.page-about {
  --about-rail-w: 208px;
  --about-strip-bg: var(--c-paper-card);
  --about-strip-ink: var(--c-green);
}

.page-about a {
  color: inherit;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(28px, 4.6vw, 68px) clamp(26px, 3.4vw, 48px);
  border-bottom: 1px solid var(--wire-line);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(46%, 480px);
  background-image: repeating-linear-gradient(
    118deg,
    rgba(183, 255, 60, 0.06) 0 1px,
    transparent 1px 46px
  );
  pointer-events: none;
}

.page-about .about-hero > * {
  position: relative;
}

.page-about .about-hero h1 {
  margin: 12px 0 0;
  font-family: var(--f-display);
  font-size: var(--fs-h1);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: 0.01em;
  text-transform: uppercase;
  color: var(--c-paper);
}

.page-about .about-lede {
  max-width: 42em;
  margin: 18px 0 0;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: var(--c-steel);
}

.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: clamp(26px, 3.6vw, 44px) 0 0;
  padding: 0;
  border-top: 1px solid var(--wire-line);
  border-left: 1px solid var(--wire-line);
}

.page-about .about-figure {
  padding: 14px 16px 16px;
  border-right: 1px solid var(--wire-line);
  border-bottom: 1px solid var(--wire-line);
}

.page-about .about-figure dt {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--c-steel-mid);
}

.page-about .about-figure dd {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 6px 0 0;
  color: var(--c-lime);
}

.page-about .about-figure .num {
  color: var(--c-lime);
}

.page-about .about-unit {
  font-family: var(--f-body);
  font-size: 13px;
  color: var(--c-steel);
}

/* ---------- 布局骨架 ---------- */
.page-about .about-layout {
  display: block;
  padding-block: clamp(24px, 3vw, 40px) clamp(40px, 6vw, 96px);
}

/* ---------- 章节索引 ---------- */
.page-about .about-rail {
  padding: 0 0 18px;
  border-bottom: 1px solid var(--wire-line);
}

.page-about .about-rail-label {
  margin: 0 0 10px;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--c-steel-mid);
}

.page-about .about-rail-list {
  display: flex;
  gap: 4px;
  margin: 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail-list li {
  flex: 0 0 auto;
}

.page-about .about-rail-list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--wire-hair);
  font-size: 13px;
  color: var(--c-steel);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-rail-idx {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--c-lime-mid);
}

.page-about .about-rail-list a:hover,
.page-about .about-rail-list a:focus-visible {
  color: var(--c-paper);
  border-color: var(--lime-soft);
  background: var(--c-panel);
  transform: translateX(2px);
}

/* ---------- 正文 ---------- */
.page-about .about-chapter {
  padding-block: clamp(30px, 4.4vw, 58px);
  border-top: 1px solid var(--wire-hair);
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: clamp(8px, 1.4vw, 16px);
}

.page-about .about-chapter-idx {
  margin: 0 0 10px;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-lime);
}

.page-about .about-chapter h2 {
  margin: 0 0 16px;
  font-family: var(--f-display);
  font-size: var(--fs-h2);
  font-weight: 700;
  line-height: 1.14;
  letter-spacing: 0.01em;
  color: var(--c-paper);
}

.page-about .about-chapter h3 {
  margin: 0 0 12px;
  font-family: var(--f-display);
  font-size: var(--fs-h3);
  font-weight: 600;
  line-height: 1.25;
  color: var(--c-paper);
}

.page-about .about-chapter p.prose {
  max-width: 34em;
  margin: 0 0 16px;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: var(--c-steel);
}

.page-about .about-note {
  max-width: 32em;
  margin: 0;
  padding-left: 14px;
  border-left: 2px solid var(--c-orange);
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-steel);
}

/* ---------- 图片 ---------- */
.page-about .about-media {
  margin: clamp(20px, 2.8vw, 32px) 0;
}

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

/* ---------- 横向数据条 ---------- */
.page-about .about-strip {
  position: relative;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1px;
  margin: clamp(24px, 3.4vw, 40px) 0;
  padding: clamp(18px, 2.6vw, 28px);
  background: var(--about-strip-bg);
  color: var(--about-strip-ink);
  box-shadow: 6px 6px 0 0 rgba(216, 224, 220, 0.08);
}

.page-about .about-strip-item {
  padding: 4px 14px 4px 0;
  border-left: 1px solid rgba(14, 26, 23, 0.16);
  padding-left: 14px;
}

.page-about .about-strip-item:first-child {
  border-left: 0;
  padding-left: 0;
}

