position: relative;
  min-width: 0;
  padding: 0 0 26px 26px;
  border-left: 2px solid var(--line);
  transition: border-color 0.18s var(--ease);
}

.page-about .pipe-node::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 4px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(34, 232, 200, 0.14);
}

.page-about .pipe-node:hover {
  border-left-color: var(--cyan);
}

.page-about .pipe-node:hover .pipe-node__out {
  border-color: var(--orange);
  color: var(--orange);
}

.page-about .pipe-node__no {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 30px;
  line-height: 1;
  color: var(--cyan-soft);
  font-variant-numeric: tabular-nums;
}

.page-about .pipe-node__title {
  margin: 8px 0 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .pipe-node p {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--text);
}

.page-about .pipe-node__out {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan-soft);
  border: 1px dashed var(--line);
  border-radius: var(--radius-pill);
  padding: 5px 11px;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .pipe-media {
  margin-bottom: clamp(18px, 3vw, 26px);
}

/* 版本时间轴 */
.page-about .versions-media {
  margin-bottom: clamp(20px, 3.4vw, 30px);
}

.page-about .versions {
  list-style: none;
  margin: 0;
  padding: 0 0 0 0;
  border-left: 2px solid var(--line);
}

.page-about .version {
  position: relative;
  min-width: 0;
  padding: 0 0 14px 22px;
  margin-right: 2px;
}

.page-about .version::before {
  content: "";
  position: absolute;
  left: -8px;
  top: 16px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--paper);
  border: 3px solid var(--orange);
  box-sizing: border-box;
}

.page-about .version details {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  padding: 14px 16px;
  transition: border-color 0.18s var(--ease);
}

.page-about .version details:hover {
  border-color: var(--cyan-soft);
}

.page-about .version details[open] {
  border-color: var(--cyan);
}

.page-about .version summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 12px;
  cursor: pointer;
  list-style: none;
  outline-offset: 3px;
}

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

.page-about .version__no {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 22px;
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .version__title {
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .version__cap {
  flex-basis: 100%;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  line-height: 1.7;
  color: var(--orange);
}

.page-about .version__body {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  font-size: 15px;
  line-height: 1.72;
  color: var(--text);
}

/* 团队 */
.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: clamp(20px, 3vw, 28px) 0;
}

.page-about .team-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  padding: 16px 18px;
  min-width: 0;
  border-top: 2px solid var(--cyan-soft);
}

.page-about .team-card__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .team-card h3 {
  margin: 8px 0 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .team-card p:last-child {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--text);
}

/* 合作 */
.page-about .partner-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .partner-card {
  background: var(--panel-deep);
  border: 1px solid var(--line);
  border-left: 3px solid var(--orange);
  border-radius: var(--radius-card);
  padding: 16px 18px;
  min-width: 0;
}

.page-about .partner-card__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .partner-card h3 {
  margin: 8px 0 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .partner-card p:last-child {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--text);
}

/* 结尾行动区 */
.page-about .cta-band {
  margin-top: clamp(40px, 7vw, 76px);
  padding: clamp(22px, 4.4vw, 38px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  background:
    linear-gradient(135deg, rgba(34, 232, 200, 0.14), rgba(6, 17, 14, 0) 62%),
    var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
}

.page-about .cta-band h2 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(21px, 3.4vw, 28px);
  line-height: 1.3;
  color: var(--paper);
}

.page-about .cta-band p {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--text);
}

.page-about .cta-band__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

/* 平板 */
@media (min-width: 720px) {
  .page-about .numstrip__inner {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 26px 20px;
  }

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

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

  .page-about .cta-band {
    grid-template-columns: 7fr 5fr;
    align-items: center;
  }
}

/* 桌面：左目录右内容，非对称分栏 */
@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(28px, 3.4vw, 52px);
  }

  .page-about .anchor-rail {
    position: sticky;
    top: 104px;
  }

  .page-about .anchor-rail .toc {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .cover-visual {
    grid-template-columns: 5fr 7fr;
    gap: 32px;
  }

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

  .page-about .archive-cards {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .archive-card:nth-child(2) {
    margin-top: 22px;
  }

  .page-about .archive-card:nth-child(3) {
    margin-top: 8px;
  }

  .page-about .archive-card:nth-child(4) {
    margin-top: 30px;
  }

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

/* 宽屏：流水线转横向节点条 */
@media (min-width: 1080px) {
  .page-about .pipeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0 24px;
  }

  .page-about .pipe-node {
    border-left: 0;
    border-top: 2px solid var(--line);
    padding: 26px 0 0;
  }

  .page-about .pipe-node::before {
    left: 0;
    top: -7px;
  }

  .page-about .pipe-node:hover {
    border-left-color: transparent;
    border-top-color: var(--cyan);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .level-card,
  .page-about .pipe-node,
  .page-about .pipe-node__out,
  .page-about .version details,
  .page-about .city-chip,
  .page-about .anchor-rail .toc__link {
    transition: none;
  }

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