.page-about {
  --about-radius: var(--radius-lg);
  display: block;
  padding-bottom: 72px;
  font-family: var(--font-body);
  color: var(--text);
  background: var(--ink-900);
}

/* ---------- 首屏 ---------- */
.page-about .about-cover {
  position: relative;
  padding: 20px 0 8px;
  overflow: hidden;
  background:
    radial-gradient(130% 92% at 6% -20%, rgba(28, 107, 74, .52), transparent 62%),
    radial-gradient(88% 68% at 98% 0%, rgba(47, 169, 201, .22), transparent 66%),
    linear-gradient(180deg, var(--ink-900) 0%, var(--field) 70%, var(--ink-900) 100%);
}

.page-about .about-cover::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(115deg, rgba(237, 242, 247, .035) 0 1px, transparent 1px 9px);
}

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

.page-about .about-cover__grid {
  display: grid;
  gap: 26px;
  margin-top: 24px;
}

.page-about .about-cover__lead h1 {
  margin: 10px 0 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(30px, 8.2vw, 56px);
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--text);
}

.page-about .about-cover__lede {
  margin: 16px 0 0;
  max-width: 46ch;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(237, 242, 247, .82);
}

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

.page-about .about-figure {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background: linear-gradient(155deg, var(--ink-700), var(--field) 72%);
  box-shadow: var(--shadow-panel);
  aspect-ratio: var(--ar, 16 / 9);
}

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

.page-about .about-figure__cap {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  padding: 26px 18px 13px;
  font-size: 12.5px;
  line-height: 1.6;
  color: rgba(237, 242, 247, .74);
  background: linear-gradient(to top, rgba(10, 22, 38, .94), rgba(10, 22, 38, 0));
}

.page-about .about-figure--cover { --ar: 7 / 4; }
.page-about .about-figure--team { --ar: 3 / 2; margin-top: 30px; }
.page-about .about-figure--flow { --ar: 3 / 2; }

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 18px;
  margin: 32px 0 0;
  padding: 24px 0 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

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

.page-about .about-facts__num {
  font-family: var(--font-num);
  font-weight: 600;
  font-size: 26px;
  line-height: 1.1;
  color: var(--accent);
}

.page-about .about-facts__label {
  font-size: 13px;
  line-height: 1.55;
  color: var(--muted);
}

/* ---------- 章节通用 ---------- */
.page-about .about-chapter {
  padding-top: 52px;
}

.page-about .about-chapter__wrap {
  position: relative;
  padding: 30px 20px 34px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background:
    linear-gradient(158deg, rgba(27, 42, 71, .74), rgba(18, 33, 54, .92) 64%),
    var(--ink-800);
  box-shadow: var(--shadow-panel);
}

.page-about .about-chapter__num {
  position: absolute;
  top: -26px;
  right: 8px;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: 118px;
  line-height: 1;
  letter-spacing: -.06em;
  color: rgba(57, 255, 158, .12);
  pointer-events: none;
  user-select: none;
}

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

.page-about .about-chapter__head .section-head__title {
  margin: 8px 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(22px, 5.6vw, 34px);
  line-height: 1.28;
  letter-spacing: -.01em;
}

.page-about .about-chapter__head .section-head__note {
  margin: 12px 0 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-chapter__prose p {
  margin: 0 0 1.15em;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(237, 242, 247, .86);
}

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

.page-about .about-cols {
  display: grid;
  gap: 26px;
  margin-top: 26px;
}

/* ---------- 侧栏数据卡 ---------- */
.page-about .about-sidecard {
  padding: 22px 20px 24px;
  border-radius: var(--radius-md);
}

.page-about .about-sidecard .eyebrow {
  margin: 0 0 14px;
}

.page-about .about-issues {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-issues li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(237, 242, 247, .8);
}

.page-about .about-issues li::before {
  content: "";
  position: absolute;
  top: 9px;
  left: 0;
  width: 8px;
  height: 2px;
  background: var(--accent-2);
}

/* ---------- 团队三角 ---------- */
.page-about .about-triad {
  position: relative;
  display: grid;
  gap: 16px;
  margin-top: 30px;
}

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

.page-about .about-triad__node {
  position: relative;
  padding: 20px 18px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(160deg, rgba(10, 22, 38, .82), rgba(18, 33, 54, .7));
  transition: transform .28s var(--ease), border-color .28s var(--ease), box-shadow .28s var(--ease);
}

.page-about .about-triad__node::before {
  content: "";
  position: absolute;
  top: 0;
  left: 18px;
  width: 34px;
  height: 3px;
  border-radius: 0 0 3px 3px;
  background: var(--accent);
}

.page-about .about-triad__node--perf::before { background: var(--teal); }
.page-about .about-triad__node--support::before { background: var(--accent-2); }

