.page-about {
  background: var(--ink);
  color: var(--paper);
  overflow-x: hidden;
}

.page-about .about-hero {
  padding: 28px 0 52px;
  border-bottom: var(--line);
  background:
    radial-gradient(120% 90% at 90% 0%, rgba(20, 184, 196, 0.16) 0%, rgba(20, 184, 196, 0) 58%),
    radial-gradient(90% 70% at 0% 100%, rgba(245, 197, 24, 0.07) 0%, rgba(245, 197, 24, 0) 60%),
    var(--ink);
}

.page-about .breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0 0 30px;
  padding: 0;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .breadcrumbs li + li::before {
  content: "/";
  margin-right: 6px;
  color: var(--grid);
}

.page-about .breadcrumbs a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .breadcrumbs a:hover {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

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

.page-about .about-hero-grid {
  display: grid;
  gap: 36px;
}

.page-about .about-hero-main .eyebrow {
  margin: 0;
}

.page-about .about-hero-main h1 {
  margin: 12px 0 20px;
  font-size: clamp(30px, 7vw, 50px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.02em;
  max-width: 15em;
}

.page-about .about-hero-main .lead {
  margin: 0 0 28px;
  max-width: 640px;
  font-size: 17px;
  line-height: 1.85;
  color: #CFDCEA;
}

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

.page-about .about-manifest {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 0;
  border-top: var(--line);
  border-left: var(--line);
}

.page-about .manifest-item {
  padding: 18px 16px;
  border-right: var(--line);
  border-bottom: var(--line);
}

.page-about .manifest-item dt {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .manifest-item dd {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  color: var(--paper);
  display: flex;
  align-items: baseline;
  gap: 6px;
  flex-wrap: wrap;
}

.page-about .manifest-item dd .stat-num {
  font-size: 26px;
  line-height: 1;
}

/* 版本节点横向色带 */
.page-about .about-band {
  border-bottom: var(--line);
  background: linear-gradient(90deg, rgba(20, 184, 196, 0.15) 0%, rgba(20, 184, 196, 0.04) 42%, rgba(245, 197, 24, 0.12) 100%);
}

.page-about .band-nodes {
  display: grid;
  grid-template-columns: 1fr;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .band-node {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 0;
  border-bottom: 1px solid rgba(36, 64, 107, 0.75);
}

.page-about .band-node:last-child {
  border-bottom: 0;
}

.page-about .band-ver {
  flex: none;
  min-width: 46px;
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--cyan);
}

.page-about .band-node--now .band-ver {
  color: var(--yellow);
}

.page-about .band-text {
  font-size: 15px;
  line-height: 1.7;
  color: #CFDCEA;
}

/* 正文双栏 */
.page-about .about-body {
  display: grid;
  gap: 40px;
  padding-top: 52px;
  padding-bottom: 40px;
}

.page-about .about-toc .toc-title {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.page-about .about-toc ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
  border-left: var(--line);
}

.page-about .about-toc a {
  display: block;
  padding: 9px 14px;
  margin-left: -1px;
  border-left: 2px solid var(--grid);
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about .about-toc a:hover {
  color: var(--paper);
  border-left-color: var(--cyan-soft);
}

.page-about .about-toc a[aria-current="true"] {
  color: var(--paper);
  border-left-color: var(--cyan);
  background: rgba(20, 184, 196, 0.09);
}

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

.page-about .about-section {
  padding-bottom: 48px;
  margin-bottom: 48px;
  border-bottom: var(--line);
}

.page-about .about-section:last-child {
  margin-bottom: 0;
  padding-bottom: 8px;
  border-bottom: 0;
}

.page-about .section-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 22px;
}

.page-about .section-index {
  flex: none;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .section-head h2 {
  margin: 0;
  font-size: clamp(21px, 4.6vw, 30px);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: -0.01em;
}

.page-about .about-section p {
  max-width: 720px;
  margin: 0 0 1.2em;
  font-size: 17px;
  line-height: 1.85;
  color: #CFDCEA;
}

.page-about .about-section p:last-of-type {
  margin-bottom: 0;
}

/* 节奏数据条 */
.page-about .rhythm-strip {
  display: grid;
  grid-template-columns: 1fr;
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  border-top: var(--line);
  border-left: var(--line);
}

.page-about .rhythm-strip li {
  padding: 16px 16px 18px;
  border-right: var(--line);
  border-bottom: var(--line);
  font-size: 13px;
  letter-spacing: 0.05em;
  color: var(--muted);
}

.page-about .rhythm-strip .mono-num {
  display: block;
  margin-bottom: 8px;
  font-size: 28px;
  font-weight: 700;
  line-height: 1;
  color: var(--yellow);
}

/* 版本演进轴 */
.page-about .version-axis {
  list-style: none;
  margin: 0 0 32px;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
}

.page-about .axis-node {
  position: relative;
  padding: 0 0 24px 26px;
  border-left: var(--line);
}

.page-about .axis-node:last-child {
  padding-bottom: 8px;
}

.page-about .axis-node::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  background: var(--ink);
  border: 2px solid var(--cyan);
  transform: rotate(45deg);
}

.page-about .axis-node.is-current::before {
  border-color: var(--yellow);
  background: var(--yellow);
}

