.page-about {
  --about-gap: 44px;
  --about-axis: 24px;
  --about-node: -20px;
  --about-plate: rgba(217, 205, 182, .06);
  padding-top: clamp(20px, 4vw, 40px);
}

.page-about .about-wrap {
  width: 100%;
  max-width: var(--frame);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
  padding-bottom: clamp(48px, 9vw, 96px);
}

/* 面包屑 */
.page-about .breadcrumb {
  margin-bottom: clamp(16px, 3vw, 28px);
}

.page-about .breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0 6px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: .08em;
  color: var(--rock-400);
}

.page-about .breadcrumb li {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.page-about .breadcrumb li + li::before {
  content: "/";
  color: var(--grid-600);
}

.page-about .breadcrumb a {
  color: var(--moss-500);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--pulse-400);
  border-bottom-color: var(--pulse-400);
}

.page-about .breadcrumb [aria-current="page"] {
  color: var(--rock-400);
}

/* 首屏 */
.page-about .about-mast {
  position: relative;
  overflow: hidden;
  border-bottom: var(--rule);
  padding: clamp(24px, 5vw, 56px) 0 clamp(28px, 5vw, 56px);
}

.page-about .about-mast::before {
  content: "";
  position: absolute;
  inset: -1px -1px 0 -1px;
  background-image:
    linear-gradient(to right, rgba(30, 59, 51, .55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30, 59, 51, .55) 1px, transparent 1px);
  background-size: 24px 24px;
  opacity: .5;
  pointer-events: none;
  -webkit-mask-image: linear-gradient(to bottom, #000 0%, rgba(0, 0, 0, .35) 70%, transparent 100%);
  mask-image: linear-gradient(to bottom, #000 0%, rgba(0, 0, 0, .35) 70%, transparent 100%);
}

.page-about .about-mast__grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 5vw, 48px);
}

.page-about .about-mast__lead .eyebrow {
  margin: 0 0 16px;
  color: var(--pulse-400);
}

.page-about .about-mast__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(32px, 7vw, 64px);
  line-height: 1.06;
  letter-spacing: .01em;
  color: var(--mist-100);
  transform: skewX(-4deg);
  transform-origin: left bottom;
}

.page-about .about-mast__title-accent {
  display: block;
  color: var(--pulse-400);
  padding-right: .12em;
}

.page-about .about-mast__lede {
  margin: clamp(18px, 3vw, 26px) 0 0;
  max-width: 56ch;
  font-size: var(--fs-17);
  line-height: 1.85;
  color: var(--mist-100);
}

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

.page-about .about-mast__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 20px;
  align-content: end;
  border-top: var(--rule);
  padding-top: clamp(20px, 3vw, 28px);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(40px, 8vw, 64px);
  line-height: .95;
  letter-spacing: .01em;
  font-weight: 700;
}

.page-about .about-stat__num--pulse {
  color: var(--pulse-400);
}

.page-about .about-stat__num--amber {
  color: var(--amber-400);
}

.page-about .about-stat__label {
  font-size: var(--fs-13);
  line-height: 1.6;
  color: var(--rock-400);
}

.page-about .about-stat__foot {
  grid-column: 1 / -1;
  margin: 4px 0 0;
  padding-top: 12px;
  border-top: var(--rule);
  font-size: var(--fs-12);
  letter-spacing: .1em;
  color: var(--moss-500);
}

/* 纵向时间轴 */
.page-about .about-track {
  position: relative;
  padding-left: var(--about-gap);
  padding-top: clamp(32px, 6vw, 64px);
}

.page-about .about-track::before {
  content: "";
  position: absolute;
  left: var(--about-axis);
  top: 0;
  bottom: clamp(24px, 5vw, 48px);
  width: 1px;
  background: linear-gradient(to bottom, var(--grid-600) 0%, var(--grid-600) 88%, transparent 100%);
}

.page-about .about-step {
  position: relative;
  padding-bottom: clamp(40px, 7vw, 72px);
}

.page-about .about-step::before {
  content: "";
  position: absolute;
  left: var(--about-node);
  top: 26px;
  width: 11px;
  height: 11px;
  transform: translateX(-50%);
  border: 1px solid var(--moss-500);
  border-radius: 50%;
  background: var(--ink-900);
}

.page-about .about-step--done::before {
  border-color: var(--pulse-400);
  background: var(--pulse-400);
  box-shadow: 0 0 0 4px rgba(53, 240, 168, .14);
}

.page-about .about-step--talk::before {
  border-color: var(--amber-400);
  background: var(--amber-400);
  box-shadow: 0 0 0 4px rgba(242, 178, 55, .14);
}

/* 展览标签牌 */
.page-about .about-label {
  background: var(--about-plate);
  border: var(--rule);
  border-left: 2px solid var(--grid-600);
  padding: clamp(18px, 3.4vw, 32px);
}

.page-about .about-label__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 14px;
}

