.page-about {
  --about-measure: 36em;
  --about-side-w: 17rem;
  overflow-x: clip;
}

.page-about .breadcrumb {
  padding-block: 1.5rem 0.25rem;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-block: clamp(1.5rem, 4vw, 2.5rem) clamp(2.5rem, 6vw, 4.5rem);
  border-bottom: 2px solid var(--line);
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.15rem, 6.6vw, 4.4rem);
  font-weight: 800;
  line-height: 1.02;
  letter-spacing: -0.035em;
  color: var(--text);
  margin: 0.65rem 0 1.35rem;
  max-width: 19ch;
  text-wrap: balance;
}

.page-about .about-lead {
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--muted);
  max-width: var(--about-measure);
  margin: 0 0 2.25rem;
}

.page-about .hero-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 1px;
  background: var(--line);
  border: 2px solid var(--line);
}

.page-about .hero-facts > div {
  background: var(--ink);
  padding: 0.85rem 1rem 0.95rem;
}

.page-about .hero-facts dt {
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.4rem;
}

.page-about .hero-facts dd {
  margin: 0;
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 1.3rem;
  letter-spacing: 0.01em;
  color: var(--text);
  white-space: nowrap;
}

.page-about .hero-facts > div:first-child dd {
  color: var(--amber);
}

/* ---------- 通用章节 ---------- */
.page-about .about-section {
  padding-block: clamp(2.75rem, 6vw, 5rem);
}

.page-about .sec-index {
  display: inline-block;
  font-family: var(--font-data);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--ink);
  background: var(--amber);
  padding: 0.18rem 0.55rem;
  margin-bottom: 0.85rem;
}

.page-about .section-head h2 {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3.6vw, 2.5rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.025em;
  color: var(--text);
  margin: 0 0 0.85rem;
  max-width: 22ch;
}

.page-about .section-sub {
  font-size: 1rem;
  line-height: 1.78;
  color: var(--muted);
  max-width: var(--about-measure);
  margin: 0;
}

.page-about .about-body {
  max-width: var(--about-measure);
}

.page-about .about-body p {
  margin: 0 0 1.35rem;
  color: var(--text);
}

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

/* :target 联动高亮 */
.page-about .about-body p:target {
  border-left: 3px solid var(--amber);
  padding-left: 1rem;
  margin-left: -1rem;
  background: rgba(242, 178, 60, 0.07);
}

/* ---------- 双栏：正文 + 边注 ---------- */
.page-about .about-cols {
  display: grid;
  gap: clamp(1.75rem, 4vw, 3rem);
  margin-top: 2rem;
}

.page-about .about-side {
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--muted);
  border-top: 2px solid var(--line);
  padding-top: 1.25rem;
}

.page-about .about-side .media {
  margin: 0 0 1.25rem;
}

.page-about .side-note {
  margin: 0 0 0.9rem;
  padding-left: 0.8rem;
  border-left: 2px solid var(--line-2);
}

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

.page-about .side-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 160ms var(--ease);
}

.page-about .side-note a:hover,
.page-about .side-note a:focus-visible {
  border-bottom-color: var(--cyan);
}

.page-about .media-caption {
  font-size: 0.75rem;
  line-height: 1.6;
  color: var(--muted);
  padding-top: 0.6rem;
}

/* ---------- 三层结构带 ---------- */
.page-about .about-band {
  padding-block: clamp(2.75rem, 6vw, 4.75rem);
}

.page-about .stack-diagram {
  list-style: none;
  margin: 2.25rem 0 0;
  padding: 0;
  display: grid;
  gap: 2.5rem;
}

.page-about .stack-node {
  position: relative;
  background: var(--panel);
  border: 2px solid var(--line);
  box-shadow: var(--shadow-sm);
  padding: 1.25rem 1.25rem 1.45rem;
  transition: border-color 200ms var(--ease), box-shadow 200ms var(--ease);
}

.page-about .stack-node:hover {
  border-color: var(--line-2);
  box-shadow: var(--shadow);
}

.page-about .stack-node:nth-child(2) {
  width: 94%;
  margin-left: 6%;
}

.page-about .stack-node:nth-child(3) {
  width: 88%;
  margin-left: 12%;
}

.page-about .stack-node:not(:last-child)::after {
  content: "";
  position: absolute;
  left: 1.9rem;
  bottom: -1.9rem;
  width: 2.6rem;
  height: 2px;
  background: linear-gradient(90deg, var(--amber), rgba(242, 178, 60, 0));
  transform: rotate(54deg);
  transform-origin: left center;
  pointer-events: none;
}

.page-about .stack-num {
  display: block;
  font-family: var(--font-data);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--amber);
  margin-bottom: 0.55rem;
}

.page-about .stack-node h3 {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.015em;
  color: var(--text);
  margin: 0 0 0.6rem;
}

.page-about .stack-node p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--muted);
  max-width: 40em;
}

/* ---------- 赛季时间轴 ---------- */
.page-about .era-track {
  list-style: none;
  margin: 2.25rem 0 0;
  padding: 0;
  position: relative;
}

.page-about .era-track::before {
  content: "";
  position: absolute;
  left: 0.1875rem;
  top: 1.5rem;
  bottom: 1.5rem;
  width: 2px;
  background: linear-gradient(180deg, var(--amber) 0%, var(--line-2) 62%, rgba(27, 64, 56, 0.2) 100%);
}

