.page-about {
  --ab-track: clamp(24px, 6vw, 84px);
  --ab-block: clamp(44px, 8vw, 112px);
  position: relative;
  overflow-x: clip;
  background: var(--ink);
  color: var(--muted);
}

.page-about::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: min(1500px, 145vh);
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 96px 96px;
  opacity: .7;
  pointer-events: none;
  z-index: 0;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, .9) 0%, rgba(0, 0, 0, 0) 86%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, .9) 0%, rgba(0, 0, 0, 0) 86%);
}

.page-about > * {
  position: relative;
  z-index: 1;
}

/* 面包屑 */
.page-about .crumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 18px 0 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .crumbs a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .crumbs a:hover,
.page-about .crumbs a:focus-visible {
  color: var(--neon);
  border-bottom-color: var(--neon);
}

.page-about .crumbs span[aria-current] {
  color: var(--paper);
}

/* 首屏 */
.page-about .ab-hero {
  padding: clamp(22px, 4vw, 42px) 0 clamp(30px, 5vw, 58px);
}

.page-about .ab-hero__inner {
  display: grid;
  gap: clamp(22px, 4vw, 42px);
  align-items: center;
}

.page-about .ab-hero h1 {
  margin: 14px 0 0;
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(30px, 5.4vw, 58px);
  line-height: 1.12;
  letter-spacing: -.012em;
  color: var(--paper);
}

.page-about .ab-hero__lead {
  margin: clamp(14px, 2vw, 22px) 0 0;
  max-width: 36em;
  font-size: 17px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .ab-hero__media {
  margin: 0;
  position: relative;
  border: 1px solid var(--line);
  background: var(--panel);
  overflow: hidden;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 44px), calc(100% - 44px) 100%, 0 100%);
}

.page-about .ab-hero__media::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 96px;
  height: 3px;
  background: var(--neon);
}

.page-about .ab-hero__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  filter: saturate(.92) contrast(1.06);
}

/* 坐标条 */
.page-about .ab-coord {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(14, 42, 34, .6), rgba(8, 13, 18, 0));
}

.page-about .ab-coord__inner {
  display: flex;
  flex-wrap: wrap;
  gap: 12px clamp(20px, 4vw, 56px);
  padding: 16px 0;
}

.page-about .ab-coord__item {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 0;
}

.page-about .ab-coord__item .coord-key {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--deep);
}

.page-about .ab-coord__item .coord-val {
  font-family: var(--mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

/* 主体刻度动线 */
.page-about .ab-body {
  padding: clamp(44px, 7vw, 96px) 0 clamp(50px, 8vw, 104px);
}

.page-about .ab-flow {
  position: relative;
  padding-left: var(--ab-track);
}

.page-about .ab-flow::before {
  content: "";
  position: absolute;
  left: var(--ab-track);
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--neon) 0%, var(--deep) 10%, var(--line) 42%, var(--line) 100%);
  opacity: .85;
}

.page-about .ab-chapter {
  position: relative;
  padding-left: clamp(16px, 2.6vw, 38px);
  padding-bottom: var(--ab-block);
}

.page-about .ab-chapter--last {
  padding-bottom: clamp(20px, 3vw, 36px);
}

.page-about .ab-chapter__num {
  position: absolute;
  top: 0;
  left: 0;
  transform: translateX(-100%);
  padding-right: clamp(6px, 1.2vw, 16px);
  font-family: var(--mono);
  font-size: clamp(12px, 1.4vw, 17px);
  font-weight: 700;
  letter-spacing: .1em;
  line-height: 1.9;
  color: var(--neon);
  white-space: nowrap;
  margin: 0;
}

.page-about .ab-chapter__title {
  margin: 0 0 clamp(12px, 1.8vw, 18px);
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(21px, 3.1vw, 34px);
  line-height: 1.24;
  letter-spacing: -.006em;
  color: var(--paper);
}

