.page-about {
  --paper-link: #8A5A0B;
  --tl-axis: rgba(52, 69, 127, 0.55);
  display: block;
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  padding: clamp(92px, 15vw, 168px) 0 clamp(44px, 7vw, 84px);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(58% 52% at 80% 14%, rgba(47, 227, 214, 0.16), transparent 72%),
    radial-gradient(70% 62% at 14% 92%, rgba(255, 194, 75, 0.13), transparent 72%);
}

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

.page-about .about-hero__title {
  margin: 14px 0 0;
  max-width: 15em;
  color: var(--cream);
}

.page-about .about-hero__lead {
  margin: clamp(20px, 3vw, 30px) 0 0;
  max-width: 42em;
  color: var(--mist);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: clamp(30px, 5vw, 52px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.page-about .about-hero__fact {
  border: 3px solid var(--orbit);
  border-radius: var(--r-sm);
  background: rgba(23, 16, 67, 0.62);
  padding: 14px 16px;
}

.page-about .about-hero__fact b {
  display: block;
  font-family: var(--mono);
  font-size: clamp(22px, 4vw, 30px);
  font-weight: 800;
  line-height: 1.1;
  color: var(--gold);
}

.page-about .about-hero__fact span {
  display: block;
  margin-top: 6px;
  font-size: 13.5px;
  color: var(--mist);
}

/* ============ 章节头部 ============ */
.page-about .sec-head {
  display: flex;
  align-items: flex-start;
  gap: clamp(12px, 3vw, 26px);
  margin-bottom: clamp(24px, 4vw, 44px);
}

.page-about .sec-head .sec-num {
  flex: none;
  font-family: var(--mono);
  font-weight: 800;
  font-size: clamp(40px, 8vw, 88px);
  line-height: 0.88;
  letter-spacing: -0.02em;
  color: transparent;
  -webkit-text-stroke: 2px rgba(167, 178, 217, 0.45);
}

.page-about .sec-head .sec-num.is-lit {
  color: var(--gold);
  -webkit-text-stroke: 2px var(--gold);
}

.page-about .sec-head .h2 {
  margin: 0;
  align-self: center;
}

/* ============ 01 起步 ============ */
.page-about .about-start {
  padding: clamp(40px, 7vw, 72px) 0 clamp(48px, 8vw, 96px);
}

.page-about .about-start__grid {
  display: grid;
  gap: clamp(26px, 5vw, 48px);
}

.page-about .about-start__text p {
  margin: 0 0 1.1em;
  color: var(--mist);
  line-height: 1.85;
  max-width: 46em;
}

.page-about .about-start__text p:last-child {
  margin-bottom: 0;
  color: var(--gold-soft);
}

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

/* ============ 02 时间轴 ============ */
.page-about .about-timeline {
  position: relative;
  padding: clamp(56px, 9vw, 112px) 0;
  overflow: hidden;
}

.page-about .about-timeline__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.page-about .about-timeline__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.3;
}

.page-about .about-timeline__bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    var(--deep) 0%,
    rgba(6, 10, 28, 0.45) 26%,
    rgba(6, 10, 28, 0.45) 74%,
    var(--deep) 100%
  );
}

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

.page-about .about-timeline__list {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(22px, 4vw, 38px);
}

.page-about .about-timeline__list::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, transparent, var(--cyan) 14%, var(--gold) 86%, transparent);
  opacity: 0.6;
}

.page-about .tl-node {
  position: relative;
  padding-left: 42px;
}

.page-about .tl-node__dot {
  position: absolute;
  left: 0;
  top: 16px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--deep);
  border: 3px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(47, 227, 214, 0.12);
}

.page-about .tl-node__year {
  display: block;
  font-family: var(--mono);
  font-weight: 800;
  font-size: clamp(30px, 6vw, 52px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: rgba(167, 178, 217, 0.55);
  transition: color 0.3s var(--ease);
}

.page-about .tl-node__year.is-lit {
  color: var(--gold);
}

.page-about .tl-node__card {
  margin-top: 12px;
  padding: clamp(18px, 3vw, 26px);
  border: 3px solid var(--orbit);
  border-radius: 4px 26px 4px 4px;
  background: rgba(23, 16, 67, 0.78);
  box-shadow: var(--bang-dark);
}

.page-about .tl-node__title {
  margin: 0;
  font-size: clamp(18px, 2.4vw, 22px);
  font-weight: 800;
  color: var(--cream);
  line-height: 1.4;
}

.page-about .tl-node__card p {
  margin: 10px 0 0;
  color: var(--mist);
  line-height: 1.8;
}

.page-about .tl-more {
  margin-top: 14px;
  border-top: 1px solid rgba(52, 69, 127, 0.6);
  padding-top: 12px;
}

.page-about .tl-more summary {
  list-style: none;
  cursor: pointer;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

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

.page-about .tl-more summary::after {
  content: " ＋";
  font-family: var(--mono);
}

.page-about .tl-more[open] summary::after {
  content: " －";
}

.page-about .tl-more p {
  color: var(--mist);
  font-size: 15px;
}

/* ============ 03 团队 ============ */
.page-about .about-team {
  padding: clamp(48px, 8vw, 96px) 0;
}

.page-about .about-team__grid {
  display: grid;
  gap: clamp(28px, 5vw, 48px);
}

.page-about .about-team__viz svg {
  display: block;
  width: 100%;
  max-width: 330px;
  height: auto;
  margin: 0 auto;
}

.page-about .ring {
  opacity: 0.82;
  transition: stroke-width 0.24s var(--ease), opacity 0.24s var(--ease);
}

