.page-about {
  --ab-panel: rgba(14, 42, 37, 0.78);
  --ab-dim: #7E938C;
  --ab-radius: 2px;
  display: block;
  color: var(--text);
  background: var(--ink-900);
  overflow-x: clip;
}

.page-about p {
  margin: 0 0 1.1em;
  line-height: 1.85;
  font-size: 1rem;
}

.page-about p:last-child {
  margin-bottom: 0;
}

.page-about h1 {
  font-family: var(--font-title);
  font-weight: 800;
  font-size: clamp(2rem, 4.6vw, 3.4rem);
  line-height: 1.16;
  letter-spacing: -0.015em;
  margin: 0 0 0.6em;
  color: var(--text);
}

.page-about h2 {
  font-family: var(--font-title);
  font-weight: 800;
  font-size: clamp(1.35rem, 2.4vw, 2.1rem);
  line-height: 1.28;
  letter-spacing: -0.01em;
  margin: 0 0 0.6em;
  color: var(--text);
}

.page-about a {
  color: var(--cyan);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold-hi);
  margin: 0 0 14px;
}

.page-about .section-head {
  max-width: 64ch;
  margin-bottom: clamp(24px, 3.4vw, 40px);
}

.page-about .section-head > p:last-child {
  color: var(--muted);
  font-size: 0.98rem;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  padding-top: calc(var(--header-h) + 20px);
}

.page-about .breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .breadcrumbs li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

.page-about .breadcrumbs a {
  color: var(--muted);
  text-decoration: none;
}

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

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

/* ---------- 开篇分屏 ---------- */
.page-about .about-intro {
  padding-block: clamp(30px, 4vw, 52px) clamp(46px, 6vw, 84px);
}

.page-about .about-intro__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 52px);
}

.page-about .about-intro__lede {
  font-size: clamp(1.06rem, 1.4vw, 1.2rem);
  line-height: 1.8;
  color: var(--text);
  padding-left: 18px;
  border-left: 2px solid var(--gold);
  margin-bottom: 1.4em;
}

.page-about .about-intro__narrative p + p {
  color: var(--muted);
  font-size: 0.98rem;
}

@media (min-width: 920px) {
  .page-about .about-intro__grid {
    grid-template-columns: minmax(0, 1.32fr) minmax(0, 1fr);
    align-items: start;
  }
}

/* 边界卡 */
.page-about .about-boundary {
  position: relative;
  padding: clamp(22px, 3vw, 34px);
  border: 1px solid var(--line);
  border-radius: var(--ab-radius);
  background: linear-gradient(165deg, var(--ink-800) 0%, var(--ink-900) 78%);
}

.page-about .about-boundary::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 30%;
  height: 2px;
  background: linear-gradient(90deg, var(--gold) 0%, rgba(201, 162, 39, 0) 100%);
}

.page-about .about-boundary__title {
  font-size: clamp(1.1rem, 1.6vw, 1.32rem);
  margin: 0 0 0.55em;
}

.page-about .about-boundary__note {
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 1.5em;
}

.page-about .boundary-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .boundary-list li {
  position: relative;
  padding-left: 22px;
  font-size: 0.94rem;
  line-height: 1.7;
  color: var(--ab-dim);
  text-decoration: line-through;
  text-decoration-color: rgba(255, 122, 89, 0.5);
  text-decoration-thickness: 1px;
}

.page-about .boundary-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 9px;
  height: 9px;
  border: 1px solid var(--coral);
  transform: rotate(45deg);
}

.page-about .about-boundary__figure {
  margin: clamp(20px, 3vw, 28px) 0 0;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius);
  overflow: hidden;
  background: var(--ink-900);
}

.page-about .about-boundary__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  filter: saturate(0.86) brightness(0.9);
}

/* ---------- 口径概览条 ---------- */
.page-about .about-metrics {
  border-block: 1px solid var(--line);
  background: var(--ink-800);
}

.page-about .metric-row {
  list-style: none;
  margin: 0;
  padding: clamp(20px, 3vw, 30px) 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(18px, 2.5vw, 30px);
}