.page-about .ab-chapter__text p {
  margin: 0 0 14px;
  max-width: 37em;
  font-size: 16px;
  line-height: 1.82;
  color: var(--muted);
}

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

/* 配图 */
.page-about .ab-figure {
  position: relative;
  margin: clamp(22px, 3vw, 34px) 0 0;
  max-width: 46em;
  border: 1px solid var(--line);
  background: var(--panel);
  overflow: hidden;
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  filter: saturate(.9) contrast(1.04);
}

.page-about .ab-figure figcaption {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 8px 14px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--paper);
  background: rgba(8, 13, 18, .82);
  border-top: 1px solid var(--line);
  border-right: 1px solid var(--line);
}

/* 三条线 */
.page-about .ab-lanes {
  display: grid;
  gap: clamp(14px, 2vw, 22px);
  margin-top: clamp(20px, 2.8vw, 30px);
}

.page-about .ab-lane {
  --lane: var(--neon);
  position: relative;
  padding: clamp(20px, 2.6vw, 28px);
  background: linear-gradient(155deg, var(--moss), var(--panel) 82%);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 24px), calc(100% - 24px) 100%, 0 100%);
}

.page-about .ab-lane:nth-child(2) {
  --lane: var(--deep);
}

.page-about .ab-lane:nth-child(3) {
  --lane: var(--orange);
}

.page-about .ab-lane::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 58px;
  height: 3px;
  background: var(--lane);
}

.page-about .ab-lane__tag {
  color: var(--lane) !important;
  margin: 0 0 12px;
}

.page-about .ab-lane__title {
  margin: 0 0 10px;
  font-family: var(--display);
  font-weight: 700;
  font-size: clamp(17px, 2.1vw, 20px);
  line-height: 1.35;
  color: var(--paper);
}

.page-about .ab-lane__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

/* 统计数字 */
.page-about .ab-stats {
  display: grid;
  gap: clamp(18px, 2.6vw, 28px);
  margin-top: clamp(24px, 3.4vw, 38px);
  padding-top: clamp(20px, 3vw, 32px);
  border-top: 1px solid var(--line);
}

.page-about .ab-stat__num {
  margin: 0;
  font-family: var(--mono);
  font-size: clamp(34px, 5vw, 54px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-stat__unit {
  margin-left: 6px;
  font-size: .4em;
  letter-spacing: 0;
  color: var(--neon);
}

.page-about .ab-stat__label {
  margin: 10px 0 0;
  max-width: 20em;
  font-size: 14px;
  line-height: 1.62;
  color: var(--muted);
}

/* 结尾指引 */
.page-about .ab-next {
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(14, 42, 34, .55), rgba(8, 13, 18, 0));
}

.page-about .ab-next__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: clamp(18px, 3vw, 32px);
  padding: clamp(30px, 5vw, 56px) 0 clamp(36px, 6vw, 68px);
}

.page-about .ab-next__title {
  margin: 12px 0 0;
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(20px, 3vw, 30px);
  line-height: 1.28;
  color: var(--paper);
}

.page-about .ab-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* 响应式 */
@media (min-width: 760px) {
  .page-about .ab-lanes {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 960px) {
  .page-about .ab-hero__inner {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: clamp(32px, 5vw, 64px);
  }

  .page-about .ab-figure {
    margin-left: calc(-1 * clamp(0px, 2vw, 28px));
  }
}

@media (max-width: 640px) {
  .page-about .ab-chapter__num {
    font-size: 11px;
    letter-spacing: .06em;
    padding-right: 5px;
  }

  .page-about .ab-chapter {
    padding-left: 12px;
  }

  .page-about .ab-hero__media {
    clip-path: polygon(0 0, 100% 0, 100% calc(100% - 28px), calc(100% - 28px) 100%, 0 100%);
  }

  .page-about .ab-figure figcaption {
    position: static;
    border-right: 0;
    border-top: 1px solid var(--line);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .crumbs a {
    transition: none;
  }
}
</main>