.page-about {
  --about-axis: 34px;
  position: relative;
  color: var(--mist);
  padding-bottom: clamp(48px, 8vw, 96px);
  background-image:
    linear-gradient(rgba(159, 176, 184, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(159, 176, 184, 0.04) 1px, transparent 1px);
  background-size: 46px 46px, 46px 46px;
}

.page-about img {
  max-width: 100%;
}

.page-about .breadcrumbs {
  margin-top: clamp(14px, 2.4vw, 26px);
  margin-bottom: clamp(14px, 2.4vw, 26px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  display: grid;
  gap: clamp(20px, 3vw, 30px);
  padding: clamp(22px, 3.4vw, 42px);
  padding-left: clamp(26px, 3.8vw, 48px);
  border: var(--edge) solid var(--line-strong);
  background: var(--panel);
  box-shadow: var(--shadow-hard);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 6px;
  background: linear-gradient(180deg, var(--signal), rgba(53, 214, 255, 0.7));
}

.page-about .about-hero h1 {
  margin: 0;
  font-size: clamp(1.75rem, 5.4vw, 3.2rem);
  line-height: 1.2;
  letter-spacing: -0.015em;
  font-weight: 800;
  text-wrap: balance;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 48ch;
  font-size: clamp(0.96rem, 1.5vw, 1.06rem);
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-hero__stats {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 32px;
  margin: 0;
  padding: 16px 0 0;
  list-style: none;
  border-top: var(--edge) solid var(--line);
}

.page-about .stat {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.page-about .stat__num {
  font-family: var(--font-mono);
  font-size: clamp(1.35rem, 3vw, 1.85rem);
  font-weight: 700;
  line-height: 1;
  color: var(--signal);
  transform: skewX(-6deg);
  transform-origin: left bottom;
}

.page-about .stat__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.09em;
  color: var(--silver);
}

.page-about .about-hero__media {
  margin: 0;
  border: var(--edge) solid var(--line);
}

/* ---------- 章节索引 ---------- */
.page-about .manual-index {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 16px;
  margin: clamp(18px, 3vw, 30px) 0;
  padding: 12px 16px;
  border: var(--edge) solid var(--line);
  background: var(--deck);
}

.page-about .manual-index__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--muted);
}

.page-about .manual-index__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .manual-index__list a {
  display: inline-block;
  padding: 5px 13px;
  border: 1px solid var(--line-strong);
  color: var(--mist);
  font-size: 0.84rem;
  text-decoration: none;
  transition: border-color 160ms var(--ease), color 160ms var(--ease), transform 160ms var(--ease);
}

.page-about .manual-index__list a:hover,
.page-about .manual-index__list a:focus-visible {
  border-color: var(--signal);
  color: var(--signal);
  transform: translateX(2px);
}

/* ---------- 章节面板 ---------- */
.page-about .sec {
  position: relative;
  margin-bottom: clamp(20px, 3.4vw, 36px);
  padding: clamp(20px, 3.4vw, 40px);
  border: var(--edge) solid var(--line-strong);
  background: var(--panel);
  box-shadow: var(--shadow-hard);
  scroll-margin-top: 96px;
}

.page-about .sec--catalog {
  background: var(--deck);
}

.page-about .sec--cadence {
  background:
    linear-gradient(135deg, rgba(0, 229, 168, 0.07), transparent 46%),
    var(--panel);
}

.page-about .sec-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 16px;
  align-items: start;
  margin-bottom: clamp(16px, 2.6vw, 26px);
  padding-bottom: 14px;
  border-bottom: var(--edge) solid var(--line);
}

.page-about .sec-num {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3.4vw, 2.3rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: rgba(0, 229, 168, 0.42);
  -webkit-text-stroke: 1px var(--signal);
}

.page-about .sec-head h2 {
  margin: 0;
  font-size: clamp(1.3rem, 3.2vw, 2rem);
  line-height: 1.26;
  letter-spacing: -0.012em;
  font-weight: 800;
}

.page-about .sec-head__sub {
  grid-column: 2;
  margin: 4px 0 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--flare);
}

.page-about .sec p {
  line-height: 1.75;
  color: var(--silver);
  max-width: 68ch;
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  position: relative;
  margin: 0;
  padding: 6px 0 6px var(--about-axis);
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 10px;
  bottom: 10px;
  width: var(--edge);
  background: linear-gradient(180deg, var(--signal) 0%, rgba(0, 229, 168, 0.16) 62%, rgba(53, 214, 255, 0.55) 100%);
}

.page-about .tl-node {
  position: relative;
  padding-bottom: clamp(18px, 3vw, 28px);
}

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

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: -31px;
  top: 5px;
  width: 12px;
  height: 12px;
  background: var(--ink);
  border: var(--edge) solid var(--signal);
}

.page-about .tl-node--now::before {
  background: var(--flare);
  border-color: var(--flare);
  box-shadow: 0 0 0 4px rgba(255, 90, 46, 0.16);
}

.page-about .tl-node__year {
  display: inline-block;
  margin-bottom: 8px;
  padding: 2px 9px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--flare);
  background: rgba(255, 90, 46, 0.09);
  border: 1px solid rgba(255, 90, 46, 0.42);
}

.page-about .tl-node h3 {
  margin: 0 0 6px;
  font-size: clamp(1rem, 2.1vw, 1.18rem);
  line-height: 1.4;
  color: var(--mist);
}

