.page-about {
  --about-cut: 12px;
  --about-rule: rgba(90, 101, 112, 0.28);
  --about-rule-dark: rgba(242, 246, 248, 0.14);
  background: var(--c-deep);
  color: var(--c-spray);
}

/* ---------- 顶部 ---------- */

.page-about .about-top {
  background:
    linear-gradient(118deg, var(--c-deep) 0%, var(--c-deep) 62%, var(--c-abyss) 62%, var(--c-abyss) 100%);
  color: var(--c-spray);
  padding-bottom: var(--band);
}

.page-about .about-hero {
  padding: calc(var(--band) * 0.72) 0 0;
}

.page-about .about-top .breadcrumbs__list {
  color: rgba(242, 246, 248, 0.5);
}

.page-about .about-top .breadcrumbs__link {
  color: rgba(242, 246, 248, 0.76);
}

.page-about .about-hero__annot {
  margin: 1.75rem 0 0.85rem;
  font-family: var(--f-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.22em;
  color: var(--c-tide);
  text-transform: uppercase;
}

.page-about .about-hero__title {
  margin: 0 0 1.4rem;
  max-width: 17em;
  font-family: var(--f-sans);
  font-weight: 800;
  font-size: var(--fs-display);
  line-height: var(--lh-tight);
  letter-spacing: -0.015em;
  transform: skewX(-8deg);
  transform-origin: left bottom;
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 34em;
  font-size: var(--fs-base);
  line-height: var(--lh-body);
  color: rgba(242, 246, 248, 0.78);
}

.page-about .about-hero__meta {
  list-style: none;
  margin: 2.25rem 0 0;
  padding: 1.4rem 0 0;
  display: grid;
  gap: 1rem;
  border-top: 1px solid var(--about-rule-dark);
}

.page-about .about-hero__metaItem {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.page-about .about-hero__k {
  font-family: var(--f-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.18em;
  color: var(--c-rock);
}

.page-about .about-hero__v {
  font-size: var(--fs-base);
  font-weight: 600;
  color: var(--c-spray);
}

.page-about .about-visual {
  margin: 0;
}

.page-about .about-visual .media {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), 0 100%);
}

.page-about .about-visual .media__caption {
  margin-top: 0.75rem;
  font-size: var(--fs-xs);
  letter-spacing: 0.06em;
  color: rgba(242, 246, 248, 0.5);
}

/* ---------- 分区基础 ---------- */

.page-about .about-sec {
  padding: var(--band) 0;
}

.page-about .about-sec--bone {
  background: var(--c-bone);
  color: var(--c-ink);
}

.page-about .about-sec--deep {
  background: var(--c-deep);
  color: var(--c-spray);
}

.page-about .about-sec__head {
  margin-bottom: 1.75rem;
}

.page-about .about-sec__num {
  display: block;
  margin-bottom: 0.7rem;
  font-family: var(--f-mono);
  font-size: var(--fs-sm);
  font-weight: 700;
  letter-spacing: 0.24em;
  color: var(--c-clay);
}

.page-about .about-sec--deep .about-sec__num {
  color: rgba(242, 246, 248, 0.5);
}

.page-about .about-sec__title {
  margin: 0 0 0.9rem;
  max-width: 20em;
  font-family: var(--f-sans);
  font-weight: 800;
  font-size: var(--fs-xl);
  line-height: var(--lh-tight);
  letter-spacing: -0.01em;
  transform: skewX(-8deg);
  transform-origin: left center;
}

.page-about .about-sec__note {
  margin: 0;
  font-family: var(--f-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.2em;
  color: var(--c-rock);
  text-transform: uppercase;
}

.page-about .about-sec__lede {
  margin: 0 0 2rem;
  max-width: 34em;
  font-size: var(--fs-base);
  line-height: var(--lh-body);
}

.page-about .about-sec--bone .about-sec__lede {
  color: rgba(10, 16, 23, 0.82);
}

.page-about .about-sec--deep .about-sec__lede {
  color: rgba(242, 246, 248, 0.78);
}

.page-about .about-sec__lede + .about-sec__lede {
  margin-top: -0.75rem;
}

/* ---------- 时间线 ---------- */

.page-about .tl {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .tl__node {
  position: relative;
  display: grid;
  gap: 0.55rem 2rem;
  padding: clamp(1.5rem, 4.5vw, 2.5rem) 0;
  border-top: 1px solid var(--about-rule);
}

.page-about .about-sec--deep .tl__node {
  border-top-color: var(--about-rule-dark);
}

