.page-about {
  --about-gap: 26px;
  --about-edge-cut: 18px;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: 22px;
}

.page-about .bk-crumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--c-muted);
}

.page-about .bk-crumbs a {
  color: var(--c-muted);
  text-decoration: none;
}

.page-about .bk-crumbs a:hover {
  color: var(--c-cyan);
}

.page-about .bk-crumbs li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--edge-strong);
}

.page-about .bk-crumbs [aria-current="page"] {
  color: var(--c-warm);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 22px 0 46px;
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -160px;
  right: -120px;
  width: 460px;
  height: 460px;
  background: radial-gradient(circle at center, rgba(35, 224, 200, 0.13), transparent 68%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 34px;
  position: relative;
}

.page-about .about-hero__title {
  margin: 12px 0 16px;
  font-size: clamp(30px, 6.6vw, 54px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  font-weight: 700;
  color: var(--c-warm);
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 56ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--c-muted);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin: 28px 0 0;
  padding: 18px 0 0;
  list-style: none;
  border-top: 1px solid var(--edge);
}

.page-about .about-hero__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 25px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--c-orange);
}

.page-about .about-hero__cap {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: 0.04em;
  color: var(--c-muted);
}

.page-about .about-hero__visual {
  position: relative;
  min-height: 236px;
  padding: 24px;
  display: flex;
  align-items: flex-end;
  border: 1px solid var(--edge);
  background: linear-gradient(158deg, var(--c-stand), var(--c-deep) 58%, var(--c-night));
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-edge-cut)), calc(100% - var(--about-edge-cut)) 100%, 0 100%);
  overflow: hidden;
}

.page-about .about-signal {
  position: absolute;
  top: 26px;
  left: 24px;
  right: 24px;
  height: 118px;
  display: flex;
  align-items: flex-end;
  gap: 8px;
}

.page-about .about-signal__bar {
  flex: 1 1 0;
  background: linear-gradient(180deg, var(--c-cyan), rgba(35, 224, 200, 0.05));
}

.page-about .about-signal__bar:nth-child(1) { height: 34%; }
.page-about .about-signal__bar:nth-child(2) { height: 62%; }
.page-about .about-signal__bar:nth-child(3) { height: 44%; }
.page-about .about-signal__bar:nth-child(4) { height: 90%; }
.page-about .about-signal__bar:nth-child(5) { height: 56%; }
.page-about .about-signal__bar:nth-child(6) { height: 76%; }
.page-about .about-signal__bar:nth-child(7) { height: 30%; }

.page-about .about-badge {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 14px;
  padding: 10px 18px;
  background: rgba(7, 11, 18, 0.78);
  border: 1px solid var(--orange-soft);
  clip-path: polygon(12px 0, 100% 0, 100% 100%, 0 100%, 0 12px);
}

.page-about .about-badge__tag {
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--c-orange);
}

.page-about .about-badge__score {
  font-family: var(--font-mono);
  font-size: 32px;
  font-weight: 700;
  line-height: 1;
  color: var(--c-warm);
}

/* ---------- 双栏骨架 ---------- */
.page-about .about-layout {
  display: grid;
  gap: 30px;
  padding-bottom: 56px;
}

.page-about .about-rail {
  min-width: 0;
}

.page-about .about-toc-list {
  display: flex;
  gap: 8px;
  margin: 10px 0 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-toc-list a {
  display: block;
  padding: 7px 13px;
  font-size: 13px;
  letter-spacing: 0.04em;
  white-space: nowrap;
  color: var(--c-muted);
  text-decoration: none;
  background: rgba(14, 23, 38, 0.7);
  border: 1px solid var(--edge-soft);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-toc-list a:hover {
  color: var(--c-warm);
  border-color: var(--edge-strong);
}

.page-about .about-toc-list a[aria-current="true"] {
  color: var(--c-night);
  background: var(--c-orange);
  border-color: var(--c-orange);
}

.page-about .about-flow {
  min-width: 0;
}

/* ---------- 章节面板 ---------- */
.page-about .about-sec {
  margin-bottom: 30px;
}