.page-about .tl-node p {
  margin: 0;
  max-width: 62ch;
  line-height: 1.72;
  color: var(--silver);
}

/* ---------- 两条主线 ---------- */
.page-about .catalog-grid {
  display: grid;
  gap: clamp(14px, 2.4vw, 22px);
}

.page-about .catalog-card {
  padding: clamp(16px, 2.6vw, 26px);
  border: var(--edge) solid var(--line-strong);
  background: var(--panel);
  box-shadow: var(--shadow-hard);
  transition: transform 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .catalog-card:hover {
  transform: translate(-2px, -2px);
  border-color: var(--signal);
}

.page-about .catalog-card h3 {
  margin: 0 0 10px;
  font-size: clamp(1.04rem, 2vw, 1.28rem);
  color: var(--mist);
}

.page-about .catalog-card p {
  margin: 0 0 14px;
  max-width: none;
  line-height: 1.72;
  color: var(--silver);
}

.page-about .catalog-card__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 14px 0 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .catalog-card__list li {
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  border: 1px solid rgba(53, 214, 255, 0.4);
}

.page-about .sport-strip {
  margin-top: clamp(18px, 3vw, 28px);
  padding-top: clamp(16px, 2.6vw, 24px);
  border-top: var(--edge) solid var(--line);
}

.page-about .sport-strip__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .sport-strip__list .tag {
  font-size: 12px;
  padding: 4px 12px;
}

/* ---------- 图文错位 ---------- */
.page-about .split {
  display: grid;
  gap: clamp(18px, 3vw, 32px);
}

.page-about .split__media {
  margin: 0;
  border: var(--edge) solid var(--line);
}

.page-about .split__body p {
  margin: 0 0 14px;
  line-height: 1.75;
  color: var(--silver);
}

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

.page-about .split__body .sec-head {
  margin-bottom: clamp(14px, 2.4vw, 20px);
}

/* ---------- 版本区 ---------- */
.page-about .version-area {
  margin-top: clamp(18px, 3vw, 28px);
  padding-top: clamp(16px, 2.6vw, 24px);
  border-top: var(--edge) solid var(--line);
}

.page-about .version-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 11px 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--ink);
  background: var(--signal);
  border: var(--edge) solid var(--signal);
  box-shadow: var(--shadow-hard);
  cursor: pointer;
  transition: transform 160ms var(--ease), background 160ms var(--ease);
}

.page-about .version-btn:hover,
.page-about .version-btn:focus-visible {
  transform: translate(-2px, -2px);
  background: var(--mist);
  border-color: var(--mist);
}

.page-about .version-btn__dot {
  width: 8px;
  height: 8px;
  background: var(--flare);
  animation: about-pulse 1.8s var(--ease) infinite;
}

@keyframes about-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

.page-about .version-panel {
  margin-top: 16px;
  padding: clamp(16px, 2.4vw, 24px);
  border: var(--edge) solid rgba(0, 229, 168, 0.4);
  background: var(--deck);
  box-shadow: var(--shadow-signal);
}

.page-about .version-panel h3 {
  margin: 0 0 12px;
  font-size: 1.05rem;
  color: var(--signal);
}

.page-about .version-panel ul {
  margin: 0 0 12px;
  padding-left: 20px;
}

.page-about .version-panel li {
  margin-bottom: 8px;
  line-height: 1.7;
  color: var(--silver);
}

.page-about .version-panel__meta,
.page-about .version-panel .stamp {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

/* ---------- 收尾 ---------- */
.page-about .cta-deck {
  position: relative;
  margin-top: clamp(20px, 3.4vw, 36px);
  padding: clamp(22px, 3.4vw, 40px);
  border: var(--edge) solid var(--line-strong);
  background:
    linear-gradient(120deg, rgba(53, 214, 255, 0.08), transparent 55%),
    var(--deck);
  box-shadow: var(--shadow-hard);
}

.page-about .cta-deck h2 {
  margin: 0 0 12px;
  font-size: clamp(1.3rem, 3vw, 1.9rem);
  line-height: 1.26;
  color: var(--mist);
}

.page-about .cta-deck p {
  margin: 0 0 20px;
  max-width: 62ch;
  line-height: 1.75;
  color: var(--silver);
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .catalog-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .sec-head {
    grid-template-columns: auto minmax(0, 1fr) auto;
    align-items: center;
  }

  .page-about .sec-head__sub {
    grid-column: 3;
    margin: 0;
    writing-mode: vertical-rl;
    text-orientation: mixed;
    justify-self: end;
    align-self: start;
    padding-left: 8px;
    border-left: 1px solid rgba(255, 90, 46, 0.35);
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: start;
    column-gap: clamp(28px, 4vw, 54px);
  }

  .page-about .about-hero > * {
    grid-column: 1;
  }

  .page-about .about-hero > .about-hero__media {
    grid-column: 2;
    grid-row: 1 / span 4;
    align-self: start;
  }

  .page-about .split--a {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    align-items: start;
  }

  .page-about .split--b {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: start;
  }

  .page-about .split__body .sec-head {
    border-bottom-color: var(--line-strong);
  }
}

@media (min-width: 1080px) {
  .page-about .timeline {
    padding-left: 46px;
  }

  .page-about .tl-node::before {
    left: -43px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}