.page-about .tl__year {
  margin: 0;
  font-family: var(--f-mono);
  font-size: clamp(2.5rem, 9vw, 3.75rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.035em;
  font-variant-numeric: tabular-nums;
  color: rgba(10, 16, 23, 0.22);
  transition: color 0.3s var(--ease);
}

.page-about .about-sec--deep .tl__year {
  color: rgba(242, 246, 248, 0.32);
}

.page-about .tl__node:hover .tl__year,
.page-about .tl__node:focus-within .tl__year {
  color: var(--c-signal);
}

.page-about .tl__stage {
  margin: 0 0 0.5rem;
  font-family: var(--f-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-moss);
}

.page-about .about-sec--deep .tl__stage {
  color: var(--c-neon);
}

.page-about .tl__title {
  margin: 0 0 0.75rem;
  max-width: 22em;
  font-family: var(--f-sans);
  font-weight: 700;
  font-size: var(--fs-lg);
  line-height: 1.25;
}

.page-about .tl__text {
  margin: 0;
  max-width: 34em;
  font-size: var(--fs-base);
  line-height: var(--lh-body);
}

.page-about .about-sec--bone .tl__text {
  color: rgba(10, 16, 23, 0.8);
}

.page-about .about-sec--deep .tl__text {
  color: rgba(242, 246, 248, 0.76);
}

.page-about .tl__more {
  margin-top: 0.85rem;
}

.page-about .tl__summary {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.3rem 0;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--c-tide);
  cursor: pointer;
  list-style: none;
  transition: color 0.22s var(--ease);
}

.page-about .tl__summary::-webkit-details-marker {
  display: none;
}

.page-about .tl__summary::before {
  content: "+";
  font-family: var(--f-mono);
  font-size: 1rem;
  line-height: 1;
  color: var(--c-signal);
  transition: transform 0.22s var(--ease);
}

.page-about .tl__more[open] .tl__summary::before {
  transform: rotate(45deg);
}

.page-about .about-sec--deep .tl__summary {
  color: rgba(242, 246, 248, 0.72);
}

.page-about .about-sec--deep .tl__summary:hover {
  color: var(--c-spray);
}

.page-about .tl__extra {
  margin: 0.6rem 0 0;
  max-width: 32em;
  padding-left: 0.9rem;
  border-left: 3px solid var(--c-clay);
  font-size: var(--fs-sm);
  line-height: var(--lh-body);
  color: rgba(10, 16, 23, 0.7);
}

.page-about .about-sec--deep .tl__extra {
  color: rgba(242, 246, 248, 0.66);
}

/* ---------- 数据带 ---------- */

.page-about .about-band {
  background: var(--c-abyss);
  color: var(--c-spray);
  padding: clamp(2.25rem, 6vw, 4rem) 0;
}

.page-about .about-band__grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(9.5rem, 1fr));
  gap: 1px;
  background: var(--about-rule-dark);
  border: 1px solid var(--about-rule-dark);
  clip-path: polygon(0 var(--about-cut), 100% 0, 100% 100%, 0 calc(100% - var(--about-cut)));
}

.page-about .about-band__cell {
  background: var(--c-abyss);
  padding: 1.3rem 1.1rem 1.15rem;
}

.page-about .about-band__num {
  font-family: var(--f-mono);
  font-size: clamp(2rem, 5.4vw, 2.9rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: var(--c-spray);
}

.page-about .about-band__unit {
  margin-left: 0.3rem;
  font-size: var(--fs-sm);
  color: var(--c-tide);
}

.page-about .about-band__label {
  display: block;
  margin-top: 0.6rem;
  font-size: var(--fs-sm);
  line-height: 1.55;
  color: rgba(242, 246, 248, 0.62);
}

/* ---------- 团队岗位 ---------- */

.page-about .about-roles {
  list-style: none;
  margin: 0 0 1.75rem;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--about-rule);
  border: 1px solid var(--about-rule);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), 0 100%);
}

.page-about .about-role {
  position: relative;
  background: var(--c-bone);
  padding: 1.4rem 1.2rem 1.3rem;
  transition: background 0.25s var(--ease);
}

.page-about .about-role::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--c-signal);
  transform: scaleY(0);
  transform-origin: top center;
  transition: transform 0.25s var(--ease);
}

.page-about .about-role:hover {
  background: #E6DFD2;
}

.page-about .about-role:hover::before {
  transform: scaleY(1);
}

.page-about .about-role__name {
  margin: 0 0 0.5rem;
  font-size: var(--fs-md);
  font-weight: 700;
  color: var(--c-ink);
}