.page-about .metric-row .stat {
  display: grid;
  gap: 6px;
  padding-left: 14px;
  border-left: 1px solid var(--line-soft);
}

.page-about .metric-row .stat__label {
  font-size: 12px;
  line-height: 1.5;
  color: var(--muted);
  letter-spacing: 0.04em;
}

.page-about .metric-row .stat__value {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 2.8vw, 2.05rem);
  line-height: 1.1;
  color: var(--gold-hi);
  font-variant-numeric: tabular-nums;
}

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

/* ---------- 四步流程带 ---------- */
.page-about .about-flow {
  position: relative;
  border-block: 1px solid var(--line);
  background: var(--ink-800);
  overflow: hidden;
}

.page-about .about-flow__texture {
  position: absolute;
  inset: 0;
  z-index: 0;
  opacity: 0.16;
  pointer-events: none;
}

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

.page-about .about-flow__inner {
  position: relative;
  z-index: 1;
  padding-block: clamp(46px, 6.5vw, 88px);
}

.page-about .flow-rail {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

@media (min-width: 880px) {
  .page-about .flow-rail {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0;
  }
  .page-about .flow-rail > li {
    padding-inline: clamp(14px, 1.8vw, 26px);
    border-left: 1px solid var(--line-soft);
  }
  .page-about .flow-rail > li:first-child {
    border-left: 0;
    padding-left: 0;
  }
  .page-about .flow-rail > li:last-child {
    padding-right: 0;
  }
}

.page-about .flow-step {
  height: 100%;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius);
  background: rgba(7, 26, 23, 0.72);
  transition: border-color 220ms var(--ease), background-color 220ms var(--ease);
}

.page-about .flow-step:hover {
  border-color: var(--gold);
}

.page-about .flow-step[open] {
  border-color: var(--cyan);
  background: rgba(7, 26, 23, 0.92);
}

.page-about .flow-step__summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: clamp(16px, 2.2vw, 22px);
  cursor: pointer;
  list-style: none;
}

.page-about .flow-step__summary::-webkit-details-marker {
  display: none;
}

.page-about .flow-step__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--muted);
}

.page-about .flow-step[open] .flow-step__summary::after {
  content: "–";
  color: var(--cyan);
}

.page-about .flow-step__index {
  flex: none;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--gold-hi);
  border: 1px solid var(--gold);
  border-radius: 50%;
}

.page-about .flow-step[open] .flow-step__index {
  color: var(--ink-900);
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .flow-step__name {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
}

.page-about .flow-step__body {
  padding: 0 clamp(16px, 2.2vw, 22px) clamp(16px, 2.2vw, 22px);
  border-top: 1px dashed var(--line-soft);
  margin-top: 2px;
  padding-top: 16px;
}

.page-about .flow-step__body p {
  font-size: 0.92rem;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .flow-step__output {
  font-family: var(--font-mono);
  font-size: 12px !important;
  letter-spacing: 0.04em;
  color: var(--gold-hi) !important;
  padding-top: 10px;
  border-top: 1px solid var(--line-soft);
}

/* ---------- 版本演进 ---------- */
.page-about .about-evolution {
  padding-block: clamp(46px, 6.5vw, 92px);
}

.page-about .about-evolution__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(32px, 4.5vw, 64px);
}

@media (min-width: 980px) {
  .page-about .about-evolution__grid {
    grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
    align-items: start;
  }
}

.page-about .about-evolution__figure {
  margin: clamp(24px, 3vw, 34px) 0 0;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius);
  overflow: hidden;
  background: var(--ink-800);
}

.page-about .about-evolution__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  filter: saturate(0.8) brightness(0.86);
}

.page-about .about-evolution__figure .figure__caption {
  display: block;
  padding: 12px 16px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
  border-top: 1px solid var(--line-soft);
}

.page-about .era-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--gold);
}

.page-about .era {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  padding-block: clamp(20px, 2.6vw, 30px);
  border-bottom: 1px solid var(--line-soft);
}

