.page-about {
  display: block;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(24px, 4.5vw, 60px) 0 clamp(34px, 5.5vw, 72px);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--line) 22%, var(--line) 78%, transparent);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
  align-items: start;
}

.page-about .about-hero__text h1 {
  margin: 14px 0 18px;
  font-family: var(--font-heading);
  font-size: clamp(1.85rem, 4.4vw, 3.35rem);
  line-height: 1.2;
  letter-spacing: .012em;
  color: var(--paper);
}

.page-about .about-hero__text .lede {
  max-width: 56ch;
  color: var(--muted);
}

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

.page-about .about-hero__panel {
  position: relative;
  padding: 22px 22px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background:
    radial-gradient(120% 92% at 78% 0%, var(--cyan-12), transparent 62%),
    var(--ink-800);
  box-shadow: var(--shadow-card);
}

.page-about .about-hero__svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-hero__metrics {
  list-style: none;
  margin: 14px 0 0;
  padding: 16px 0 0;
  border-top: 1px solid var(--line-soft);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 18px;
}

.page-about .metric__value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.15rem, 2.4vw, 1.4rem);
  letter-spacing: .02em;
  color: var(--cyan);
}

.page-about .metric__label {
  display: block;
  margin-top: 5px;
  font-size: .75rem;
  letter-spacing: .05em;
  color: var(--muted);
}

@media (min-width: 980px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 76px);
  }
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
}

.page-about .about-timeline__figure {
  margin: clamp(24px, 3vw, 38px) 0 0;
  aspect-ratio: 3 / 2;
}

.page-about .about-timeline__rail {
  position: relative;
  list-style: none;
  margin: clamp(30px, 4vw, 48px) 0 0;
  padding: 0 0 0 28px;
}

.page-about .about-timeline__rail::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan-40), var(--line-soft) 24%, var(--line-soft) 80%, transparent);
}

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

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

.page-about .tl-item::after {
  content: "";
  position: absolute;
  left: -27px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  border: 1px solid var(--cyan);
  background: var(--ink-900);
}

.page-about .tl-item__num {
  display: block;
  margin: 0;
  font-size: .8rem;
  letter-spacing: .16em;
  color: var(--cyan);
}

.page-about .tl-item__title {
  margin: 6px 0 8px;
  font-family: var(--font-heading);
  font-size: clamp(1.05rem, 2vw, 1.2rem);
  line-height: 1.4;
  color: var(--paper);
}

.page-about .tl-item__text {
  margin: 0;
  max-width: 64ch;
  font-size: .95rem;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .tl-item__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
}

@media (min-width: 900px) {
  .page-about .about-timeline__rail {
    padding-left: 0;
  }

  .page-about .about-timeline__rail::before {
    left: 118px;
  }

  .page-about .tl-item {
    display: grid;
    grid-template-columns: 96px minmax(0, 1fr);
    column-gap: 46px;
    padding-bottom: 38px;
  }

  .page-about .tl-item::after {
    left: 118px;
    top: 9px;
    transform: translateX(-50%);
  }

  .page-about .tl-item__num {
    padding-top: 2px;
    text-align: right;
    font-size: .88rem;
  }

  .page-about .tl-item__title {
    margin-top: 0;
  }
}

/* ---------- 目录树 ---------- */
.page-about .about-tree {
  position: relative;
}

.page-about .about-tree__layout {
  display: grid;
  gap: clamp(22px, 3vw, 40px);
  margin-top: clamp(24px, 3vw, 38px);
}

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

.page-about .tree-node {
  align-self: start;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--ink-800);
  overflow: hidden;
  transition: border-color .25s ease, background-color .25s ease;
}

.page-about .tree-node[open] {
  border-color: var(--cyan-40);
  background: var(--ink-700);
}

.page-about .tree-node__head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto auto;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-data);
  font-size: .94rem;
  letter-spacing: .04em;
  color: var(--paper);
}

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

.page-about .tree-node__head::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1rem;
  line-height: 1;
  color: var(--cyan);
}

.page-about .tree-node[open] .tree-node__head::after {
  content: "\2212";
}

.page-about .tree-node__head:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .tree-node__ver {
  font-size: .72rem;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .tree-node__list {
  list-style: none;
  margin: 0;
  padding: 12px 14px 15px;
  display: grid;
  gap: 7px;
  border-top: 1px solid var(--line-soft);
}

.page-about .tree-node__item {
  position: relative;
  padding-left: 15px;
  font-size: .84rem;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .tree-node__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: .68em;
  width: 7px;
  height: 1px;
  background: var(--cyan-40);
}

.page-about .about-tree__figure {
  margin: 0;
  aspect-ratio: 10 / 7;
}

@media (min-width: 700px) {
  .page-about .about-tree__nodes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 980px) {
  .page-about .about-tree__layout {
    grid-template-columns: minmax(0, 1fr) 330px;
    align-items: start;
  }

  .page-about .about-tree__figure {
    position: sticky;
    top: 108px;
  }
}

/* ---------- 批次与索引 ---------- */
.page-about .about-index__grid {
  display: grid;
  gap: 16px;
  margin-top: clamp(24px, 3vw, 38px);
}

.page-about .index-path {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 26px 20px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: linear-gradient(180deg, var(--ink-800), var(--ink-900));
  overflow: hidden;
}

.page-about .index-path::before {
  content: "";
  position: absolute;
  top: 0;
  left: 20px;
  width: 38px;
  height: 3px;
  border-radius: 2px;
  background: var(--cyan);
}