.page-about .about-strip-num {
  margin: 0;
  font-family: var(--f-mono);
  font-size: clamp(26px, 3.2vw, 42px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
  color: var(--about-strip-ink);
}

.page-about .about-strip-cap {
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.6;
  color: rgba(14, 26, 23, 0.72);
}

/* ---------- 校验章节 ---------- */
.page-about .about-pair {
  display: grid;
  gap: clamp(18px, 2.6vw, 32px);
  margin-top: clamp(20px, 2.8vw, 30px);
}

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

.page-about .about-check-list {
  margin: 0 0 18px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .about-check-list li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-steel);
}

.page-about .about-check-list .tag {
  flex: 0 0 auto;
  margin-top: 3px;
}

/* ---------- 时间轴 SVG ---------- */
.page-about .about-timeline {
  display: block;
  width: 100%;
  max-width: 720px;
  height: auto;
  margin: clamp(20px, 2.8vw, 30px) 0;
  overflow: visible;
}

.page-about .about-timeline rect {
  fill: rgba(183, 255, 60, 0.12);
  stroke: var(--c-lime-mid);
  stroke-width: 1;
}

.page-about .about-timeline .tl-extra {
  fill: rgba(255, 106, 43, 0.16);
  stroke: var(--c-orange);
  stroke-dasharray: 5 4;
}

.page-about .about-timeline text {
  font-family: var(--f-mono);
  font-size: 15px;
  letter-spacing: 0.03em;
  fill: var(--c-steel);
}

.page-about .about-timeline .tl-extra-label {
  fill: var(--c-orange);
}

.page-about .about-timeline .tl-axis {
  stroke: var(--wire-line);
  stroke-width: 1;
}

.page-about .about-timeline .tl-unit {
  font-size: 13px;
  fill: var(--c-steel-mid);
}

/* ---------- 版本列表 ---------- */
.page-about .about-version-list {
  margin-top: clamp(18px, 2.4vw, 26px);
}

.page-about .about-version-list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.page-about .about-version-name {
  font-size: 15px;
  color: var(--c-steel);
}

.page-about .about-version-tag {
  flex: 0 0 auto;
  color: var(--c-lime);
  border-color: var(--lime-soft);
  font-variant-numeric: tabular-nums;
}

/* ---------- 使用场景 ---------- */
.page-about .about-personas {
  display: grid;
  gap: 14px;
  margin: clamp(20px, 2.8vw, 30px) 0 0;
}

.page-about .about-persona {
  padding: clamp(18px, 2.2vw, 24px);
}

.page-about .about-persona-tag {
  display: inline-block;
  margin-bottom: 12px;
}

.page-about .about-persona h3 {
  margin: 0 0 10px;
  font-size: clamp(17px, 1.5vw, 22px);
}

.page-about .about-persona p:last-child {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--c-steel);
}

/* ---------- 行动指引 ---------- */
.page-about .about-cta-line {
  max-width: 40em;
  margin: clamp(26px, 3.4vw, 40px) 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--wire-line);
  font-size: 15px;
  line-height: 1.9;
  color: var(--c-steel);
}

.page-about .about-cta-line a {
  color: var(--c-lime);
  text-decoration: none;
  border-bottom: 1px solid var(--lime-soft);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-cta-line a:hover,
.page-about .about-cta-line a:focus-visible {
  color: var(--c-orange);
  border-bottom-color: var(--orange-soft);
}

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

/* ---------- 平板及以上 ---------- */
@media (min-width: 641px) {
  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-pair {
    grid-template-columns: minmax(0, 300px) minmax(0, 1fr);
    align-items: start;
  }
}

/* ---------- 桌面分屏 ---------- */
@media (min-width: 1024px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(36px, 4.6vw, 76px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    padding: 4px 0 4px 18px;
    border-bottom: 0;
    border-left: 1px solid var(--wire-line);
  }

  .page-about .about-rail-list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail-list a {
    width: 100%;
    justify-content: flex-start;
    padding: 7px 10px;
    border-color: transparent;
    background: transparent;
  }

  .page-about .about-rail-list a:hover,
  .page-about .about-rail-list a:focus-visible {
    background: rgba(183, 255, 60, 0.06);
  }

  .page-about .about-strip {
    gap: 0;
  }

  .page-about .about-personas {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 1600px) {
  .page-about {
    --about-rail-w: 240px;
  }

  .page-about .about-strip {
    padding: clamp(24px, 2.2vw, 34px);
  }

  .page-about .about-strip-cap {
    font-size: 14px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail-list a,
  .page-about .about-cta-line a {
    transition: none;
    transform: none;
  }
}