.page-about {
  --ba-rail: 176px;
  --ba-slice-gap: clamp(20px, 3vw, 44px);
  --ba-band-y: clamp(52px, 7vw, 92px);
  display: block;
}

/* ---------- 首屏 ---------- */
.page-about .ba-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(32px, 5vw, 56px) 0 clamp(36px, 5vw, 64px);
  border-bottom: 1px solid var(--line);
}

.page-about .ba-hero::before {
  content: "";
  position: absolute;
  top: -8%;
  right: -14%;
  width: min(720px, 86vw);
  height: 120%;
  z-index: -1;
  background: linear-gradient(155deg, rgba(27, 140, 119, 0.34), rgba(4, 13, 11, 0.05) 68%);
  clip-path: polygon(30% 0, 100% 0, 100% 100%, 0 72%);
}

.page-about .ba-hero::after {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--orange) 52%, rgba(255, 122, 47, 0));
  opacity: 0.75;
}

.page-about .ba-hero .breadcrumb {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .ba-hero-grid {
  display: grid;
  gap: 28px;
}

.page-about .ba-hero h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(30px, 5.4vw, 56px);
  line-height: 1.08;
  letter-spacing: -0.01em;
  color: var(--chalk);
  margin: 12px 0 18px;
  max-width: 18ch;
}

.page-about .ba-hero .lede {
  max-width: 60ch;
  color: var(--text-soft);
  line-height: 1.85;
}

.page-about .ba-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .ba-namecard {
  background: var(--glass);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-card);
  padding: 22px 22px 12px;
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.page-about .ba-namecard-title {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.14em;
  color: var(--cyan);
  margin-bottom: 14px;
}

.page-about .ba-namecard-list {
  margin: 0;
}

.page-about .ba-namecard-list > div {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 10px 0;
  border-top: 1px solid var(--line);
}

.page-about .ba-namecard-list dt {
  font-size: 13.5px;
  color: var(--gray);
}

.page-about .ba-namecard-list dd {
  margin: 0;
  font-size: 14px;
  color: var(--chalk);
  text-align: right;
}

.page-about .ba-stats {
  list-style: none;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  overflow: hidden;
}

.page-about .ba-stat {
  background: var(--ink-900);
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .ba-stat-num {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 3.6vw, 36px);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .ba-stat:nth-child(2) .ba-stat-num {
  color: var(--orange);
}

.page-about .ba-stat-label {
  font-size: 13px;
  color: var(--gray);
}

/* ---------- 横向切片与左窄栏 ---------- */
.page-about .ba-band {
  padding: var(--ba-band-y) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .ba-band--tint {
  background: var(--ink-800);
}

.page-about .ba-band--deep {
  background: linear-gradient(180deg, #06110E, var(--ink-900) 76%);
}

.page-about .ba-slice {
  display: grid;
  gap: 22px;
}

.page-about .ba-rail {
  border-left: 2px solid var(--cyan);
  padding-left: 14px;
}

.page-about .ba-rail-no {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .ba-rail-label {
  font-family: var(--font-display);
  font-size: 15px;
  letter-spacing: 0.14em;
  color: var(--chalk);
  margin-top: 6px;
}

.page-about .ba-rail-note {
  margin-top: 8px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--gray);
}

.page-about .ba-body {
  min-width: 0;
}

.page-about .ba-body > .section-title {
  margin-bottom: 18px;
  max-width: 24ch;
}

.page-about .ba-body .prose {
  max-width: 68ch;
}

.page-about .ba-lead {
  max-width: 63ch;
  color: var(--text-soft);
  line-height: 1.85;
  margin-bottom: 24px;
}

.page-about .ba-tags {
  margin-top: 22px;
}

/* ---------- 团队 ---------- */
.page-about .ba-team-grid {
  display: grid;
  gap: 26px;
  align-items: center;
}

.page-about .ba-ring-figure {
  margin: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.page-about .ba-ring {
  width: 100%;
  max-width: 218px;
  height: auto;
  display: block;
}

.page-about .ba-ring-track {
  fill: none;
  stroke: rgba(124, 139, 135, 0.18);
  stroke-width: 16;
}

.page-about .ba-ring-seg {
  fill: none;
  stroke-width: 16;
  transition: stroke-width 0.18s ease;
}

.page-about .ba-ring-seg--data {
  stroke: var(--cyan);
}

.page-about .ba-ring-seg--write {
  stroke: var(--orange);
}

.page-about .ba-ring-seg--ops {
  stroke: var(--cyan-deep);
}

.page-about .ba-ring-seg:hover {
  stroke-width: 23;
}

.page-about .ba-ring-num {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 30px;
  fill: var(--chalk);
}

.page-about .ba-ring-unit {
  font-family: var(--font-mono);
  font-size: 12px;
  fill: var(--gray);
}

.page-about .ba-ring-caption {
  font-size: 12.5px;
  color: var(--gray);
  letter-spacing: 0.04em;
}

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

.page-about .ba-legend-item {
  display: grid;
  grid-template-columns: 14px minmax(0, 1fr) auto;
  align-items: center;
  gap: 10px;
  padding: 14px 0;
  border-top: 1px solid var(--line);
  transition: border-color 0.18s ease;
}

.page-about .ba-legend-item:hover {
  border-color: var(--line-strong);
}

.page-about .ba-legend-swatch {
  width: 10px;
  height: 10px;
  border-radius: 3px;
  background: var(--cyan);
}

.page-about .ba-legend-item--write .ba-legend-swatch {
  background: var(--orange);
}

.page-about .ba-legend-item--ops .ba-legend-swatch {
  background: var(--cyan-deep);
}

.page-about .ba-legend-name {
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: 0.04em;
  color: var(--chalk);
}