.page-about .about-label__no {
  font-size: var(--fs-13);
  letter-spacing: .16em;
  color: var(--rock-400);
}

.page-about .about-label__title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(21px, 4vw, 28px);
  line-height: 1.25;
  letter-spacing: .01em;
  color: var(--mist-100);
}

.page-about .about-label__text {
  margin: 0;
  max-width: 68ch;
  font-size: var(--fs-15);
  line-height: 1.95;
  color: var(--mist-100);
}

.page-about .about-label__text + .about-label__text {
  margin-top: 16px;
}

.page-about .about-label__text a {
  color: var(--pulse-400);
  text-decoration: none;
  border-bottom: 1px solid var(--pulse-700);
}

.page-about .about-label__text a:hover,
.page-about .about-label__text a:focus-visible {
  border-bottom-color: var(--pulse-400);
}

/* 分段切换 */
.page-about .about-tabs {
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .segmented {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border: var(--rule);
  background: var(--ink-800);
}

.page-about .segmented__btn {
  appearance: none;
  -webkit-appearance: none;
  border: 0;
  border-right: var(--rule);
  background: transparent;
  color: var(--rock-400);
  font-family: var(--font-body);
  font-size: var(--fs-13);
  letter-spacing: .04em;
  min-height: 48px;
  padding: 0 8px;
  cursor: pointer;
  transition: background 200ms var(--ease), color 200ms var(--ease);
}

.page-about .segmented__btn:last-child {
  border-right: 0;
}

.page-about .segmented__btn:hover {
  color: var(--mist-100);
}

.page-about .segmented__btn[aria-selected="true"] {
  background: var(--pulse-400);
  color: var(--ink-900);
  font-weight: 700;
}

.page-about .segmented__btn:focus-visible {
  outline: 2px solid var(--pulse-400);
  outline-offset: 2px;
}

.page-about .segment-panel {
  padding: 18px 0 0;
  animation: about-fade 120ms var(--ease) both;
}

.page-about .segment-panel[hidden] {
  display: none;
}

.page-about .segment-panel p {
  margin: 0;
  font-size: var(--fs-15);
  line-height: 1.95;
  color: var(--mist-100);
}

@keyframes about-fade {
  from { opacity: 0; transform: translateX(6px); }
  to { opacity: 1; transform: translateX(0); }
}

/* 图片与标签牌图注 */
.page-about .about-figure {
  margin: clamp(20px, 3vw, 28px) 0 0;
  border: var(--rule);
  background: var(--ink-800);
}

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

.page-about .about-figure__cap {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 10px;
  padding: 10px 12px;
  border-top: var(--rule);
  font-size: var(--fs-12);
  line-height: 1.7;
  color: var(--rock-400);
  background: rgba(217, 205, 182, .05);
}

.page-about .about-figure__cap .mono {
  font-size: var(--fs-12);
  letter-spacing: .12em;
  color: var(--amber-400);
}

.page-about .about-figure--wide {
  margin-top: clamp(24px, 4vw, 36px);
}

/* 版本刻度条 */
.page-about .about-scale {
  display: flex;
  gap: 2px;
  height: 6px;
  margin: clamp(22px, 3vw, 30px) 0 8px;
}

.page-about .about-scale__seg {
  display: block;
  height: 100%;
}

.page-about .about-scale__seg--a { flex: 2; background: var(--moss-500); }
.page-about .about-scale__seg--b { flex: 3; background: var(--pulse-700); }
.page-about .about-scale__seg--c { flex: 3; background: var(--pulse-400); }
.page-about .about-scale__seg--d { flex: 2; background: var(--amber-400); }

.page-about .about-scale__labels {
  display: flex;
  gap: 2px;
  font-size: var(--fs-12);
  letter-spacing: .08em;
  color: var(--rock-400);
}

.page-about .about-scale__labels span:nth-child(1) { flex: 2; }
.page-about .about-scale__labels span:nth-child(2) { flex: 3; }
.page-about .about-scale__labels span:nth-child(3) { flex: 3; }
.page-about .about-scale__labels span:nth-child(4) { flex: 2; }

/* 里程碑列表 */
.page-about .about-miles {
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
}

.page-about .about-mile {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 6px 12px;
  align-items: center;
  padding: 14px 12px;
  border-top: var(--rule);
  background: transparent;
  transition: background 200ms var(--ease), border-color 200ms var(--ease);
  outline: none;
}

.page-about .about-mile:last-child {
  border-bottom: var(--rule);
}

.page-about .about-mile:hover,
.page-about .about-mile:focus-visible,
.page-about .about-mile:focus-within {
  background: var(--ink-800);
  border-top-color: var(--pulse-700);
}

.page-about .about-mile:focus-visible {
  box-shadow: inset 0 0 0 1px var(--pulse-400);
}

.page-about .about-mile__ver {
  font-size: var(--fs-12);
  letter-spacing: .1em;
  color: var(--moss-500);
}