.page-about .about-role__desc {
  margin: 0;
  font-size: var(--fs-sm);
  line-height: var(--lh-body);
  color: rgba(10, 16, 23, 0.72);
}

.page-about .about-pace {
  display: flex;
  align-items: flex-start;
  gap: 0.55rem;
  margin: 0;
  padding: 1rem 1.1rem;
  border-left: 3px solid var(--c-clay);
  background: rgba(90, 101, 112, 0.09);
  font-size: var(--fs-sm);
  line-height: var(--lh-body);
  color: rgba(10, 16, 23, 0.8);
}

.page-about .about-pace__dot {
  flex: none;
  width: 8px;
  height: 8px;
  margin-top: 0.5rem;
  border-radius: 50%;
  background: var(--c-neon);
  box-shadow: 0 0 0 3px rgba(155, 229, 100, 0.18);
  animation: about-pulse 3s ease-in-out infinite;
}

@keyframes about-pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.35; transform: scale(0.78); }
}

/* ---------- 合作生态 ---------- */

.page-about .about-split {
  display: grid;
  gap: 2rem;
}

.page-about .about-split__body .about-sec__lede:last-of-type {
  margin-bottom: 1.4rem;
}

.page-about .about-split__figure {
  margin: 0;
}

.page-about .about-split__figure .media {
  clip-path: polygon(0 var(--about-cut), 100% 0, 100% 100%, 0 calc(100% - var(--about-cut)));
}

.page-about .about-split__figure .media__caption {
  margin-top: 0.7rem;
  font-size: var(--fs-xs);
  color: rgba(242, 246, 248, 0.5);
}

.page-about .about-chips {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* ---------- 四件事与行动 ---------- */

.page-about .about-sec--last {
  padding-bottom: calc(var(--band) * 1.1);
}

.page-about .about-pledge {
  list-style: none;
  margin: 0 0 2.5rem;
  padding: 0;
  display: grid;
  gap: 1.25rem;
}

.page-about .about-pledge__item {
  position: relative;
  padding: 1.1rem 1.1rem 1.1rem 1.4rem;
  border-left: 3px solid rgba(90, 101, 112, 0.32);
  transition: border-color 0.25s var(--ease), background 0.25s var(--ease);
}

.page-about .about-pledge__item:hover {
  border-left-color: var(--c-signal);
  background: rgba(255, 107, 44, 0.06);
}

.page-about .about-pledge__num {
  display: block;
  margin-bottom: 0.45rem;
  font-family: var(--f-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.2em;
  color: var(--c-rock);
}

.page-about .about-pledge__title {
  margin: 0 0 0.45rem;
  font-size: var(--fs-md);
  font-weight: 700;
  color: var(--c-ink);
}

.page-about .about-pledge__text {
  margin: 0;
  max-width: 30em;
  font-size: var(--fs-sm);
  line-height: var(--lh-body);
  color: rgba(10, 16, 23, 0.74);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1.25rem;
}

.page-about .about-cta__link {
  font-size: var(--fs-sm);
  color: var(--c-tide);
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-hero__meta {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about .tl__node {
    grid-template-columns: 10.5rem minmax(0, 1fr);
    align-items: start;
  }

  .page-about .tl__node::after {
    content: "";
    position: absolute;
    top: 1.6rem;
    left: 9.5rem;
    width: 1.4rem;
    height: 1.4rem;
    border-top: 1px solid var(--c-clay);
    border-right: 1px solid var(--c-clay);
    opacity: 0.55;
    transform: skewX(-14deg);
    transition: opacity 0.25s var(--ease), border-color 0.25s var(--ease);
  }

  .page-about .tl__node:hover::after,
  .page-about .tl__node:focus-within::after {
    border-color: var(--c-signal);
    opacity: 1;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
    gap: 3rem;
  }

  .page-about .about-pledge {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.25rem 2rem;
  }
}

@media (min-width: 1100px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 4rem;
  }

  .page-about .tl__node {
    grid-template-columns: 12rem minmax(0, 1fr);
  }

  .page-about .tl__node::after {
    left: 11rem;
  }
}

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

  .page-about .tl__year,
  .page-about .about-role,
  .page-about .about-role::before,
  .page-about .tl__summary::before,
  .page-about .about-pledge__item,
  .page-about .tl__node::after {
    transition: none;
  }
}