@media (min-width: 720px) {
  .page-about .era {
    grid-template-columns: minmax(140px, 200px) minmax(0, 1fr);
    gap: clamp(20px, 3vw, 44px);
    align-items: start;
  }
}

.page-about .era__year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.2rem, 1.9vw, 1.55rem);
  letter-spacing: 0.02em;
  color: var(--gold-hi);
  padding-top: 2px;
}

.page-about .era__body p {
  margin: 0;
  font-size: 0.97rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .era:hover .era__year {
  color: var(--cyan);
}

/* ---------- 团队分工 ---------- */
.page-about .about-team {
  padding-block: clamp(46px, 6vw, 84px);
  background: var(--ink-800);
  border-block: 1px solid var(--line);
}

.page-about .table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border: 1px solid var(--line);
  border-radius: var(--ab-radius);
  background: var(--ink-900);
}

.page-about .team-table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
  font-size: 0.94rem;
}

.page-about .team-table__caption {
  caption-side: top;
  text-align: left;
  padding: 14px 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .team-table th,
.page-about .team-table td {
  padding: 15px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .team-table thead th {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold-hi);
  border-bottom: 1px solid var(--gold);
  white-space: nowrap;
}

.page-about .team-table tbody th {
  font-weight: 600;
  color: var(--text);
  white-space: nowrap;
}

.page-about .team-table tbody td {
  color: var(--muted);
  line-height: 1.7;
}

.page-about .team-table tbody tr:hover td,
.page-about .team-table tbody tr:hover th {
  background: rgba(20, 54, 48, 0.55);
}

.page-about .team-table .num {
  text-align: right;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--gold-hi);
  white-space: nowrap;
}

@media (max-width: 760px) {
  .page-about .team-table th:first-child {
    position: sticky;
    left: 0;
    z-index: 2;
    background: var(--ink-800);
    box-shadow: 1px 0 0 var(--line);
  }
  .page-about .team-table thead th:first-child {
    background: var(--ink-900);
  }
}

/* ---------- 内容准则 ---------- */
.page-about .about-rules {
  padding-block: clamp(46px, 6vw, 84px);
}

.page-about .about-rules__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 48px);
}

@media (min-width: 980px) {
  .page-about .about-rules__grid {
    grid-template-columns: minmax(240px, 0.72fr) minmax(0, 1.28fr);
    gap: clamp(32px, 5vw, 76px);
    align-items: start;
  }
  .page-about .about-rules .section-head {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    margin-bottom: 0;
  }
}

.page-about .rule-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
  border-radius: var(--ab-radius);
  overflow: hidden;
}

.page-about .rule-list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--ink-800);
}

.page-about .rule-list li:hover {
  background: var(--ink-700);
}

.page-about .rule-list__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold-hi);
  padding-top: 5px;
}

.page-about .rule-list p {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .rule-list strong {
  display: block;
  margin-bottom: 0.4em;
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--text);
}

/* ---------- 页面分工索引 ---------- */
.page-about .about-map {
  padding-block: clamp(46px, 6vw, 88px);
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, var(--ink-900) 0%, var(--ink-800) 100%);
}

.page-about .route-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

@media (min-width: 740px) {
  .page-about .route-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .route-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .route-list a {
  display: grid;
  align-content: start;
  gap: 8px;
  height: 100%;
  padding: clamp(18px, 2.2vw, 26px);
  border: 1px solid var(--line);
  border-radius: var(--ab-radius);
  background: rgba(7, 26, 23, 0.6);
  text-decoration: none;
  color: inherit;
  transition: border-color 220ms var(--ease), transform 220ms var(--ease);
}

.page-about .route-list a:hover {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .route-list__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .route-list__t {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
}

.page-about .route-list__d {
  font-size: 0.91rem;
  line-height: 1.72;
  color: var(--muted);
}

@media (prefers-reduced-motion: reduce) {
  .page-about .flow-step,
  .page-about .route-list a {
    transition: none;
  }
  .page-about .route-list a:hover {
    transform: none;
  }
}