.page-about {
  --about-paper-body: #3D342D;
  --about-paper-line: #D8CBB6;
  --about-gap: clamp(16px, 2.6vw, 28px);
  display: block;
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: 26px;
  padding-bottom: 4px;
}
.page-about .about-crumbs .crumbs {
  font-size: .8125rem;
  letter-spacing: .04em;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  background:
    radial-gradient(120% 90% at 88% -10%, rgba(53, 240, 208, .10), transparent 58%),
    radial-gradient(90% 80% at 2% 108%, rgba(138, 108, 255, .12), transparent 62%),
    var(--ink-blue-base);
  border-bottom: 1px solid var(--line-dark);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(147, 164, 196, .055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(147, 164, 196, .055) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(120% 78% at 62% 0%, #000 0%, transparent 74%);
  mask-image: radial-gradient(120% 78% at 62% 0%, #000 0%, transparent 74%);
  pointer-events: none;
}
.page-about .about-hero__inner {
  padding-top: 34px;
  padding-bottom: clamp(48px, 7vw, 78px);
}
.page-about .about-hero__title {
  margin: 14px 0 0;
  font-size: clamp(2rem, 5.4vw, 3.6rem);
  line-height: 1.13;
  font-weight: 800;
  letter-spacing: -0.012em;
  color: var(--pure-white);
  max-width: 22ch;
}
.page-about .about-hero__lede {
  margin: 22px 0 0;
  max-width: 64ch;
  font-size: clamp(.9875rem, 1.5vw, 1.125rem);
  line-height: 1.82;
  color: var(--steel-text);
}
.page-about .about-hero__figure {
  position: relative;
  margin: clamp(34px, 5vw, 52px) 0 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line-dark);
  background: var(--midnight-panel);
}
.page-about .about-hero__figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(180deg, rgba(255, 255, 255, .03) 0 1px, transparent 1px 4px);
  pointer-events: none;
}
.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

/* ---------- 章节外壳 ---------- */
.page-about .about-sec {
  padding: clamp(52px, 8vw, 98px) 0;
  position: relative;
}
.page-about .about-sec--paper {
  background: var(--cream-paper);
  color: var(--about-paper-body);
}
.page-about .about-sec--dark {
  background: var(--ink-blue-base);
  color: var(--steel-text);
  border-top: 1px solid var(--line-darker);
  border-bottom: 1px solid var(--line-darker);
}
.page-about .about-sec--dark::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(53, 240, 208, .28), transparent);
  pointer-events: none;
}

/* ---------- 章节标题 ---------- */
.page-about .about-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px 18px;
  align-items: start;
  margin-bottom: clamp(26px, 4vw, 42px);
}
.page-about .about-head .chapter-no {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 5.4vw, 3.2rem);
  font-weight: 800;
  line-height: .92;
  letter-spacing: -0.03em;
  color: var(--fluoro-cyan);
}
.page-about .about-sec--paper .about-head .chapter-no {
  color: var(--deep-brown-black);
  opacity: .34;
}
.page-about .about-head__text h2 {
  margin: 8px 0 0;
  font-size: clamp(1.45rem, 3.4vw, 2.25rem);
  line-height: 1.22;
  font-weight: 800;
  letter-spacing: -0.01em;
}
.page-about .about-sec--paper .about-head__text h2 {
  color: var(--deep-brown-black);
}
.page-about .about-sec--dark .about-head__text h2 {
  color: var(--pure-white);
}
.page-about .about-head__lede {
  margin: 12px 0 0;
  max-width: 56ch;
  font-size: .9875rem;
  line-height: 1.8;
}
.page-about .about-sec--paper .about-head__lede {
  color: var(--about-paper-body);
}
.page-about .about-sec--dark .about-head__lede {
  color: var(--steel-text);
}

/* ---------- 正文 ---------- */
.page-about .about-prose {
  max-width: 68ch;
}
.page-about .about-prose--wide {
  max-width: 76ch;
}
.page-about .about-prose p {
  margin: 0 0 1.2em;
  font-size: .9875rem;
  line-height: 1.85;
}
.page-about .about-prose p:last-child {
  margin-bottom: 0;
}
.page-about .about-sec--paper .about-prose p {
  color: var(--about-paper-body);
}
.page-about .about-sec--dark .about-prose p {
  color: var(--steel-text);
}