.page-about .about-sec__body {
  padding-top: 6px;
}

.page-about .about-sec__body > p {
  margin: 0;
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-muted);
}

.page-about .about-sec__body > p + p {
  margin-top: 16px;
}

.page-about .about-sec__body a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-soft);
}

.page-about .about-sec__body a:hover {
  color: var(--c-orange);
  border-bottom-color: var(--orange-soft);
}

.page-about .about-note {
  margin-top: 20px !important;
  padding-left: 14px;
  border-left: 2px solid var(--edge-strong);
  font-size: 14px !important;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 24px 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--edge-soft);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-edge-cut)), calc(100% - var(--about-edge-cut)) 100%, 0 100%);
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--c-muted);
}

.page-about .about-figure--tight {
  margin-top: 0;
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(132px, 1fr);
  gap: 0;
  margin: 28px 0 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-tl-item {
  position: relative;
  padding: 30px 14px 0 0;
}

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  top: 12px;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--edge);
}

.page-about .about-tl-dot {
  position: absolute;
  top: 6px;
  left: 0;
  width: 13px;
  height: 13px;
  background: var(--c-night);
  border: 1px solid var(--edge-strong);
  transform: rotate(45deg);
}

.page-about .about-tl-item:last-child .about-tl-dot {
  background: var(--c-orange);
  border-color: var(--c-orange);
  box-shadow: 0 0 0 5px rgba(255, 106, 26, 0.14);
}

.page-about .about-tl-year {
  display: block;
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--c-warm);
}

.page-about .about-tl-label {
  display: block;
  margin-top: 5px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--c-muted);
}

/* ---------- 阶段折叠 ---------- */
.page-about .about-stages {
  display: grid;
  gap: 10px;
  margin-top: 26px;
}

.page-about .about-stage {
  background: rgba(22, 34, 58, 0.42);
  border: 1px solid var(--edge-soft);
  border-left: 3px solid var(--c-line);
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 0 100%);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-stage[data-open="true"] {
  border-left-color: var(--c-cyan);
  background: rgba(22, 34, 58, 0.72);
}

.page-about .about-stage .bk-fold__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  width: 100%;
  margin: 0;
  padding: 14px 16px;
  background: transparent;
  border: 0;
  color: inherit;
  font: inherit;
  text-align: left;
  cursor: pointer;
}

.page-about .about-stage__year {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--c-orange);
}

.page-about .about-stage__title {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--c-warm);
}

.page-about .about-stage .bk-fold__body {
  padding: 0 16px 16px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-muted);
}

.page-about .about-stage .bk-fold__body p {
  margin: 0;
  max-width: 66ch;
}

/* ---------- 三段流程 ---------- */
.page-about .about-steps {
  display: grid;
  gap: 14px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-step {
  padding: 18px 18px 20px;
  background: rgba(14, 23, 38, 0.72);
  border: 1px solid var(--edge-soft);
  border-top: 2px solid var(--c-cyan);
}

.page-about .about-step__idx {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--c-cyan);
}

.page-about .about-step .bk-h3 {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--c-warm);
}

.page-about .about-step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-muted);
}

/* ---------- 团队卡片 ---------- */
.page-about .about-crew {
  display: grid;
  gap: 16px;
  margin-top: 26px;
}

.page-about .about-crew__card {
  padding: 20px 18px 22px;
  background: linear-gradient(180deg, var(--c-panel), rgba(14, 23, 38, 0.9));
  border: 1px solid var(--edge-soft);
  clip-path: polygon(0 0, calc(100% - var(--about-edge-cut)) 0, 100% var(--about-edge-cut), 100% 100%, 0 100%);
}

.page-about .about-crew__role {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-cyan);
}

.page-about .about-crew__n {
  margin: 10px 0 4px;
  font-family: var(--font-mono);
  font-size: 46px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--c-orange);
}

.page-about .about-crew__card .bk-h3 {
  margin: 10px 0 10px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--c-warm);
}

.page-about .about-crew__card p:last-child {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-muted);
}

