.page-about {
  --ab-rail: 66px;
  --ab-cut: 16px;
  background: var(--ink);
  color: var(--paper);
  overflow-x: hidden;
}

.page-about .about-progress {
  position: fixed;
  inset: 0 0 auto 0;
  height: 2px;
  background: linear-gradient(90deg, var(--lime), var(--orange));
  transform: scaleX(0);
  transform-origin: 0 50%;
  z-index: 30;
  pointer-events: none;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 104px 0 48px;
  background: var(--ink);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -36%;
  width: 118%;
  height: 165%;
  background: var(--panel);
  transform: rotate(14deg);
  border-left: 1px solid var(--lime-line);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 46%;
  height: 3px;
  background: linear-gradient(90deg, var(--lime), transparent);
}

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

.page-about .about-hero .breadcrumbs {
  margin-bottom: 28px;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 8.6vw, 84px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  margin: 12px 0 20px;
  max-width: 15em;
}

.page-about .about-hero__lead {
  max-width: 38em;
  font-size: 15px;
  line-height: 1.75;
  color: var(--paper);
  margin: 0 0 36px;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 20px 0;
}

.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 8vw, 68px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--lime);
}

.page-about .about-hero__unit {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--orange);
}

.page-about .about-hero__label {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .about-hero__meta {
  margin: 20px 0 0;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* ---------- 锚点目录 ---------- */
.page-about .about-toc-section {
  padding: 0 0 12px;
}

.page-about .about-toc > summary {
  cursor: pointer;
  list-style: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  font-size: 13px;
  color: var(--paper);
  background: var(--panel);
}

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

.page-about .about-toc > summary::after {
  content: "▾";
  color: var(--lime);
  font-size: 11px;
}

.page-about .about-toc > .about-toc__list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 20px;
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
}

.page-about .about-toc__list a {
  display: inline-block;
  padding: 6px 0;
  font-size: 13px;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .about-toc__list a:hover,
.page-about .about-toc__list a:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime-line);
}

/* ---------- 赛季时间轴 ---------- */
.page-about .about-seasons__figure {
  margin: 0 0 40px;
}

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

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 18px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--lime) 0%, var(--orange) 55%, var(--line) 100%);
  opacity: 0.7;
}

.page-about .tl-node {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 2px;
  clip-path: polygon(0 0, calc(100% - var(--ab-cut)) 0, 100% var(--ab-cut), 100% 100%, var(--ab-cut) 100%, 0 calc(100% - var(--ab-cut)));
  padding: 20px 20px 18px;
  margin-bottom: 22px;
  transition: transform 240ms var(--ease), border-color 240ms var(--ease);
}

.page-about .tl-node:hover {
  border-color: var(--lime-line);
  transform: translateX(2px);
}

.page-about .tl-node__dot {
  position: absolute;
  left: calc(12px - var(--ab-rail));
  top: 24px;
  width: 12px;
  height: 12px;
  background: var(--orange);
  transform: rotate(45deg);
  box-shadow: 0 0 0 4px var(--ink);
}

.page-about .tl-node__year {
  font-family: var(--font-mono);
  font-size: clamp(30px, 9vw, 58px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--lime);
  margin: 0 0 10px;
}

.page-about .tl-node__title {
  font-size: 17px;
  font-weight: 700;
  line-height: 1.5;
  margin: 0 0 8px;
}

.page-about .tl-node__desc {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  margin: 0 0 14px;
}

.page-about .tl-node__more summary {
  cursor: pointer;
  list-style: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--orange);
  padding: 4px 0;
}

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

.page-about .tl-node__more summary::before {
  content: "+";
  font-family: var(--font-mono);
  font-size: 14px;
}

.page-about .tl-node__more[open] summary::before {
  content: "−";
}

.page-about .tl-node__more p {
  margin: 10px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 13px;
  line-height: 1.75;
  color: var(--paper);
}

/* ---------- 数据流程 ---------- */
.page-about .about-flow__grid {
  align-items: start;
  row-gap: 36px;
}

.page-about .about-flow__list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-flow__item {
  border-left: 2px solid var(--line);
  padding-left: 16px;
  transition: border-color 220ms var(--ease);
}

.page-about .about-flow__item:hover {
  border-left-color: var(--lime);
}

.page-about .about-flow__step {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .about-flow__item h3 {
  font-size: 16px;
  font-weight: 700;
  margin: 6px 0 6px;
}

.page-about .about-flow__item p {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  margin: 0;
}

