.page-about {
  --tl-rail: 32px;
  --tl-gutter: 64px;
  --tl-accent: var(--c-cyan);
  position: relative;
  background: var(--c-void);
  overflow-x: clip;
}

@media (min-width: 760px) {
  .page-about {
    --tl-rail: 48px;
    --tl-gutter: 104px;
  }
}

.page-about .phase,
.page-about .tl-item,
.page-about .stat-band {
  scroll-margin-top: 92px;
}

/* ---------- 面包屑上下文 ---------- */
.page-about .breadcrumb {
  margin-top: 20px;
}

/* ---------- 首屏 ---------- */
.page-about .hist-hero {
  position: relative;
  padding: clamp(24px, 5vw, 44px) 0 clamp(44px, 7vw, 76px);
}

.page-about .hist-hero::before {
  content: "";
  position: absolute;
  top: -14%;
  right: -16%;
  width: min(720px, 82%);
  height: 92%;
  background: linear-gradient(126deg, rgba(47, 224, 224, 0.20) 0%, rgba(139, 92, 246, 0.26) 58%, rgba(139, 92, 246, 0) 100%);
  transform: skewY(-9deg);
  pointer-events: none;
  z-index: 0;
}

.page-about .hist-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 5vw, 44px);
  align-items: center;
}

@media (min-width: 920px) {
  .page-about .hist-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    gap: clamp(32px, 5vw, 64px);
  }

  .page-about .hist-hero__figure {
    transform: translateY(26px);
  }
}

.page-about .hist-hero h1 {
  margin: 14px 0 0;
  font-size: clamp(30px, 6.4vw, 52px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--c-paper);
}

.page-about .hist-hero__lede {
  margin: 18px 0 0;
  max-width: 44ch;
  font-size: clamp(17px, 2.4vw, 21px);
  line-height: 1.6;
  color: var(--c-paper);
}

.page-about .hist-hero__body {
  margin: 14px 0 0;
  max-width: 54ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--c-mist);
}

.page-about .hist-hero__cta {
  margin-top: 26px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

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

/* ---------- 年份跳转 ---------- */
.page-about .year-rail {
  border-top: 1px solid var(--c-steel);
  border-bottom: 1px solid var(--c-steel);
  background: var(--grad-band);
}

.page-about .year-rail__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
  padding-top: 14px;
  padding-bottom: 14px;
}

.page-about .year-rail__label {
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-mist);
}

.page-about .year-rail__link {
  display: inline-block;
  min-width: 72px;
  text-align: center;
  padding: 7px 12px;
  border: 1px solid var(--c-steel);
  background: rgba(6, 11, 24, 0.6);
  color: var(--c-paper);
  font-size: 14px;
  letter-spacing: 0.06em;
  text-decoration: none;
  transition: border-color 0.25s ease, color 0.25s ease, transform 0.25s ease;
}

.page-about .year-rail__link:hover,
.page-about .year-rail__link:focus-visible {
  border-color: var(--c-orange);
  color: var(--c-orange);
  transform: translateY(-2px);
}

/* ---------- 区块通用 ---------- */
.page-about .phase {
  padding-top: clamp(48px, 8vw, 84px);
  padding-bottom: clamp(48px, 8vw, 84px);
}

.page-about .phase--deep {
  background: var(--c-deep);
}

.page-about h2 {
  margin: 12px 0 0;
  font-size: clamp(24px, 4.2vw, 34px);
  line-height: 1.15;
  letter-spacing: -0.015em;
  font-weight: 800;
  color: var(--c-paper);
}

.page-about .phase__lede {
  margin: 16px 0 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--c-mist);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 38px 0 0;
  padding: 0;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: calc(var(--tl-rail) - 1px);
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-cyan) 0%, var(--c-violet) 46%, var(--c-orange) 100%);
  opacity: 0.55;
}

.page-about .tl-item {
  display: grid;
  grid-template-columns: var(--tl-gutter) minmax(0, 1fr);
  gap: 14px;
  padding-bottom: 28px;
}

.page-about .tl-item:last-child {
  padding-bottom: 0;
}

.page-about .tl-item--violet { --tl-accent: var(--c-violet); }
.page-about .tl-item--orange { --tl-accent: var(--c-orange); }
.page-about .tl-item--mint { --tl-accent: var(--c-mint); }

.page-about .tl-marker {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 9px;
  padding-top: 16px;
}

.page-about .tl-year {
  font-size: 11px;
  letter-spacing: 0.09em;
  color: var(--tl-accent);
}

.page-about .tl-dot {
  position: relative;
  z-index: 1;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--tl-accent);
  box-shadow: 0 0 0 5px var(--c-void), 0 0 0 6px var(--c-steel), 0 0 16px var(--tl-accent);
}

.page-about .phase--deep .tl-dot {
  box-shadow: 0 0 0 5px var(--c-deep), 0 0 0 6px var(--c-steel), 0 0 16px var(--tl-accent);
}

.page-about .tl-card {
  border: 1px solid var(--c-steel);
  border-left: 3px solid var(--tl-accent);
  background: linear-gradient(180deg, rgba(13, 23, 48, 0.94) 0%, rgba(6, 11, 24, 0.94) 100%);
  box-shadow: 6px 6px 0 0 rgba(16, 16, 20, 0.72);
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.page-about .tl-card:hover {
  border-color: var(--c-cyan);
  box-shadow: 6px 6px 0 0 rgba(47, 224, 224, 0.24);
}

.page-about .tl-item:target .tl-card {
  border-color: var(--c-orange);
  box-shadow: 6px 6px 0 0 rgba(255, 122, 47, 0.32);
}

