.page-about {
  --about-axis: 1px solid var(--g700);
  --about-cut: polygon(12px 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%, 0 12px);
}

/* ---------- 面包屑行 ---------- */
.page-about .about-crumb-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding-top: clamp(1rem, 3vw, 1.75rem);
}

.page-about .about-crumb-note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--mist);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(1.5rem, 4vw, 3rem);
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(1.75rem, 5vw, 3rem);
  align-items: end;
}

.page-about h1 {
  margin: 0.4rem 0 1.1rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.2rem, 8vw, 4.4rem);
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .about-lede {
  margin: 0 0 1rem;
  font-size: clamp(1rem, 2.4vw, 1.12rem);
  line-height: 1.8;
  color: var(--text-dim);
  max-width: 62ch;
}

.page-about .about-lede-sub {
  margin: 0 0 1.4rem;
  padding-left: 1rem;
  border-left: 2px solid var(--g700);
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--mist);
  max-width: 58ch;
}

.page-about .about-hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.page-about .about-hero-media {
  margin: 0;
}

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

/* ---------- 板块标题通用 ---------- */
.page-about .about-sec-head {
  max-width: 68ch;
  margin-bottom: clamp(1.75rem, 4vw, 2.75rem);
}

/* ---------- 赛季时间轴 ---------- */
.page-about .year-rail {
  display: flex;
  gap: 0.4rem;
  overflow-x: auto;
  padding-bottom: 0.75rem;
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.page-about .year-rail a {
  flex: 0 0 auto;
  padding: 0.42rem 0.85rem;
  border: 1px solid var(--g700);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  color: var(--text-dim);
  text-decoration: none;
  clip-path: polygon(9px 0, 100% 0, 100% calc(100% - 9px), calc(100% - 9px) 100%, 0 100%, 0 9px);
  transition: background 180ms ease, color 180ms ease, border-color 180ms ease;
}

.page-about .year-rail a:hover,
.page-about .year-rail a:focus-visible {
  background: var(--lime);
  border-color: var(--lime);
  color: var(--ink);
  outline: none;
}

.page-about .tl-wrap {
  border-left: var(--about-axis);
  padding-left: clamp(1rem, 3.5vw, 2rem);
}

.page-about .tl-node {
  position: relative;
  display: grid;
  gap: 0.85rem;
  padding: 0 0 clamp(2rem, 5vw, 3.25rem);
}

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

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: calc(clamp(1rem, 3.5vw, 2rem) * -1 - 4.5px);
  top: 0.7rem;
  width: 8px;
  height: 8px;
  background: var(--lime);
  transform: rotate(45deg);
}

.page-about .tl-year {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.page-about .tl-year .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
  font-size: clamp(1.7rem, 6vw, 2.6rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--lime);
}

.page-about .tl-year-note {
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .tl-body h3 {
  margin: 0 0 0.5rem;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(1.1rem, 3vw, 1.4rem);
  line-height: 1.45;
  color: var(--white);
}

.page-about .tl-body p {
  margin: 0;
  font-size: 0.97rem;
  line-height: 1.8;
  color: var(--text-dim);
  max-width: 66ch;
}

.page-about .tl-node--current .tl-body {
  padding: 1.1rem 1.25rem;
  background: var(--g800);
  clip-path: var(--about-cut);
  border-left: 3px solid var(--lime);
}

/* ---------- 档案规模 ---------- */
.page-about .about-archive {
  padding-block: clamp(2.5rem, 7vw, 4.5rem);
}

.page-about .about-archive-grid {
  display: grid;
  gap: clamp(1.75rem, 5vw, 3rem);
}

.page-about .about-archive-link {
  margin: 1rem 0 0;
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--text-dim);
}

.page-about .about-archive-link a {
  color: var(--lime);
  text-underline-offset: 3px;
}

.page-about .about-archive-figures {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1px;
  background: var(--g700);
  border: 1px solid var(--g700);
}

.page-about .about-archive-figures .metric {
  background: var(--g900);
  padding: 1.1rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.page-about .about-archive-figures .metric-value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
  font-size: clamp(2rem, 7vw, 2.8rem);
  line-height: 1;
  color: var(--white);
}