.page-about .about-triad__node .eyebrow {
  margin: 0;
  font-size: 12px;
}

.page-about .about-triad__size {
  margin: 10px 0 8px;
  font-family: var(--font-num);
  font-weight: 600;
  font-size: 24px;
  line-height: 1;
  color: var(--text);
}

.page-about .about-triad__size .u-mono {
  font-size: 30px;
}

.page-about .about-triad__node--edit .about-triad__size .u-mono { color: var(--accent); }
.page-about .about-triad__node--perf .about-triad__size .u-mono { color: var(--teal); }
.page-about .about-triad__node--support .about-triad__size .u-mono { color: var(--accent-2); }

.page-about .about-triad__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: rgba(237, 242, 247, .76);
}

.page-about .about-triad__node:hover,
.page-about .about-triad__node:focus-within {
  transform: translateY(-6px);
  border-color: var(--line-strong);
  box-shadow: 0 20px 44px rgba(4, 10, 20, .5);
}

/* ---------- 生产流程 ---------- */
.page-about .about-flow {
  position: relative;
  margin: 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.page-about .about-flow::before {
  content: "";
  position: absolute;
  top: 8px;
  bottom: 10px;
  left: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--accent), var(--teal) 55%, rgba(47, 169, 201, 0));
}

.page-about .about-flow__step {
  position: relative;
  display: block;
  padding-bottom: 22px;
}

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

.page-about .about-flow__step::before {
  content: "";
  position: absolute;
  top: 6px;
  left: -22px;
  width: 9px;
  height: 9px;
  border: 2px solid var(--accent);
  border-radius: 50%;
  background: var(--ink-900);
  box-shadow: 0 0 0 4px rgba(57, 255, 158, .12);
}

.page-about .about-flow__step:nth-child(4)::before {
  border-color: var(--warn);
  box-shadow: 0 0 0 4px rgba(255, 209, 102, .14);
}

.page-about .about-flow__step:last-child::before {
  border-color: var(--accent-2);
  box-shadow: 0 0 0 4px rgba(255, 138, 61, .14);
}

.page-about .about-flow__time {
  display: block;
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--accent-2);
}

.page-about .about-flow__title {
  display: block;
  margin-top: 5px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 16.5px;
  line-height: 1.45;
  color: var(--text);
}

.page-about .about-flow__desc {
  display: block;
  margin-top: 4px;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(237, 242, 247, .7);
}

/* ---------- 线路节点 ---------- */
.page-about .about-network {
  display: grid;
  gap: 26px;
  margin-top: 26px;
}

.page-about .about-network__text p {
  margin: 0 0 1.15em;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(237, 242, 247, .86);
}

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

.page-about .about-nodes {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-nodes__item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 16px 14px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(165deg, rgba(47, 169, 201, .1), rgba(10, 22, 38, .74));
}

.page-about .about-nodes__region {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .04em;
  color: var(--text);
}

.page-about .about-nodes__dots {
  display: flex;
  gap: 5px;
}

.page-about .about-nodes__dots i {
  display: block;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 10px rgba(57, 255, 158, .45);
}

.page-about .about-nodes__note {
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  margin-top: 30px;
  padding-left: 18px;
  border-left: 1px solid var(--line-strong);
}

.page-about .about-timeline__item {
  margin: 0 0 12px;
  padding-left: 16px;
  border: 0;
  border-left: 2px solid transparent;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  transition: border-color .26s var(--ease), background-color .26s var(--ease);
}

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

.page-about .about-timeline__item[open] {
  border-left-color: var(--accent);
  background: rgba(57, 255, 158, .05);
}

.page-about .about-timeline__head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 12px 12px 12px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-timeline__dot {
  flex: none;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--muted);
  transition: background-color .26s var(--ease), box-shadow .26s var(--ease);
}

.page-about .about-timeline__item[open] .about-timeline__dot {
  background: var(--accent);
  box-shadow: 0 0 0 4px rgba(57, 255, 158, .16);
}

.page-about .about-timeline__year {
  flex: none;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .02em;
  color: var(--accent-2);
}

.page-about .about-timeline__label {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 15.5px;
  line-height: 1.5;
  color: var(--text);
}

.page-about .about-timeline__body {
  padding: 0 12px 16px 30px;
}

.page-about .about-timeline__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(237, 242, 247, .74);
}

/* ---------- 固定做法 ---------- */
.page-about .about-practice {
  display: grid;
  gap: 14px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-practice__item {
  position: relative;
  padding: 16px 18px 18px 54px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(160deg, rgba(27, 42, 71, .5), rgba(10, 22, 38, .62));
}

.page-about .about-practice__idx {
  position: absolute;
  top: 17px;
  left: 16px;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
}

.page-about .about-practice__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(237, 242, 247, .82);
}