/* ---------- 规模数字带 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 26px;
  background: var(--edge-soft);
  border: 1px solid var(--edge-soft);
}

.page-about .about-stat {
  padding: 20px 16px;
  background: var(--c-night);
}

.page-about .about-stat__n {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--c-warm);
}

.page-about .about-stat__n em {
  margin-left: 4px;
  font-family: var(--font-body);
  font-style: normal;
  font-size: 13px;
  font-weight: 500;
  color: var(--c-cyan);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-muted);
}

/* ---------- 吉林区 ---------- */
.page-about .about-jilin {
  display: grid;
  gap: 22px;
  margin-top: 22px;
}

.page-about .about-jilin__copy p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-muted);
}

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

/* ---------- 栏目说明 ---------- */
.page-about .about-cols {
  display: grid;
  gap: 14px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-col {
  padding: 16px 16px 18px;
  background: rgba(14, 23, 38, 0.6);
  border: 1px solid var(--edge-soft);
  border-left: 3px solid var(--c-orange);
}

.page-about .about-col .bk-h3 {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--c-warm);
}

.page-about .about-col p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-muted);
}

/* ---------- 收尾 ---------- */
.page-about .about-signoff {
  position: relative;
  margin-top: 8px;
  padding: 28px 22px 26px;
  background: linear-gradient(140deg, var(--c-stand), var(--c-deep) 70%, var(--c-night));
  border: 1px solid var(--edge);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

.page-about .about-signoff .bk-h2 {
  margin: 0 0 12px;
}

.page-about .about-signoff p {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-muted);
}

.page-about .about-signoff p a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-soft);
}

.page-about .about-signoff p a:hover {
  color: var(--c-orange);
  border-bottom-color: var(--orange-soft);
}

.page-about .about-signoff__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.page-about .about-topline {
  display: flex;
  justify-content: flex-end;
  margin-top: 26px;
}

.page-about .bk-to-top {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--c-muted);
  text-decoration: none;
}

.page-about .bk-to-top:hover {
  color: var(--c-cyan);
}

.page-about .bk-to-top-arrow {
  font-family: var(--font-mono);
  color: var(--c-orange);
}

/* ---------- 桌面布局 ---------- */
@media (min-width: 768px) {
  .page-about .about-hero {
    padding: 32px 0 60px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: 7fr 5fr;
    align-items: center;
    gap: 44px;
  }

  .page-about .about-hero__visual {
    min-height: 300px;
  }

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

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

  .page-about .about-crew__card:nth-child(2) {
    margin-top: 24px;
  }

  .page-about .about-crew__card:nth-child(3) {
    margin-top: 48px;
  }

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

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

  .page-about .about-step:nth-child(2) {
    margin-top: 16px;
  }

  .page-about .about-step:nth-child(3) {
    margin-top: 32px;
  }

  .page-about .about-jilin {
    grid-template-columns: 5fr 7fr;
    align-items: center;
    gap: 28px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: 224px minmax(0, 1fr);
    gap: 52px;
    align-items: start;
    padding-bottom: 76px;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--quickbar-h) + 24px);
  }

  .page-about .about-toc-list {
    flex-direction: column;
    gap: 0;
    margin-top: 14px;
    padding: 0;
    overflow: visible;
    border-left: 1px solid var(--edge);
  }

  .page-about .about-toc-list a {
    padding: 9px 12px;
    margin-left: -1px;
    white-space: normal;
    background: transparent;
    border: 0;
    border-left: 2px solid transparent;
  }

  .page-about .about-toc-list a[aria-current="true"] {
    color: var(--c-orange);
    background: transparent;
    border-left-color: var(--c-orange);
  }

  .page-about .about-toc-list a:hover {
    background: rgba(22, 34, 58, 0.55);
  }

  .page-about .about-sec {
    margin-bottom: 38px;
  }

  .page-about .about-hero__title {
    font-size: clamp(38px, 4.2vw, 54px);
  }

  .page-about .about-stat__n {
    font-size: 34px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc-list a,
  .page-about .about-stage {
    transition: none;
  }
}