.page-about {
  --about-text: 560px;
  display: block;
  padding: 0 20px 96px;
  background: var(--ink);
  color: var(--text);
  font-family: var(--font-body);
}

.page-about .about-wrap {
  max-width: 1200px;
  margin: 0 auto;
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 24px 0 0;
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  color: var(--muted);
}

.page-about .crumbs a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.26s var(--ease), border-color 0.26s var(--ease);
}

.page-about .crumbs a:hover,
.page-about .crumbs a:focus-visible {
  color: var(--turf);
  border-bottom-color: var(--turf);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  padding: 40px 0 56px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.24em;
  color: var(--turf);
  text-transform: uppercase;
}

.page-about .about-hero__title {
  margin: 16px 0 0;
  max-width: 16em;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(34px, 7.4vw, 78px);
  line-height: 1.06;
  letter-spacing: 0.02em;
  color: var(--white);
}

.page-about .about-hero__lede {
  margin: 24px 0 0;
  max-width: var(--about-text);
  font-size: var(--fs-18);
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-hero__aside {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 18px;
}

.page-about .about-hero__rot {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.32em;
  color: var(--muted);
}

.page-about .about-hero__vnote {
  font-size: var(--fs-12);
  letter-spacing: 0.18em;
  color: var(--muted);
}

/* ---------- 通用区块 ---------- */
.page-about .about-block {
  padding: 56px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-block:last-of-type {
  border-bottom: 0;
  padding-bottom: 40px;
}

.page-about .about-h2 {
  margin: 0 0 24px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(24px, 4vw, 34px);
  line-height: 1.22;
  letter-spacing: 0.02em;
  color: var(--white);
}

.page-about .about-origin__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.page-about .about-origin__body p {
  max-width: var(--about-text);
  margin: 0 0 20px;
  font-size: var(--fs-18);
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-origin__body p:last-child {
  margin-bottom: 0;
}

.page-about .about-origin__side {
  display: none;
}

.page-about .about-rot {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.3em;
  color: var(--muted);
  opacity: 0.65;
}

/* ---------- 赛季节点 ---------- */
.page-about .about-seasons__band {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
}

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

.page-about .about-tl__node {
  position: relative;
  padding: 0 0 36px 26px;
  border-left: 1px solid var(--line);
  transition: border-color 0.26s var(--ease);
}

.page-about .about-tl__node:last-child {
  border-left-color: transparent;
  padding-bottom: 0;
}

.page-about .about-tl__node:hover {
  border-left-color: var(--turf-soft);
}

.page-about .about-tl__dot {
  position: absolute;
  left: -4px;
  top: 7px;
  width: 7px;
  height: 7px;
  border: 1px solid var(--turf);
  border-radius: 50%;
  background: var(--ink);
  transition: background-color 0.26s var(--ease), transform 0.26s var(--ease);
}

.page-about .about-tl__node:hover .about-tl__dot,
.page-about .about-tl__node:focus-within .about-tl__dot {
  background: var(--turf);
  transform: scale(1.5);
}

.page-about .about-tl__tag {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.2em;
  color: var(--turf);
}

.page-about .about-tl__title {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: var(--fs-24);
  letter-spacing: 0.02em;
  color: var(--white);
}

.page-about .about-tl__desc {
  max-width: 520px;
  margin: 0 0 8px;
  font-size: var(--fs-18);
  line-height: 1.75;
  color: var(--text);
}

.page-about .about-tl__hint {
  max-width: 520px;
  margin: 0;
  padding-left: 0;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--muted);
  opacity: 0.55;
  transition: opacity 0.26s var(--ease), color 0.26s var(--ease);
}

.page-about .about-tl__node:hover .about-tl__hint,
.page-about .about-tl__node:focus-within .about-tl__hint {
  opacity: 1;
  color: var(--text);
}

.page-about .about-seasons__fig {
  margin: 0;
  max-width: 340px;
}

/* ---------- 复核流程 ---------- */
.page-about .about-check__lede {
  max-width: var(--about-text);
  margin: 0 0 32px;
  font-size: var(--fs-18);
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-tree {
  display: grid;
  grid-template-columns: 1fr;
  border: 1px solid var(--line);
}

.page-about .about-tree__step {
  padding: 28px 24px 32px;
  border-top: 1px solid var(--line);
  background: var(--rail);
}

.page-about .about-tree__step:first-child {
  border-top: 0;
}

.page-about .about-tree__idx {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: var(--fs-34);
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--offside);
}

.page-about .about-tree__title {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: var(--fs-24);
  letter-spacing: 0.02em;
  color: var(--white);
}

