.page-about {
  --about-aside: 240px;
  display: block;
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  margin: 24px 0 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 30px 0 52px;
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -30% -10% auto -10%;
  height: 520px;
  background:
    radial-gradient(58% 78% at 16% 6%, rgba(53, 232, 224, 0.16), transparent 72%),
    radial-gradient(52% 72% at 90% 0%, rgba(164, 107, 255, 0.2), transparent 72%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 34px;
  grid-template-columns: minmax(0, 1fr);
}

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

.page-about .about-hero__lead h1 {
  margin: 18px 0 18px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 7.4vw, 58px);
  line-height: 1.16;
  letter-spacing: -0.015em;
  color: var(--text);
  text-shadow: 0 0 26px rgba(53, 232, 224, 0.28);
}

.page-about .about-hero__intro {
  margin: 0;
  max-width: 48ch;
  font-size: 16px;
  line-height: 1.9;
  color: var(--soft);
}

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

.page-about .about-hero__facts {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  align-content: start;
}

.page-about .about-hero__facts .metric {
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--r-card);
  background: linear-gradient(158deg, rgba(19, 28, 66, 0.92), rgba(11, 18, 48, 0.92));
}

.page-about .about-hero__facts .metric__value {
  color: var(--cyan);
  font-size: 24px;
  line-height: 1.2;
}

.page-about .about-hero__facts .metric__label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  color: var(--soft);
  line-height: 1.6;
}

/* ---------- 章节索引条 ---------- */
.page-about .about-toc {
  position: sticky;
  top: var(--topbar-h);
  z-index: 6;
  border-block: 1px solid var(--line);
  background: rgba(6, 10, 28, 0.9);
  backdrop-filter: blur(10px);
}

.page-about .about-toc__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 12px 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-toc__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-toc__list li {
  flex: 0 0 auto;
}

.page-about .about-toc__list a {
  display: inline-block;
  padding: 9px 16px;
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  font-size: 14px;
  line-height: 1.2;
  white-space: nowrap;
  color: var(--soft);
  text-decoration: none;
  transition: color 0.3s var(--ease), background 0.3s var(--ease), border-color 0.3s var(--ease);
}

.page-about .about-toc__list a:hover,
.page-about .about-toc__list a:focus-visible {
  color: var(--text);
  border-color: var(--violet);
  background: rgba(28, 42, 92, 0.6);
}

.page-about .about-toc__list a[aria-current="true"] {
  color: var(--abyss);
  background: var(--cyan);
  border-color: var(--cyan);
  font-weight: 600;
}

/* ---------- 章节骨架 ---------- */
.page-about .about-sec {
  padding: 54px 0;
  border-top: 1px solid var(--line);
}

.page-about .about-sec__grid {
  display: grid;
  gap: 28px;
  grid-template-columns: minmax(0, 1fr);
}

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

.page-about .about-sec__main h2 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 4.6vw, 36px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .about-sec__main p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--soft);
}

.page-about .about-kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.5;
  color: var(--gold);
}

.page-about .about-kicker::before {
  content: "";
  flex: 0 0 auto;
  width: 26px;
  height: 2px;
  border-radius: 2px;
  background: var(--gold);
}

.page-about .about-subhead {
  margin: 30px 0 0;
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
}

.page-about .about-figure {
  margin: 24px 0 28px;
}

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

.page-about .about-figure--honor {
  max-width: 520px;
}

.page-about .about-sec__aside {
  display: grid;
  gap: 14px;
  align-content: start;
  min-width: 0;
}

.page-about .aside-card {
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--violet);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  background: rgba(19, 28, 66, 0.55);
  font-size: 14px;
  line-height: 1.75;
  color: var(--soft);
}

.page-about .aside-card__k {
  display: block;
  margin-bottom: 6px;
  font-size: 22px;
  line-height: 1.2;
  color: var(--cyan);
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  margin: 8px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .timeline__item {
  --dot: var(--cyan);
  position: relative;
  padding: 0 0 30px 38px;
}

.page-about .timeline__item:nth-child(n + 4) {
  --dot: var(--violet);
}

.page-about .timeline__item:last-child {
  --dot: var(--gold);
  padding-bottom: 4px;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 22px;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--dot), transparent);
  opacity: 0.55;
}

.page-about .timeline__item:last-child::before {
  display: none;
}

.page-about .timeline__item::after {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--abyss);
  border: 2px solid var(--dot);
  box-shadow: 0 0 14px -2px var(--dot);
  transition: transform 0.35s var(--ease);
}

.page-about .timeline__item:hover::after {
  transform: scale(1.18);
}

.page-about .timeline__year {
  display: inline-block;
  margin-bottom: 6px;
  font-size: 14px;
  letter-spacing: 0.06em;
  color: var(--dot);
}