.page-about .about-mile__name {
  grid-column: 1;
  font-family: var(--font-display);
  font-size: var(--fs-17);
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--mist-100);
}

.page-about .about-mile .tag {
  grid-column: 2;
  grid-row: 1 / span 2;
  align-self: center;
}

.page-about .about-mile__note {
  grid-column: 1 / -1;
  margin: 0;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  font-size: var(--fs-13);
  line-height: 1.85;
  color: var(--rock-400);
  transition: max-height 240ms var(--ease), opacity 180ms var(--ease), margin-top 240ms var(--ease);
}

.page-about .about-mile:hover .about-mile__note,
.page-about .about-mile:focus .about-mile__note,
.page-about .about-mile:focus-within .about-mile__note {
  max-height: 160px;
  margin-top: 8px;
  opacity: 1;
}

/* 视觉规范区 */
.page-about .about-visual {
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .about-swatches {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.page-about .about-swatch {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  grid-template-rows: auto auto;
  gap: 2px 10px;
  align-items: center;
  padding: 10px;
  border: var(--rule);
  background: var(--ink-800);
}

.page-about .about-swatch__chip {
  grid-row: 1 / span 2;
  width: 30px;
  height: 30px;
  display: block;
  border: 1px solid rgba(232, 240, 234, .2);
}

.page-about .about-swatch__chip--ink { background: #07120F; }
.page-about .about-swatch__chip--pulse { background: #35F0A8; }
.page-about .about-swatch__chip--amber { background: #F2B237; }
.page-about .about-swatch__chip--moss { background: #4E7A5E; }
.page-about .about-swatch__chip--rock { background: #8C9A93; }
.page-about .about-swatch__chip--sand { background: #D9CDB6; }

.page-about .about-swatch__name {
  font-size: var(--fs-12);
  line-height: 1.4;
  color: var(--mist-100);
}

.page-about .about-swatch__hex {
  font-size: var(--fs-12);
  letter-spacing: .06em;
  color: var(--rock-400);
}

/* 结尾入口 */
.page-about .about-links {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .about-linkcard {
  position: relative;
  display: grid;
  gap: 4px;
  padding: 16px 44px 16px 16px;
  border: var(--rule);
  background: var(--ink-800);
  text-decoration: none;
  transition: border-color 200ms var(--ease), background 200ms var(--ease);
}

.page-about .about-linkcard:hover,
.page-about .about-linkcard:focus-visible {
  border-color: var(--pulse-400);
  background: var(--ink-700);
}

.page-about .about-linkcard:focus-visible {
  outline: 2px solid var(--pulse-400);
  outline-offset: 2px;
}

.page-about .about-linkcard__label {
  font-size: var(--fs-12);
  letter-spacing: .14em;
  color: var(--amber-400);
}

.page-about .about-linkcard__title {
  font-size: var(--fs-15);
  line-height: 1.6;
  color: var(--mist-100);
}

.page-about .about-linkcard__arrow {
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: var(--fs-21);
  color: var(--pulse-400);
  transition: transform 200ms var(--ease);
}

.page-about .about-linkcard:hover .about-linkcard__arrow {
  transform: translate(4px, -50%);
}

/* 响应式 */
@media (min-width: 600px) {
  .page-about .about-swatches {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-mast__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(32px, 5vw, 64px);
    align-items: end;
  }

  .page-about .about-step--done {
    display: grid;
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    gap: clamp(24px, 3vw, 40px);
    align-items: start;
  }

  .page-about .about-step--done > .about-figure {
    margin-top: 44px;
    position: sticky;
    top: calc(var(--bar-h) + 24px);
  }

  .page-about .about-step--done > .about-figure--wide {
    position: static;
  }

  .page-about .about-step--done .about-visual {
    margin-top: 44px;
  }

  .page-about .about-mile {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr) auto;
    gap: 8px 16px;
  }

  .page-about .about-mile__ver {
    grid-column: 1;
    grid-row: 1;
  }

  .page-about .about-mile__name {
    grid-column: 2;
    grid-row: 1;
  }

  .page-about .about-mile .tag {
    grid-column: 3;
    grid-row: 1;
  }

  .page-about .about-mile__note {
    grid-column: 1 / -1;
  }
}

@media (max-width: 700px) {
  .page-about {
    --about-gap: 26px;
    --about-axis: 13px;
    --about-node: -13px;
  }

  .page-about .about-track::before {
    bottom: 20px;
  }

  .page-about .about-step::before {
    width: 9px;
    height: 9px;
    top: 22px;
  }

  .page-about .about-label {
    border-left-width: 1px;
    border-left-color: var(--grid-600);
    border-top: 2px solid var(--pulse-700);
  }

  .page-about .about-mast__title {
    transform: skewX(-3deg);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .segment-panel {
    animation: none;
  }

  .page-about .about-mile__note,
  .page-about .about-mile,
  .page-about .about-linkcard,
  .page-about .about-linkcard__arrow {
    transition: none;
  }
}