.page-about .about-tree__body {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .about-team__fig {
  margin: 0 0 32px;
}

.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-team__card {
  padding: 28px 24px 32px;
  background: var(--card);
}

.page-about .about-team__num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-52);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--turf);
}

.page-about .about-team__head {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: var(--fs-18);
  letter-spacing: 0.04em;
  color: var(--white);
}

.page-about .about-team__body {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 字段体系 ---------- */
.page-about .about-fields {
  position: relative;
  isolation: isolate;
}

.page-about .about-fields__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  opacity: 0.1;
  pointer-events: none;
}

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

.page-about .about-fields > *:not(.about-fields__bg) {
  position: relative;
  z-index: 1;
}

.page-about .about-fields__lede {
  max-width: var(--about-text);
  margin: 0 0 28px;
  font-size: var(--fs-18);
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-groups {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin: 0 0 36px;
  padding: 0;
}

.page-about .about-groups li {
  padding: 6px 14px;
  border: 1px solid var(--line);
  background: var(--card);
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.16em;
  color: var(--turf-soft);
}

.page-about .about-versions {
  display: grid;
  gap: 1px;
  max-width: 880px;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .about-ver {
  background: var(--ink);
}

.page-about .about-ver summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 20px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  letter-spacing: 0.12em;
  color: var(--text);
  transition: background-color 0.26s var(--ease), color 0.26s var(--ease);
}

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

.page-about .about-ver summary::after {
  content: "+";
  font-size: var(--fs-18);
  line-height: 1;
  color: var(--turf);
}

.page-about .about-ver[open] summary::after {
  content: "–";
}

.page-about .about-ver[open] summary {
  background: var(--card);
  color: var(--white);
}

.page-about .about-ver summary:focus-visible {
  outline: 2px solid var(--turf);
  outline-offset: -2px;
}

.page-about .about-ver p {
  max-width: 620px;
  margin: 0;
  padding: 16px 20px 22px;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 合作生态 ---------- */
.page-about .about-eco__lede {
  max-width: var(--about-text);
  margin: 0 0 32px;
  font-size: var(--fs-18);
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-eco__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .about-eco__item {
  padding: 28px 24px 32px;
  background: var(--rail);
}

.page-about .about-eco__num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-52);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--white);
}

.page-about .about-eco__head {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: var(--fs-18);
  letter-spacing: 0.04em;
  color: var(--turf);
}

.page-about .about-eco__body {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 三条准则 ---------- */
.page-about .about-rules__list {
  list-style: none;
  margin: 0 0 40px;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-rules__list li {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  padding: 26px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-rules__list h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: var(--fs-24);
  letter-spacing: 0.02em;
  color: var(--white);
}

.page-about .about-rules__list p {
  max-width: var(--about-text);
  margin: 0;
  font-size: var(--fs-18);
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

/* ---------- 平板 ---------- */
@media (min-width: 720px) {
  .page-about {
    padding: 0 40px 120px;
  }

  .page-about .about-block {
    padding: 72px 0;
  }

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

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

  .page-about .about-rules__list li {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 32px;
    align-items: start;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about {
    padding: 0 48px 140px;
  }

  .page-about .about-hero {
    grid-template-columns: minmax(0, 1fr) 220px;
    gap: 64px;
    align-items: end;
    padding: 88px 0 96px;
  }

  .page-about .about-hero__aside {
    align-items: flex-end;
    padding-bottom: 8px;
  }

  .page-about .about-hero__rot {
    transform: rotate(90deg);
    transform-origin: left center;
  }

  .page-about .about-origin__grid {
    grid-template-columns: minmax(0, 560px) minmax(0, 1fr);
    gap: 80px;
  }

  .page-about .about-origin__side {
    display: flex;
    justify-content: flex-end;
    align-items: flex-start;
    padding-top: 8px;
  }

  .page-about .about-seasons__band {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 72px;
    align-items: start;
  }

  .page-about .about-seasons__fig {
    position: sticky;
    top: 96px;
    max-width: none;
  }

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

  .page-about .about-tree__step {
    border-top: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-tree__step:first-child {
    border-left: 0;
  }

  .page-about .about-tree__step:nth-child(2) {
    padding-top: 52px;
  }

  .page-about .about-tree__step:nth-child(3) {
    padding-top: 78px;
  }
}

/* ---------- 宽松滚动偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl__node,
  .page-about .about-tl__dot,
  .page-about .about-tl__hint,
  .page-about .about-ver summary {
    transition: none;
  }
}