.page-about .ring:hover {
  stroke-width: 30;
  opacity: 1;
}

.page-about .ring--data {
  stroke: var(--gold);
}

.page-about .ring--edit {
  stroke: var(--cyan);
}

.page-about .ring--service {
  stroke: var(--orbit);
}

.page-about .ring--ops {
  stroke: var(--gold-soft);
}

.page-about .ring-num {
  font-family: var(--mono);
  font-size: 40px;
  font-weight: 800;
  fill: var(--gold);
}

.page-about .ring-unit {
  font-family: var(--sans);
  font-size: 13px;
  letter-spacing: 0.1em;
  fill: var(--mist);
}

.page-about .about-team__note {
  margin: 14px 0 0;
  text-align: center;
  color: var(--mist);
}

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

.page-about .team-card {
  border: 3px solid var(--orbit);
  border-left-width: 6px;
  border-radius: var(--r-sm);
  background: rgba(23, 16, 67, 0.6);
  padding: 16px 18px;
  transition: transform 0.24s var(--ease), border-color 0.24s var(--ease);
}

.page-about .team-card:hover {
  transform: translate(4px, -4px);
  border-color: var(--cyan);
}

.page-about .team-card--data {
  border-left-color: var(--gold);
}

.page-about .team-card--edit {
  border-left-color: var(--cyan);
}

.page-about .team-card--service {
  border-left-color: var(--orbit);
}

.page-about .team-card--ops {
  border-left-color: var(--gold-soft);
}

.page-about .team-card__title {
  margin: 0;
  font-size: 17px;
  font-weight: 800;
  color: var(--cream);
}

.page-about .team-card p {
  margin: 8px 0 0;
  color: var(--mist);
  font-size: 15px;
  line-height: 1.8;
}

.page-about .about-team__rhythm {
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 18px 20px;
  border-left: 4px solid var(--cyan);
  background: rgba(6, 10, 28, 0.5);
  color: var(--mist);
  line-height: 1.85;
  max-width: 52em;
}

/* ============ 04 规模 ============ */
.page-about .about-scale {
  padding: clamp(48px, 8vw, 96px) 0;
}

.page-about .about-scale__grid {
  display: grid;
  gap: clamp(28px, 5vw, 44px);
}

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

.page-about .scale-card {
  border: 3px solid var(--orbit);
  border-radius: var(--r-sm);
  background: rgba(6, 10, 28, 0.58);
  padding: 16px 18px;
  display: grid;
  gap: 4px;
}

.page-about .scale-card__num {
  font-family: var(--mono);
  font-size: clamp(26px, 4.4vw, 38px);
  font-weight: 800;
  line-height: 1.05;
  color: var(--gold);
}

.page-about .scale-card__label {
  font-size: 14px;
  font-weight: 700;
  color: var(--cream);
}

.page-about .scale-card__note {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--mist);
}

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

.page-about .about-scale__fig figcaption {
  margin-top: 12px;
  color: var(--mist);
  text-align: center;
}

/* ============ 05 合作与运营 ============ */
.page-about .about-ops {
  padding: clamp(48px, 8vw, 96px) 0;
}

.page-about .ops-grid {
  display: grid;
  gap: 18px;
}

.page-about .ops-card {
  background: var(--cream);
  color: var(--ink);
  border: 3px solid var(--ink);
  border-radius: var(--r-sm);
  box-shadow: var(--bang);
  padding: clamp(18px, 3vw, 26px);
}

.page-about .ops-card__title {
  margin: 0;
  font-size: 19px;
  font-weight: 800;
  color: var(--ink);
}

.page-about .ops-card p {
  margin: 10px 0 0;
  color: var(--ink);
  line-height: 1.85;
  opacity: 0.9;
}

.page-about .ops-card a {
  color: var(--paper-link);
  text-decoration: underline;
}

/* ============ 06 下一步 ============ */
.page-about .about-next {
  padding: clamp(48px, 8vw, 96px) 0 clamp(64px, 10vw, 120px);
}

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

.page-about .next-item {
  position: relative;
  padding: 18px 20px 18px 46px;
  border: 3px solid var(--orbit);
  border-radius: 22px 4px 22px 4px;
  background: rgba(23, 16, 67, 0.55);
}

.page-about .next-item::before {
  content: "";
  position: absolute;
  left: 20px;
  top: 26px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(47, 227, 214, 0.14);
}

.page-about .next-item__title {
  margin: 0;
  font-size: 17px;
  font-weight: 800;
  color: var(--gold-soft);
}

.page-about .next-item p {
  margin: 8px 0 0;
  color: var(--mist);
  font-size: 15px;
  line-height: 1.8;
}

.page-about .about-next__links {
  margin-top: clamp(28px, 4vw, 44px);
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ============ 响应式 ============ */
@media (min-width: 760px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-start__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .tl-node {
    display: grid;
    grid-template-columns: 170px minmax(0, 1fr);
    gap: clamp(18px, 3vw, 34px);
    align-items: start;
    padding-left: 60px;
  }

  .page-about .tl-node__dot {
    top: 22px;
  }

  .page-about .tl-node__year {
    margin-top: 8px;
  }

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

@media (min-width: 960px) {
  .page-about .about-team__grid {
    grid-template-columns: 340px minmax(0, 1fr);
    align-items: center;
  }

  .page-about .about-scale__grid {
    grid-template-columns: minmax(0, 1fr) 360px;
    align-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ring,
  .page-about .team-card,
  .page-about .tl-node__year {
    transition: none;
  }

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