.page-about .about-flow__figure {
  margin: 0 0 20px;
}

.page-about .about-flow__timing {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.page-about .about-flow__timing-item {
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 2px solid var(--lime);
  padding: 14px 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-flow__timing-num {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-flow__timing-unit {
  font-size: 12px;
  color: var(--orange);
}

.page-about .about-flow__timing-label {
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .about-team__grid {
  row-gap: 16px;
}

.page-about .about-team__card {
  padding: 22px 20px;
}

.page-about .about-team__count {
  display: block;
  font-family: var(--font-mono);
  font-size: 46px;
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
  margin-bottom: 12px;
}

.page-about .about-team__role {
  font-size: 16px;
  font-weight: 700;
  margin: 0 0 8px;
  color: var(--lime);
}

.page-about .about-team__duty {
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
  margin: 0;
  transition: color 220ms var(--ease);
}

.page-about .about-team__card:hover .about-team__duty {
  color: var(--paper);
}

/* ---------- 供稿伙伴 ---------- */
.page-about .about-partners__grid {
  row-gap: 32px;
  align-items: center;
}

.page-about .about-partners__note {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.75;
  margin: 0 0 24px;
}

.page-about .about-partners__split {
  display: grid;
  gap: 16px;
  grid-template-columns: 1fr;
}

.page-about .about-partners__block {
  padding: 24px 20px;
  border-left: 3px solid var(--lime);
}

.page-about .about-partners__block--orange {
  border-left-color: var(--orange);
  margin-left: 0;
}

.page-about .about-partners__num {
  font-family: var(--font-mono);
  font-size: 54px;
  font-weight: 700;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-partners__block--orange .about-partners__num {
  color: var(--orange);
}

.page-about .about-partners__unit {
  font-size: 13px;
  color: var(--muted);
  margin-left: 6px;
}

.page-about .about-partners__name {
  font-size: 16px;
  font-weight: 700;
  margin: 12px 0 6px;
}

.page-about .about-partners__block p {
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
  margin: 0;
}

/* ---------- 白皮书 ---------- */
.page-about .about-whitepaper__grid {
  row-gap: 32px;
  align-items: start;
}

.page-about .about-whitepaper__list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-whitepaper__list li {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-whitepaper__k {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  color: var(--orange);
  min-width: 4.5em;
}

.page-about .about-whitepaper__v {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
}

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

/* ---------- 接下来 ---------- */
.page-about .about-roadmap__panel {
  padding: 30px 22px;
  border-top: 2px solid var(--lime);
}

.page-about .about-roadmap__lead p.section__desc {
  max-width: 40em;
}

.page-about .about-roadmap__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .about-roadmap__list {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-roadmap__list li {
  display: grid;
  gap: 8px;
  padding: 16px 0 0;
  border-top: 1px dashed var(--line);
}

.page-about .about-roadmap__list p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-roadmap__tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--lime);
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero {
    padding: 128px 0 64px;
  }

  .page-about .about-hero__lead {
    font-size: 17px;
  }

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

  .page-about .about-partners__block--orange {
    margin-top: 32px;
  }

  .page-about .about-whitepaper__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 28px;
  }

  .page-about .about-roadmap__panel {
    padding: 44px 34px;
  }

  .page-about .about-roadmap__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-roadmap__list li {
    padding-top: 18px;
  }
}

@media (min-width: 900px) {
  .page-about {
    --ab-rail: 128px;
    --ab-cut: 22px;
  }

  .page-about .about-hero {
    padding: 148px 0 80px;
  }

  .page-about .about-hero::before {
    top: -40%;
    right: -18%;
    width: 72%;
    height: 180%;
  }

  .page-about .about-hero__meta {
    font-size: 13px;
  }

  .page-about .about-toc > summary {
    display: none;
  }

  .page-about .about-toc > .about-toc__list {
    display: flex !important;
    gap: 28px;
    margin-top: 0;
  }

  .page-about .tl-node {
    padding: 26px 28px 22px;
  }

  .page-about .tl-node:nth-child(3n + 1) {
    max-width: calc(100% - 8px);
  }

  .page-about .tl-node:nth-child(3n + 2) {
    max-width: 82%;
    margin-left: 6%;
  }

  .page-about .tl-node:nth-child(3n + 3) {
    max-width: 90%;
    margin-left: 2%;
  }

  .page-about .about-team__count {
    font-size: 56px;
  }

  .page-about .about-whitepaper__grid {
    align-items: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-node,
  .page-about .about-team__duty,
  .page-about .about-toc__list a {
    transition: none;
  }

  .page-about .tl-node:hover {
    transform: none;
  }
}