/* ---------- 01 数据条 ---------- */
.page-about .about-facts {
  list-style: none;
  margin: clamp(30px, 4.5vw, 46px) 0 0;
  padding: clamp(20px, 3vw, 28px) 0 0;
  border-top: 1px solid var(--about-paper-line);
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}
.page-about .about-fact {
  display: flex;
  align-items: baseline;
  gap: 12px;
}
.page-about .about-fact__num {
  font-family: var(--font-mono);
  font-size: clamp(1.85rem, 4.4vw, 2.6rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.025em;
  color: var(--deep-brown-black);
}
.page-about .about-fact__lab {
  font-size: .875rem;
  color: var(--about-paper-body);
  letter-spacing: .02em;
}

/* ---------- 02 分栏 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 42px);
  align-items: start;
}

/* ---------- 图片容器 ---------- */
.page-about .about-media {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line-dark);
  background: var(--midnight-panel);
}
.page-about .about-sec--paper .about-media {
  border-color: var(--about-paper-line);
  background: #EBE2D3;
}
.page-about .about-media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .about-media--side img {
  aspect-ratio: 3 / 2;
}
.page-about .about-media--wide img {
  aspect-ratio: 12 / 7;
}
.page-about .about-media--wide {
  margin-top: clamp(30px, 4.5vw, 46px);
}
.page-about .about-sec--paper .figure-caption {
  color: #6B5D50;
}

/* ---------- 02 数据网格 ---------- */
.page-about .about-metrics {
  list-style: none;
  margin: clamp(34px, 5vw, 52px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
.page-about .about-metric {
  position: relative;
  padding: 22px 20px 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line-dark);
  background: linear-gradient(158deg, rgba(18, 30, 54, .94), rgba(11, 18, 32, .72));
  transition: transform .2s ease, border-color .2s ease;
}
.page-about .about-metric:hover {
  transform: translateY(-2px);
  border-color: rgba(53, 240, 208, .42);
}
.page-about .about-metric__num {
  font-family: var(--font-mono);
  font-size: clamp(2.1rem, 4.6vw, 2.9rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.025em;
  color: var(--fluoro-cyan);
}
.page-about .about-metric__unit {
  margin-left: 5px;
  font-size: .9rem;
  color: var(--steel-text);
}
.page-about .about-metric__text {
  margin: 12px 0 0;
  font-size: .9rem;
  line-height: 1.72;
  color: var(--steel-text);
}

/* ---------- 03 处理流程 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: clamp(30px, 4.5vw, 44px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
.page-about .about-step {
  padding: 22px 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--about-paper-line);
  background: rgba(255, 255, 255, .5);
}
.page-about .about-step__no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: var(--radius-pill);
  background: var(--deep-brown-black);
  color: var(--cream-paper);
  font-family: var(--font-mono);
  font-size: .8125rem;
  font-weight: 700;
  letter-spacing: .04em;
}
.page-about .about-step h3 {
  margin: 14px 0 0;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--deep-brown-black);
}
.page-about .about-step p {
  margin: 8px 0 0;
  font-size: .9rem;
  line-height: 1.75;
  color: var(--about-paper-body);
}

/* ---------- 04 时间线 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
.page-about .about-tl {
  outline: none;
}
.page-about .about-tl__card {
  height: 100%;
  padding: 20px 18px 22px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line-dark);
  background: linear-gradient(170deg, rgba(18, 30, 54, .96), rgba(11, 18, 32, .8));
  transition: transform .2s ease, border-color .2s ease;
}
.page-about .about-tl:hover .about-tl__card,
.page-about .about-tl:focus-within .about-tl__card {
  transform: translateY(-2px);
  border-color: rgba(53, 240, 208, .42);
}
.page-about .about-tl__year {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--fluoro-cyan);
}
.page-about .about-tl__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--fluoro-cyan);
  flex: 0 0 auto;
}
.page-about .about-tl--d .about-tl__dot {
  background: var(--signal-orange);
  box-shadow: 0 0 0 0 rgba(255, 122, 47, .6);
  animation: about-pulse 1.6s ease-out infinite;
}
.page-about .about-tl__title {
  margin: 12px 0 0;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--pure-white);
}
.page-about .about-tl__desc {
  margin: 10px 0 0;
  font-size: .9rem;
  line-height: 1.75;
  color: var(--steel-text);
}

@keyframes about-pulse {
  0% { box-shadow: 0 0 0 0 rgba(255, 122, 47, .55); }
  70% { box-shadow: 0 0 0 10px rgba(255, 122, 47, 0); }
  100% { box-shadow: 0 0 0 0 rgba(255, 122, 47, 0); }
}

.page-about .about-tail {
  margin: clamp(30px, 4.5vw, 44px) 0 0;
  max-width: 68ch;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--steel-text);
}