.page-about .tl-card > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

.page-about .tl-card > summary::-webkit-details-marker {
  display: none;
}

.page-about .tl-card > summary::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1;
  color: var(--tl-accent);
}

.page-about .tl-card[open] > summary::after {
  content: "\2013";
}

.page-about .tl-title {
  margin: 0;
  font-size: clamp(18px, 2.5vw, 22px);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-paper);
}

.page-about .tl-body {
  padding: 0 18px 20px;
}

.page-about .tl-body p {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--c-mist);
}

.page-about .tl-points {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .tl-points li {
  position: relative;
  padding-left: 20px;
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--c-paper);
}

.page-about .tl-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 10px;
  height: 2px;
  background: var(--tl-accent);
}

/* ---------- 数据带 ---------- */
.page-about .stat-band {
  border-top: 1px solid var(--c-steel);
  border-bottom: 1px solid var(--c-steel);
}

.page-about .stat-band__inner {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--c-steel);
  padding: 0;
}

@media (min-width: 760px) {
  .page-about .stat-band__inner {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .stat-cell {
  background: var(--c-void);
  padding: 24px 18px;
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.6vw, 34px);
  line-height: 1.1;
  color: var(--c-cyan);
  letter-spacing: -0.01em;
}

.page-about .stat-label {
  display: block;
  margin-top: 8px;
  font-size: 13.5px;
  line-height: 1.5;
  color: var(--c-mist);
}

/* ---------- 团队 ---------- */
.page-about .team-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  align-items: center;
}

@media (min-width: 880px) {
  .page-about .team-head {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 46px;
  }
}

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

.page-about .quad {
  list-style: none;
  margin: 34px 0 0;
  padding: 0 0 18px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

@media (min-width: 700px) {
  .page-about .quad {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .quad-item:nth-child(2),
  .page-about .quad-item:nth-child(4) {
    transform: translateY(20px);
  }
}

.page-about .quad-item {
  --q: var(--c-cyan);
  position: relative;
  padding: 22px 22px 22px 26px;
  border: 1px solid var(--c-steel);
  background: rgba(13, 23, 48, 0.72);
}

.page-about .quad-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--q);
}

.page-about .quad-item--c { --q: var(--c-cyan); }
.page-about .quad-item--v { --q: var(--c-violet); }
.page-about .quad-item--o { --q: var(--c-orange); }
.page-about .quad-item--m { --q: var(--c-mint); }

.page-about .quad-item h3 {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 700;
  color: var(--c-paper);
}

.page-about .quad-item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--c-mist);
}

/* ---------- 流程 ---------- */
.page-about .flow {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
}

.page-about .flow-step {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 14px;
  padding: 22px 0;
  border-top: 1px solid var(--c-steel);
  transition: transform 0.25s ease, background-color 0.25s ease;
}

.page-about .flow-step:last-child {
  border-bottom: 1px solid var(--c-steel);
}

.page-about .flow-step:hover {
  transform: translateX(6px);
  background: rgba(47, 224, 224, 0.05);
}

.page-about .flow-num {
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1.6;
  color: var(--c-violet);
}

.page-about .flow-step h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--c-paper);
}

.page-about .flow-step p {
  margin: 0;
  max-width: 64ch;
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--c-mist);
}

.page-about .flow-out {
  display: inline-block;
  margin-top: 12px;
  padding: 4px 11px;
  border: 1px dashed var(--c-steel);
  font-size: 12px;
  letter-spacing: 0.02em;
  color: var(--c-mist);
  transition: border-color 0.25s ease, color 0.25s ease;
}

.page-about .flow-step:hover .flow-out {
  border-color: var(--c-cyan);
  color: var(--c-cyan);
}

.page-about .visual-strip {
  margin: clamp(30px, 5vw, 48px) 0 0;
  border: 1px solid var(--c-steel);
  background: var(--c-void);
}

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

.page-about .visual-strip figcaption {
  padding: 14px 18px;
  border-top: 1px solid var(--c-steel);
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-mist);
}

/* ---------- 协作 ---------- */
.page-about .panels {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 32px;
}

@media (min-width: 720px) {
  .page-about .panels {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .panel {
  padding: 24px 22px;
  border: 2px solid var(--c-steel);
  background: var(--c-deep);
  box-shadow: 8px 8px 0 0 rgba(139, 92, 246, 0.18);
}

.page-about .panel__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.8vw, 34px);
  line-height: 1.1;
  color: var(--c-cyan);
}

.page-about .panel p {
  margin: 12px 0 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--c-mist);
}

.page-about .partners-note {
  margin: 30px 0 0;
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--c-mist);
}

/* ---------- 下一步 ---------- */
.page-about .next-list {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

@media (min-width: 800px) {
  .page-about .next-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }
}

.page-about .next-item {
  display: block;
  height: 100%;
  padding: 24px 22px;
  border: 1px solid var(--c-steel);
  background: rgba(6, 11, 24, 0.62);
  text-decoration: none;
  transition: border-color 0.25s ease, transform 0.25s ease;
}

.page-about .next-item:hover,
.page-about .next-item:focus-visible {
  border-color: var(--c-orange);
  transform: translateY(-4px);
}

.page-about .next-item h3 {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 700;
  color: var(--c-paper);
}

.page-about .next-item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--c-mist);
}

.page-about .hist-cta {
  margin-top: clamp(34px, 5vw, 48px);
  padding: clamp(24px, 5vw, 38px);
  border: 2px solid var(--c-steel);
  background: linear-gradient(120deg, rgba(47, 224, 224, 0.10) 0%, rgba(139, 92, 246, 0.16) 100%);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.page-about .hist-cta p {
  margin: 0;
  font-size: clamp(18px, 2.8vw, 23px);
  line-height: 1.35;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-paper);
}

.page-about .hist-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}