.page-about .about-archive-figures .metric-label {
  font-size: 0.72rem;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .about-spark {
  grid-column: 1 / -1;
  margin: 0;
  background: var(--g900);
  padding: 1rem 1rem 0.75rem;
}

.page-about .spark-svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .spark-line {
  fill: none;
  stroke: var(--lime);
  stroke-width: 2;
  stroke-linejoin: round;
  stroke-linecap: round;
}

.page-about .spark-base {
  stroke: var(--g700);
  stroke-width: 1;
}

.page-about .spark-caption {
  margin-top: 0.5rem;
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--mist);
}

/* ---------- 联赛分组 ---------- */
.page-about .about-league-switch {
  margin-bottom: 0.75rem;
}

.page-about .group-grid {
  display: grid;
  gap: 1px;
  background: var(--g700);
  border: 1px solid var(--g700);
  margin-top: clamp(1.25rem, 3vw, 2rem);
}

.page-about .group-card {
  background: var(--g900);
  padding: clamp(1.1rem, 3vw, 1.5rem);
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.page-about .group-card h3 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.01em;
  color: var(--lime);
}

.page-about .group-card p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--text-dim);
}

.page-about .group-card .group-meta {
  margin-top: auto;
  padding-top: 0.6rem;
  border-top: 1px solid var(--g700);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--mist);
}

/* ---------- 复核链路 ---------- */
.page-about .about-wide-media {
  margin: 0 0 clamp(1.75rem, 4vw, 2.75rem);
}

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

.page-about .pipe-path {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .pipe-step {
  position: relative;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1rem;
  padding: 1.15rem 0 1.15rem 0;
  border-bottom: 1px dashed var(--g700);
}

.page-about .pipe-step:first-child {
  border-top: 1px dashed var(--g700);
}

.page-about .pipe-step::before {
  content: "";
  position: absolute;
  left: 1.35rem;
  top: 0;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, var(--lime) 0%, var(--g700) 100%);
  opacity: 0.5;
}

.page-about .pipe-step:last-child::before {
  bottom: 50%;
}

.page-about .pipe-index {
  position: relative;
  z-index: 1;
  align-self: start;
  width: 2.7rem;
  height: 2.7rem;
  display: grid;
  place-items: center;
  background: var(--g800);
  color: var(--lime);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.9rem;
  font-weight: 500;
  clip-path: polygon(9px 0, 100% 0, 100% calc(100% - 9px), calc(100% - 9px) 100%, 0 100%, 0 9px);
  border: 1px solid var(--g700);
}

.page-about .pipe-content h3 {
  margin: 0 0 0.4rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.12rem;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .pipe-content p {
  margin: 0 0 0.55rem;
  font-size: 0.94rem;
  line-height: 1.78;
  color: var(--text-dim);
  max-width: 64ch;
}

.page-about .pipe-owner {
  display: inline-block;
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mist);
}

/* ---------- 公开修订 ---------- */
.page-about .about-revision {
  padding-block: clamp(2.5rem, 7vw, 4.5rem);
}

.page-about .about-revision-grid {
  display: grid;
  gap: clamp(1.75rem, 5vw, 3rem);
}

.page-about .about-revision-copy p {
  margin: 0 0 1rem;
  font-size: 0.97rem;
  line-height: 1.8;
  color: var(--text-dim);
  max-width: 64ch;
}

.page-about .about-revision-copy a {
  color: var(--lime);
  text-underline-offset: 3px;
}

.page-about .about-revision-spec {
  padding: clamp(1.1rem, 3vw, 1.6rem);
  background: var(--g800);
  clip-path: var(--about-cut);
  border-top: 3px solid var(--lime);
}

.page-about .about-revision-spec h3 {
  margin: 0 0 1rem;
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
  font-weight: 600;
}

.page-about .spec-list {
  margin: 0;
  display: grid;
  gap: 0.9rem;
}

.page-about .spec-row {
  display: grid;
  gap: 0.25rem;
  padding-bottom: 0.85rem;
  border-bottom: 1px solid var(--g700);
}

.page-about .spec-row:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.page-about .spec-row dt {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  color: var(--lime);
}