.page-about .era {
  position: relative;
  padding-left: 2rem;
  padding-bottom: 0.9rem;
}

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

.page-about .era::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.42rem;
  width: 0.9rem;
  height: 3px;
  background: var(--amber);
  pointer-events: none;
}

.page-about .era-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 0.9rem;
  width: 100%;
  text-align: left;
  background: var(--panel);
  border: 2px solid var(--line);
  color: inherit;
  font: inherit;
  padding: 0.85rem 1rem;
  cursor: pointer;
  transition: border-color 180ms var(--ease), transform 180ms var(--ease);
}

.page-about .era-head:hover {
  border-color: var(--line-2);
}

.page-about .era-head:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .era-head[aria-expanded="true"] {
  border-color: var(--cyan);
}

.page-about .era-year {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 1.2rem;
  letter-spacing: 0.02em;
  color: var(--amber);
}

.page-about .era-title {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0;
  color: var(--text);
  overflow-wrap: anywhere;
}

.page-about .era-hint {
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--muted);
  border: 1px solid var(--line);
  padding: 0.15rem 0.45rem;
  white-space: nowrap;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .era-head[aria-expanded="true"] .era-hint {
  color: var(--cyan);
  border-color: var(--cyan);
}

.page-about .era .disclosure-panel[data-open="true"] {
  margin-top: 0;
}

.page-about .era-panel-inner {
  border: 2px solid var(--line);
  border-top: 0;
  background: var(--ink-2);
  padding: 0.95rem 1rem 1.15rem;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .era-panel-inner p {
  margin: 0;
  max-width: 40em;
}

/* ---------- 分工章节 ---------- */
.page-about .duty-list {
  list-style: none;
  margin: 1.5rem 0;
  padding: 0;
  border-top: 2px solid var(--line);
}

.page-about .duty-list li {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 0.3rem 1rem;
  padding: 0.9rem 0;
  border-bottom: 1px solid var(--line);
}

.page-about .duty-role {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
}

.page-about .duty-count {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 0.875rem;
  color: var(--amber);
  white-space: nowrap;
  align-self: center;
}

.page-about .duty-desc {
  grid-column: 1 / -1;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .cadence {
  display: grid;
  gap: 1px;
  padding: 1px;
  background: var(--line);
  border: 2px solid var(--line);
  margin: 1.75rem 0 0;
}

.page-about .cadence-step {
  background: var(--panel);
  padding: 0.85rem 1rem;
  display: grid;
  gap: 0.3rem;
}

.page-about .cadence-time {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 1.15rem;
  letter-spacing: 0.02em;
  color: var(--amber);
  white-space: nowrap;
}

.page-about .cadence-label {
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .about-cols--flip .media {
  margin: 0;
}

/* ---------- 内容边界 ---------- */
.page-about .rule-list {
  list-style: none;
  padding: 0;
  margin: 1.5rem 0;
  display: grid;
  gap: 0.9rem;
}

.page-about .rule-list li {
  position: relative;
  padding-left: 1.65rem;
  font-size: 1rem;
  line-height: 1.78;
  color: var(--text);
}

.page-about .rule-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.78em;
  width: 0.9rem;
  height: 2px;
  background: var(--cyan);
}

.page-about .contact-inline {
  font-family: var(--font-data);
  font-size: 0.9375rem;
  color: var(--cyan);
  overflow-wrap: anywhere;
}

/* ---------- 页末尾带 ---------- */
.page-about .about-outro {
  padding-block: clamp(2.5rem, 6vw, 4.5rem);
}

.page-about .about-outro-media {
  display: block;
  margin: 0;
  aspect-ratio: 8 / 3;
  overflow: hidden;
  border: 2px solid var(--line);
  background: var(--ink);
}

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

.page-about .about-outro-body {
  padding-top: 1.75rem;
  max-width: 46em;
}

.page-about .about-outro-body p {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text);
  margin: 0 0 1rem;
}

.page-about .about-outro-note {
  color: var(--muted);
  font-size: 0.9375rem;
}

.page-about .outro-links {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  padding: 0;
  margin: 1.5rem 0 0;
}

.page-about .outro-links a {
  display: inline-block;
  padding: 0.45rem 0.9rem;
  border: 2px solid var(--line);
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: var(--text);
  text-decoration: none;
  transition: border-color 160ms var(--ease), color 160ms var(--ease), background-color 160ms var(--ease);
}

.page-about .outro-links a:hover,
.page-about .outro-links a:focus-visible {
  border-color: var(--cyan);
  color: var(--cyan);
  background: rgba(62, 242, 206, 0.06);
}

/* ---------- 响应式 ---------- */
@media (min-width: 40rem) {
  .page-about .hero-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 58rem) {
  .page-about .about-cols {
    grid-template-columns: minmax(0, 1fr) var(--about-side-w);
  }

  .page-about .about-cols--flip {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1.25fr);
    align-items: start;
  }

  .page-about .about-side {
    border-top: 0;
    border-left: 2px solid var(--line);
    padding-top: 0;
    padding-left: 1.4rem;
  }

  .page-about .about-cols--flip .media {
    position: sticky;
    top: 2rem;
  }

  .page-about .stack-diagram {
    margin-top: 2.75rem;
  }

  .page-about .era {
    padding-bottom: 1.1rem;
  }

  .page-about .era-title {
    font-size: 1.15rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stack-node,
  .page-about .era-head,
  .page-about .outro-links a,
  .page-about .side-note a {
    transition: none;
  }
}