.page-about .index-path:nth-child(3)::before {
  background: var(--orange);
}

.page-about .index-path__num {
  margin: 0;
  color: var(--muted);
}

.page-about .index-path__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: 1.14rem;
  color: var(--paper);
}

.page-about .index-path__text {
  margin: 0;
  font-size: .9rem;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .index-path__chip {
  margin: auto 0 0;
  padding-top: 10px;
}

@media (min-width: 780px) {
  .page-about .about-index__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 团队 ---------- */
.page-about .about-team__grid {
  display: grid;
  gap: clamp(26px, 3.5vw, 52px);
}

.page-about .about-team__lead h2 {
  margin: 12px 0 16px;
  font-family: var(--font-heading);
  font-size: clamp(1.4rem, 2.8vw, 2.05rem);
  line-height: 1.32;
  color: var(--paper);
}

.page-about .about-team__lead p {
  margin: 0 0 14px;
  max-width: 58ch;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-team__link {
  margin-top: 20px;
}

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

.page-about .team-card {
  display: grid;
  grid-template-columns: 78px minmax(0, 1fr);
  gap: 4px 18px;
  padding: 18px 20px;
  border-left: 2px solid var(--cyan-40);
  border-radius: 4px 14px 14px 4px;
  background: var(--ink-800);
}

.page-about .team-card__num {
  grid-column: 1;
  grid-row: 1 / span 2;
  align-self: center;
  margin: 0;
  font-size: 1.85rem;
  line-height: 1;
  color: var(--cyan);
}

.page-about .team-card__role {
  grid-column: 2;
  grid-row: 1;
  margin: 0;
  font-family: var(--font-data);
  font-size: .95rem;
  letter-spacing: .06em;
  color: var(--paper);
}

.page-about .team-card__text {
  grid-column: 2;
  grid-row: 2;
  margin: 0;
  font-size: .86rem;
  line-height: 1.7;
  color: var(--muted);
}

@media (min-width: 900px) {
  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.12fr);
    align-items: start;
  }
}

/* ---------- 合作与荣誉 ---------- */
.page-about .about-partners__grid {
  display: grid;
  gap: clamp(24px, 3vw, 46px);
  margin-top: clamp(24px, 3vw, 38px);
  align-items: center;
}

.page-about .about-partners__text p {
  margin: 0 0 14px;
  max-width: 58ch;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-partners__figure {
  margin: 0;
  aspect-ratio: 12 / 7;
}

.page-about .award-wall {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: clamp(26px, 3.5vw, 42px) 0 0;
  padding: clamp(18px, 2.4vw, 26px) 0 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .award-tag {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 9px 15px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: var(--ink-800);
  color: var(--paper);
  font-size: .82rem;
  letter-spacing: .02em;
  transition: border-color .25s ease, transform .25s ease;
}

.page-about .award-tag::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 9px var(--cyan-40);
}

.page-about .award-tag--warm::before {
  background: var(--orange);
  box-shadow: 0 0 9px var(--orange-20);
}

.page-about .award-tag:hover {
  border-color: var(--cyan-40);
  transform: translateY(-2px);
}

@media (min-width: 900px) {
  .page-about .about-partners__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.18fr);
  }
}

/* ---------- 更新节奏 ---------- */
.page-about .about-cadence__grid {
  display: grid;
  gap: 16px;
  margin-top: clamp(24px, 3vw, 38px);
}

.page-about .cadence-card {
  padding: 24px 22px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: var(--ink-800);
}

.page-about .cadence-card__cycle {
  margin: 0;
  font-family: var(--font-data);
  font-size: .78rem;
  letter-spacing: .16em;
  color: var(--orange);
}

.page-about .cadence-card__title {
  margin: 10px 0 14px;
  font-family: var(--font-heading);
  font-size: 1.15rem;
  color: var(--paper);
}

.page-about .cadence-card__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 9px;
}

.page-about .cadence-card__list li {
  position: relative;
  padding-left: 18px;
  font-size: .89rem;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .cadence-card__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 8px;
  height: 1px;
  background: var(--cyan-40);
}

.page-about .about-cadence__promise {
  display: grid;
  gap: 12px;
  margin-top: 20px;
  padding: 20px 22px;
  border: 1px solid var(--cyan-40);
  border-radius: var(--radius-card);
  background: var(--cyan-12);
}

.page-about .about-cadence__promise-item {
  margin: 0;
  font-size: .89rem;
  line-height: 1.7;
  color: var(--paper);
}

.page-about .about-cadence__promise-item .mono {
  display: inline-block;
  margin-right: 10px;
  color: var(--cyan);
  font-size: .8rem;
  letter-spacing: .1em;
}

@media (min-width: 760px) {
  .page-about .about-cadence__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-cadence__promise {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px 26px;
    align-items: start;
  }
}

/* ---------- 结尾入口 ---------- */
.page-about .about-cta__inner {
  padding: clamp(26px, 4vw, 46px);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background:
    radial-gradient(120% 140% at 100% 0%, var(--cyan-12), transparent 56%),
    var(--ink-800);
}

.page-about .about-cta__inner h2 {
  margin: 0 0 14px;
  font-family: var(--font-heading);
  font-size: clamp(1.3rem, 2.6vw, 1.9rem);
  line-height: 1.35;
  color: var(--paper);
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 66ch;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-cta__links {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 24px 0 0;
  padding: 0;
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .award-tag,
  .page-about .tree-node {
    transition: none;
  }

  .page-about .award-tag:hover {
    transform: none;
  }
}