/* ---------- 05 反馈入口 ---------- */
.page-about .about-lanes {
  list-style: none;
  margin: clamp(30px, 4.5vw, 44px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}
.page-about .about-lane a {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  grid-template-rows: auto auto;
  gap: 6px 16px;
  align-items: center;
  padding: 20px 20px 20px 22px;
  border-radius: var(--radius-md);
  border: 1px solid var(--about-paper-line);
  background: rgba(255, 255, 255, .58);
  text-decoration: none;
  color: inherit;
  transition: transform .2s ease, border-color .2s ease, background-color .2s ease;
}
.page-about .about-lane a:hover,
.page-about .about-lane a:focus-visible {
  transform: translateY(-2px);
  border-color: rgba(53, 240, 208, .7);
  background: rgba(255, 255, 255, .82);
  outline: none;
}
.page-about .about-lane a:focus-visible {
  outline: 2px solid var(--electric-violet);
  outline-offset: 2px;
}
.page-about .about-lane__k {
  grid-column: 1;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--deep-brown-black);
}
.page-about .about-lane__v {
  grid-column: 1;
  font-size: .875rem;
  line-height: 1.7;
  color: var(--about-paper-body);
}
.page-about .about-lane__arrow {
  grid-column: 2;
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: 1.125rem;
  color: var(--deep-brown-black);
  transition: transform .2s ease;
}
.page-about .about-lane a:hover .about-lane__arrow,
.page-about .about-lane a:focus-visible .about-lane__arrow {
  transform: translateX(4px);
}

/* ---------- 06 人群与呼叫 ---------- */
.page-about .about-split--reverse {
  align-items: start;
}
.page-about .about-callout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line-dark);
  background: var(--line-dark);
}
.page-about .about-callout__item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px 20px;
  background: var(--midnight-panel);
}
.page-about .about-callout__num {
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 4vw, 2.35rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.025em;
  color: var(--fluoro-cyan);
}
.page-about .about-callout__unit {
  margin-left: 3px;
  font-size: .875rem;
  font-weight: 600;
}
.page-about .about-callout__lab {
  font-size: .8125rem;
  letter-spacing: .02em;
  color: var(--steel-text);
}

.page-about .about-cta {
  margin-top: clamp(34px, 5vw, 52px);
  padding: clamp(22px, 3vw, 30px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--line-dark);
  background: linear-gradient(140deg, rgba(138, 108, 255, .14), rgba(53, 240, 208, .08));
  display: grid;
  gap: 18px;
}
.page-about .about-cta__text {
  margin: 0;
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--pure-white);
}
.page-about .about-cta__row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.page-about .about-cta__row .btn {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

/* ---------- 桌面增强 ---------- */
@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }
  .page-about .about-fact {
    flex-direction: column;
    gap: 10px;
  }
  .page-about .about-metrics {
    grid-template-columns: 1.18fr .82fr;
  }
  .page-about .about-meter-row {
    display: contents;
  }
  .page-about .about-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-lanes {
    gap: 14px;
  }
}

@media (min-width: 900px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    gap: clamp(32px, 4vw, 56px);
  }
  .page-about .about-split--reverse {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
  }
  .page-about .about-head {
    grid-template-columns: minmax(0, 96px) minmax(0, 1fr);
    gap: 18px 26px;
  }
  .page-about .about-head .chapter-no {
    font-size: clamp(2.6rem, 4.4vw, 3.6rem);
  }
  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .page-about .about-timeline {
    grid-template-columns: .85fr 1fr 1.3fr 1.7fr;
    gap: 16px;
    align-items: end;
  }
  .page-about .about-tl__card {
    padding: 24px 20px 26px;
  }
  .page-about .about-tl--c .about-tl__title,
  .page-about .about-tl--d .about-tl__title {
    font-size: 1.15rem;
  }
}

@media (hover: hover) and (pointer: fine) and (min-width: 1024px) {
  .page-about .about-tl__desc {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    margin-top: 0;
    transition: max-height .34s ease, opacity .3s ease, margin-top .3s ease;
  }
  .page-about .about-tl:hover .about-tl__desc,
  .page-about .about-tl:focus-within .about-tl__desc {
    max-height: 240px;
    opacity: 1;
    margin-top: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl--d .about-tl__dot {
    animation: none;
  }
  .page-about .about-metric,
  .page-about .about-tl__card,
  .page-about .about-lane a,
  .page-about .about-lane__arrow {
    transition: none;
  }
}
</main>