.page-about .timeline__item h3 {
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--text);
  transition: color 0.3s var(--ease);
}

.page-about .timeline__item:hover h3 {
  color: var(--dot);
}

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

/* ---------- 团队四宫格 ---------- */
.page-about .team-grid {
  display: grid;
  gap: 16px;
  grid-template-columns: minmax(0, 1fr);
  margin-top: 26px;
}

.page-about .team-card {
  position: relative;
  padding: 20px 20px 26px;
  background: linear-gradient(155deg, var(--surface), var(--night) 88%);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
  transition: transform 0.35s var(--ease), background 0.35s var(--ease);
}

.page-about .team-card:hover {
  transform: translateY(-4px);
  background: linear-gradient(155deg, var(--raised), var(--night) 88%);
}

.page-about .team-card__head {
  display: grid;
  gap: 6px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .team-card__head::after {
  content: "+";
  position: absolute;
  top: 16px;
  right: 18px;
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1;
  color: var(--soft);
}

.page-about .team-card[open] .team-card__head::after {
  content: "−";
  color: var(--cyan);
}

.page-about .team-card__idx {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.page-about .team-card__role {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text);
  padding-right: 24px;
}

.page-about .team-card__num {
  font-size: 13px;
  color: var(--cyan);
}

.page-about .team-card__body {
  padding-top: 14px;
}

.page-about .team-card__body ul {
  margin: 0;
  padding: 0 0 0 16px;
  list-style: none;
}

.page-about .team-card__body li {
  position: relative;
  padding-bottom: 9px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--soft);
}

.page-about .team-card__body li:last-child {
  padding-bottom: 0;
}

.page-about .team-card__body li::before {
  content: "";
  position: absolute;
  left: -13px;
  top: 10px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--violet);
}

/* ---------- 适配测试清单 ---------- */
.page-about .about-specs {
  display: grid;
  gap: 12px;
  grid-template-columns: minmax(0, 1fr);
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-specs li {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: rgba(11, 18, 48, 0.72);
}

.page-about .about-specs__k {
  display: block;
  margin-bottom: 6px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}

.page-about .about-specs__v {
  display: block;
  font-size: 14px;
  line-height: 1.75;
  color: var(--soft);
}

.page-about .about-steps {
  counter-reset: aboutstep;
  display: grid;
  gap: 10px;
  grid-template-columns: minmax(0, 1fr);
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-steps li {
  position: relative;
  padding: 16px 14px;
  border-radius: var(--r-sm);
  background: linear-gradient(160deg, rgba(28, 42, 92, 0.85), rgba(11, 18, 48, 0.85));
  font-size: 14px;
  line-height: 1.7;
  color: var(--soft);
}

.page-about .about-steps li::before {
  counter-increment: aboutstep;
  content: "0" counter(aboutstep);
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

/* ---------- 协作 ---------- */
.page-about .partner-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: minmax(0, 1fr);
  margin-top: 24px;
}

.page-about .partner-card h3 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--text);
}

.page-about .partner-card p {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--soft);
}

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

/* ---------- 收尾 ---------- */
.page-about .about-outro {
  position: relative;
  padding: 62px 0 84px;
  border-top: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-outro::before {
  content: "";
  position: absolute;
  inset: auto -12% -60% -12%;
  height: 420px;
  background:
    radial-gradient(48% 70% at 22% 60%, rgba(164, 107, 255, 0.18), transparent 72%),
    radial-gradient(44% 64% at 82% 70%, rgba(53, 232, 224, 0.14), transparent 72%);
  pointer-events: none;
}

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

.page-about .about-outro h2 {
  margin: 0 0 18px;
  max-width: 20ch;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 5vw, 42px);
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .about-outro p {
  margin: 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.95;
  color: var(--soft);
}

.page-about .about-outro__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about .about-hero {
    padding: 40px 0 64px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 0.85fr);
    align-items: end;
    gap: 52px;
  }

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

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

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

@media (min-width: 1000px) {
  .page-about .about-sec {
    padding: 68px 0;
  }

  .page-about .about-sec__grid {
    grid-template-columns: minmax(0, 1fr) var(--about-aside);
    gap: 56px;
  }

  .page-about .about-sec__aside {
    padding-top: 34px;
  }

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

@media (min-width: 1180px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .team-card {
    padding: 18px 16px 24px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .timeline__item::after,
  .page-about .timeline__item h3,
  .page-about .team-card,
  .page-about .about-toc__list a {
    transition: none;
  }

  .page-about .timeline__item:hover::after,
  .page-about .team-card:hover {
    transform: none;
  }
}