.page-about .spec-row dd {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--text-dim);
}

.page-about .spec-foot {
  margin: 1.1rem 0 0;
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--amber);
}

/* ---------- 工作节奏 ---------- */
.page-about .about-team-grid {
  display: grid;
  gap: clamp(1.75rem, 5vw, 3rem);
}

.page-about .about-team-media {
  margin: 0;
}

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

.page-about .about-team-copy p {
  margin: 0 0 1rem;
  font-size: 0.97rem;
  line-height: 1.8;
  color: var(--text-dim);
  max-width: 64ch;
}

.page-about .about-team-copy a {
  color: var(--lime);
  text-underline-offset: 3px;
}

.page-about .rhythm-list {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--g700);
  border: 1px solid var(--g700);
}

.page-about .rhythm-list li {
  background: var(--g900);
  display: grid;
  grid-template-columns: auto auto 1fr;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.9rem 1rem;
}

.page-about .rhythm-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
  font-size: 1.5rem;
  line-height: 1;
  color: var(--lime);
}

.page-about .rhythm-unit {
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .rhythm-text {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text-dim);
}

/* ---------- 边界说明 ---------- */
.page-about .boundary-panel {
  background: var(--g800);
  clip-path: var(--about-cut);
  border-left: 3px solid var(--alert);
}

.page-about .boundary-panel summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: clamp(1rem, 3vw, 1.4rem) clamp(1rem, 3vw, 1.6rem);
}

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

.page-about .boundary-panel summary:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: -3px;
}

.page-about .boundary-summary-text {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1rem, 3vw, 1.2rem);
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .boundary-toggle {
  font-family: var(--font-mono);
  font-size: 1.4rem;
  line-height: 1;
  color: var(--lime);
  transition: transform 200ms ease;
}

.page-about .boundary-panel[open] .boundary-toggle {
  transform: rotate(45deg);
}

.page-about .boundary-list {
  list-style: none;
  margin: 0;
  padding: 0 clamp(1rem, 3vw, 1.6rem) clamp(1rem, 3vw, 1.6rem);
  display: grid;
  gap: 1rem;
}

.page-about .boundary-list li {
  padding-top: 1rem;
  border-top: 1px solid var(--g700);
}

.page-about .boundary-list h3 {
  margin: 0 0 0.4rem;
  font-size: 1rem;
  line-height: 1.5;
  color: var(--white);
  font-weight: 600;
}

.page-about .boundary-list p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--text-dim);
  max-width: 70ch;
}

.page-about .about-close-band {
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
  padding-top: clamp(1.25rem, 3vw, 1.75rem);
  border-top: 1px solid var(--g700);
}

.page-about .about-close-text {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--text-dim);
  max-width: 74ch;
}

.page-about .about-close-text a {
  color: var(--lime);
  text-underline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .group-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about .rhythm-list li {
    grid-template-columns: 6rem 4rem 1fr;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: 7fr 4fr;
    gap: clamp(2rem, 4vw, 3.5rem);
  }

  .page-about .tl-node {
    grid-template-columns: 13rem 1fr;
    gap: clamp(1.5rem, 3vw, 2.5rem);
    align-items: start;
  }

  .page-about .tl-year {
    position: sticky;
    top: 7.5rem;
  }

  .page-about .about-archive-grid {
    grid-template-columns: 6fr 5fr;
    gap: clamp(2rem, 4vw, 3.5rem);
    align-items: start;
  }

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

  .page-about .about-revision-grid {
    grid-template-columns: 7fr 4fr;
    gap: clamp(2rem, 4vw, 3.5rem);
    align-items: start;
  }

  .page-about .about-team-grid {
    grid-template-columns: 4fr 7fr;
    gap: clamp(2rem, 4vw, 3.5rem);
    align-items: start;
  }

  .page-about .about-team-media {
    position: sticky;
    top: 7.5rem;
  }
}

@media (min-width: 1100px) {
  .page-about .about-hero-grid {
    grid-template-columns: 6fr 5fr;
  }

  .page-about .about-wide-media {
    margin-inline: -2rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .year-rail a,
  .page-about .boundary-toggle {
    transition: none;
  }
}