.page-about .axis-ver {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 21px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--cyan);
}

.page-about .axis-node.is-current .axis-ver {
  color: var(--yellow);
}

.page-about .axis-desc {
  margin: 0;
  max-width: 260px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* 团队网格 */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  margin: 26px 0 32px;
  border-top: var(--line);
  border-left: var(--line);
}

.page-about .team-card {
  padding: 24px 20px 26px;
  border-right: var(--line);
  border-bottom: var(--line);
  background: linear-gradient(180deg, rgba(20, 41, 74, 0.55) 0%, rgba(11, 26, 51, 0) 100%);
}

.page-about .team-num {
  display: block;
  margin-bottom: 14px;
  font-size: 42px;
  font-weight: 700;
  line-height: 1;
  color: var(--yellow);
}

.page-about .team-card h3 {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.page-about .team-card p {
  margin: 0;
  max-width: none;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--muted);
}

/* 协作区 */
.page-about .collab-grid {
  display: grid;
  gap: 30px;
  align-items: start;
}

.page-about .collab-copy p {
  max-width: 640px;
}

.page-about .collab-stats {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  border-top: var(--line);
}

.page-about .collab-stats li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 14px 0;
  border-bottom: var(--line);
  font-size: 14.5px;
  line-height: 1.7;
  color: #CFDCEA;
}

.page-about .collab-stats .stat-num {
  flex: none;
  font-size: 26px;
  line-height: 1;
}

/* 归档区 */
.page-about .archive-grid {
  display: grid;
  gap: 28px;
  align-items: center;
  margin: 4px 0 28px;
}

.page-about .archive-tags {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--line);
}

.page-about .archive-tags li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 16px 0;
  border-bottom: var(--line);
  font-size: 14.5px;
  line-height: 1.75;
  color: #CFDCEA;
}

.page-about .archive-tags .tag {
  flex: none;
}

/* 下一赛季清单 */
.page-about .next-list {
  list-style: none;
  margin: 4px 0 0;
  padding: 0;
  counter-reset: next;
  border-top: var(--line);
}

.page-about .next-list li {
  position: relative;
  counter-increment: next;
  padding: 24px 0 24px 50px;
  border-bottom: var(--line);
}

.page-about .next-list li::before {
  content: counter(next, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 27px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--orange);
}

.page-about .next-list h3 {
  margin: 0 0 8px;
  font-size: 17.5px;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .next-list p {
  margin: 0;
  max-width: 640px;
  font-size: 15px;
  line-height: 1.82;
  color: var(--muted);
}

/* 收尾 */
.page-about .about-cta {
  border-top: var(--line);
  padding: 48px 0 60px;
  background:
    linear-gradient(180deg, rgba(20, 184, 196, 0.12) 0%, rgba(11, 26, 51, 0) 70%),
    var(--ink-2);
}

.page-about .about-cta-inner {
  display: grid;
  gap: 26px;
  align-items: center;
}

.page-about .about-cta h2 {
  margin: 0 0 12px;
  font-size: clamp(21px, 4.4vw, 29px);
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.page-about .about-cta p {
  margin: 0;
  max-width: 640px;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--muted);
}

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

.page-about .img-frame {
  margin: 32px 0 0;
}

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

.page-about .img-frame figcaption {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .collab-grid .img-frame,
.page-about .archive-grid .img-frame {
  margin: 0;
}

/* 中等屏 */
@media (min-width: 640px) {
  .page-about .about-hero {
    padding: 34px 0 64px;
  }

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

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

  .page-about .band-node {
    flex-direction: column;
    gap: 8px;
    padding: 20px 20px 22px;
    border-bottom: 0;
    border-right: 1px solid rgba(36, 64, 107, 0.75);
  }

  .page-about .band-node:last-child {
    border-right: 0;
    padding-right: 0;
  }

  .page-about .band-node:first-child {
    padding-left: 0;
  }

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

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

  .page-about .axis-node {
    padding: 30px 22px 0 0;
    border-left: 0;
    border-top: 1px solid var(--grid);
  }

  .page-about .axis-node:last-child {
    padding-bottom: 0;
    padding-right: 0;
  }

  .page-about .axis-node::before {
    left: 0;
    top: -5px;
  }
}

/* 桌面：固定章节目录 + 正文长卷 */
@media (min-width: 1000px) {
  .page-about .about-hero {
    padding: 40px 0 76px;
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    gap: 64px;
    align-items: start;
  }

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

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

  .page-about .about-body {
    grid-template-columns: 216px minmax(0, 1fr);
    gap: 64px;
    padding-top: 68px;
    padding-bottom: 56px;
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
  }

  .page-about .about-section {
    padding-bottom: 60px;
    margin-bottom: 60px;
  }

  .page-about .collab-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 44px;
    align-items: center;
  }

  .page-about .archive-grid {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 44px;
  }

  .page-about .about-cta-inner {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 48px;
  }

  .page-about .about-cta-actions {
    justify-content: flex-end;
  }
}

@media (min-width: 1200px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  }

  .page-about .axis-desc {
    max-width: 240px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .breadcrumbs a,
  .page-about .about-toc a {
    transition: none;
  }
}