/* ---------- 合作 ---------- */
.page-about .about-partner {
  display: grid;
  gap: 24px;
  margin-top: 28px;
}

.page-about .about-partner__folds {
  display: grid;
  gap: 10px;
  align-content: start;
}

.page-about .about-partner__fold {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(10, 22, 38, .55);
  transition: border-color .26s var(--ease);
}

.page-about .about-partner__fold[open] {
  border-color: rgba(57, 255, 158, .34);
  background: rgba(57, 255, 158, .05);
}

.page-about .about-partner__q {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 15px;
  line-height: 1.5;
  color: var(--text);
}

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

.page-about .about-partner__icon {
  position: relative;
  flex: none;
  width: 14px;
  height: 14px;
}

.page-about .about-partner__icon::before,
.page-about .about-partner__icon::after {
  content: "";
  position: absolute;
  background: var(--accent);
  transition: transform .26s var(--ease);
}

.page-about .about-partner__icon::before {
  top: 6px;
  left: 0;
  width: 14px;
  height: 2px;
}

.page-about .about-partner__icon::after {
  top: 0;
  left: 6px;
  width: 2px;
  height: 14px;
}

.page-about .about-partner__fold[open] .about-partner__icon::after {
  transform: scaleY(0);
}

.page-about .about-partner__a {
  padding: 0 16px 16px 42px;
}

.page-about .about-partner__a p {
  margin: 0;
  font-size: 14px;
  line-height: 1.82;
  color: rgba(237, 242, 247, .78);
}

.page-about .about-partner__a a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid rgba(57, 255, 158, .4);
}

.page-about .about-partner__a a:hover,
.page-about .about-partner__a a:focus-visible {
  color: var(--warn);
  border-bottom-color: rgba(255, 209, 102, .5);
}

.page-about .about-sidecard--close {
  border-color: rgba(255, 138, 61, .24);
  background: linear-gradient(158deg, rgba(255, 138, 61, .1), rgba(18, 33, 54, .86));
}

.page-about .about-sidecard__lead {
  margin: 0 0 16px;
  font-size: 14.5px;
  line-height: 1.82;
  color: rgba(237, 242, 247, .82);
}

.page-about .about-sidecard__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 20px;
  margin: 0;
}

.page-about .about-sidecard__links .link-arrow {
  font-size: 14px;
  font-weight: 600;
}

/* ---------- 平板 ---------- */
@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px 24px;
  }

  .page-about .about-chapter {
    padding-top: 66px;
  }

  .page-about .about-chapter__wrap {
    padding: 38px 32px 42px;
  }

  .page-about .about-chapter__num {
    font-size: 150px;
  }

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

  .page-about .about-nodes {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 980px) {
  .page-about .about-cover {
    padding: 28px 0 16px;
  }

  .page-about .about-cover__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.08fr);
    align-items: end;
    gap: 48px;
    margin-top: 34px;
  }

  .page-about .about-cols {
    grid-template-columns: minmax(0, 1.62fr) minmax(0, 1fr);
    gap: 42px;
    align-items: start;
  }

  .page-about .about-cols--flow {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    align-items: center;
  }

  .page-about .about-network {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
    gap: 44px;
    align-items: center;
  }

  .page-about .about-partner {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-chapter {
    padding-top: 84px;
  }

  .page-about .about-chapter__wrap {
    padding: 48px 52px 52px;
  }

  .page-about .about-chapter--alt .about-chapter__wrap {
    margin-left: clamp(24px, 5vw, 80px);
  }

  .page-about .about-chapter:not(.about-chapter--alt) .about-chapter__wrap {
    margin-right: clamp(24px, 5vw, 80px);
  }

  .page-about .about-triad {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
    margin-top: 42px;
    padding-top: 22px;
  }

  .page-about .about-triad__lines {
    display: block;
    position: absolute;
    top: 0;
    left: 4%;
    width: 92%;
    height: 100%;
    pointer-events: none;
  }

  .page-about .about-triad__node {
    z-index: 1;
  }

  .page-about .about-figure--team {
    margin-top: 44px;
  }

  .page-about .about-timeline {
    padding-left: 24px;
  }

  .page-about .about-timeline__head {
    padding: 14px 16px 14px 0;
    gap: 16px;
  }

  .page-about .about-timeline__label {
    font-size: 16.5px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-cover__grid {
    gap: 60px;
  }

  .page-about .about-chapter__num {
    font-size: 172px;
    top: -34px;
    right: 26px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-triad__node,
  .page-about .about-timeline__dot,
  .page-about .about-partner__icon::after,
  .page-about .about-partner__fold {
    transition: none;
  }

  .page-about .about-triad__node:hover,
  .page-about .about-triad__node:focus-within {
    transform: none;
  }
}