.page-about .ba-legend-val {
  font-size: 14px;
  color: var(--cyan);
}

.page-about .ba-legend-desc {
  grid-column: 2 / -1;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text-mid);
}

.page-about .ba-media {
  margin: clamp(24px, 3vw, 36px) 0 0;
}

.page-about .ba-media--map {
  aspect-ratio: 12 / 7;
}

/* ---------- 数据条 ---------- */
.page-about .ba-facts {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border-block: 1px solid var(--line);
}

.page-about .ba-fact {
  background: rgba(8, 24, 20, 0.6);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .ba-fact-num {
  font-size: 18px;
  color: var(--cyan);
  letter-spacing: 0.02em;
}

.page-about .ba-fact-label {
  font-size: 12.5px;
  color: var(--gray);
}

/* ---------- 版本标签页 ---------- */
.page-about .ba-tablist {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 26px;
}

.page-about .ba-tab {
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: 0.06em;
  padding: 10px 16px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line-strong);
  background: rgba(18, 48, 38, 0.35);
  color: var(--text-soft);
  cursor: pointer;
  transition: color 0.18s ease, background 0.18s ease, border-color 0.18s ease;
}

.page-about .ba-tab:hover {
  color: var(--chalk);
  border-color: var(--cyan);
}

.page-about .ba-tab[aria-selected="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: #06201A;
  font-weight: 700;
}

.page-about .ba-tab:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 2px;
}

.page-about .ba-panel {
  border-left: 2px solid var(--cyan);
  padding: 2px 0 6px 18px;
}

.page-about .ba-panel-kicker {
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .ba-panel h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(20px, 2.6vw, 26px);
  letter-spacing: 0.01em;
  color: var(--chalk);
  margin: 8px 0 12px;
}

.page-about .ba-panel > p {
  max-width: 62ch;
  color: var(--text-soft);
  line-height: 1.85;
}

.page-about .ba-panel-facts {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  font-size: 13px;
  color: var(--text-mid);
}

.page-about .ba-panel-facts .mono {
  color: var(--amber);
  margin-right: 6px;
}

.page-about .ba-after {
  margin-top: 28px;
  font-size: 14.5px;
  color: var(--text-mid);
  line-height: 1.8;
}

.page-about .ba-after a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 协作节点 ---------- */
.page-about .ba-nodes {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .ba-node {
  border-top: 2px solid var(--line-strong);
  padding-top: 12px;
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.page-about .ba-node:hover,
.page-about .ba-node:focus-within {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .ba-node-code {
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .ba-node-name {
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: 0.04em;
  color: var(--chalk);
  margin: 5px 0 7px;
}

.page-about .ba-node p:last-child {
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-mid);
}

/* ---------- 栏目档案卡 ---------- */
.page-about .ba-lanes {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .ba-lane {
  position: relative;
  overflow: hidden;
  padding: 20px 18px 18px;
  background: rgba(18, 48, 38, 0.4);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
}

.page-about .ba-lane::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, rgba(61, 240, 196, 0.22), rgba(61, 240, 196, 0));
  clip-path: polygon(100% 0, 0 0, 100% 100%);
}

.page-about .ba-lane-no {
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .ba-lane-title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 19px;
  letter-spacing: 0.03em;
  color: var(--chalk);
  margin: 8px 0 10px;
}

.page-about .ba-lane-text {
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--text-mid);
}

.page-about .ba-lane-meta {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--gray);
}

/* ---------- 计划清单 ---------- */
.page-about .ba-plan {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ba-plan-item {
  display: grid;
  gap: 8px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
}

.page-about .ba-plan-item:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .ba-plan-no {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .ba-plan-item h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 19px;
  letter-spacing: 0.02em;
  color: var(--chalk);
}

.page-about .ba-plan-item p:last-child {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-mid);
}

/* ---------- 收尾 ---------- */
.page-about .ba-cta {
  padding: var(--ba-band-y) 0;
  background: linear-gradient(140deg, var(--ink-700), var(--ink-900) 62%);
  border-top: 2px solid var(--cyan);
}

.page-about .ba-cta-inner {
  display: grid;
  gap: 22px;
}

.page-about .ba-cta h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 3.4vw, 36px);
  letter-spacing: 0.01em;
  color: var(--chalk);
  margin-top: 10px;
}

.page-about .ba-cta p {
  max-width: 56ch;
  margin-top: 12px;
  color: var(--text-soft);
  line-height: 1.85;
}

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

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .page-about .ba-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 760px) {
  .page-about .ba-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 820px) {
  .page-about .ba-team-grid {
    grid-template-columns: 240px minmax(0, 1fr);
    gap: 36px;
  }
}

@media (min-width: 900px) {
  .page-about .ba-slice {
    grid-template-columns: var(--ba-rail) minmax(0, 1fr);
    gap: var(--ba-slice-gap);
    align-items: start;
  }

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

  .page-about .ba-cta-inner {
    grid-template-columns: minmax(0, 1.15fr) auto;
    align-items: center;
    gap: 40px;
  }

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

@media (min-width: 960px) {
  .page-about .ba-hero-grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(280px, 0.78fr);
    gap: 48px;
    align-items: start;
  }
}

@media (min-width: 1080px) {
  .page-about .ba-lanes {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ba-plan-item {
    grid-template-columns: 92px minmax(0, 0.9fr) minmax(0, 1.1fr);
    gap: 26px;
    align-items: baseline;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ba-ring-seg,
  .page-about .ba-node,
  .page-about .ba-legend-item,
  .page-about .ba-tab {
    transition: none;
  }

  .page-about .ba-node:hover,
  .page-about .ba-node:focus-within {
    transform: none;
  }
}