.page-about {
  --about-line: rgba(255, 255, 255, .18);
  --about-rule: rgba(16, 27, 38, .12);
  --about-mint-glow: rgba(55, 240, 162, .18);
  overflow-x: hidden;
}

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

.page-about .about-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

/* ---------- 页头：专题封面式构图 ---------- */
.page-about .about-hero {
  position: relative;
  padding-top: calc(var(--h-header) + 56px);
  padding-bottom: 76px;
  background:
    radial-gradient(1000px 520px at 92% -18%, rgba(255, 106, 26, .30), transparent 62%),
    radial-gradient(720px 460px at -4% 122%, rgba(55, 240, 162, .14), transparent 60%),
    linear-gradient(180deg, #071F2A 0%, var(--c-teal) 100%);
}

.page-about .about-hero__inner {
  position: relative;
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  margin-top: 26px;
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  color: #fff;
  letter-spacing: -.012em;
}

.page-about .about-hero__lede {
  margin-top: 22px;
  max-width: 46ch;
  color: rgba(255, 255, 255, .78);
}

.page-about .about-hero__index {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--about-line);
}

.page-about .about-hero__index li {
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-hero__index a {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 12px 2px;
  color: rgba(255, 255, 255, .78);
  font-size: 15px;
  text-decoration: none;
  transition: color .16s var(--ease), transform .16s var(--ease);
}

.page-about .about-hero__index a:hover,
.page-about .about-hero__index a:focus-visible {
  color: #fff;
  transform: translateX(6px);
}

.page-about .about-hero__index .about-num {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--c-orange);
}

/* ---------- 章节通用 ---------- */
.page-about .about-sec {
  position: relative;
}

.page-about .about-head {
  margin-bottom: 44px;
}

.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
}

/* ---------- 01 起步 ---------- */
.page-about .about-fact {
  padding: 24px 26px;
  border: 1px solid var(--about-rule);
  border-radius: var(--r-m);
  background: #fff;
  box-shadow: var(--shadow-soft);
}

.page-about .about-fact + .about-fact {
  margin-top: 18px;
}

.page-about .about-fact__label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--c-muted);
  text-transform: uppercase;
}

.page-about .about-fact__value {
  margin: 10px 0 6px;
  font-size: 38px;
  font-weight: 800;
  line-height: 1.05;
  color: var(--c-orange);
}

.page-about .about-fact__text {
  margin: 0;
  color: var(--c-muted);
  font-size: 14.5px;
  line-height: 1.7;
}

/* ---------- 02 团队 ---------- */
.page-about .about-team-figure {
  margin: 0;
}

.page-about .about-team {
  display: grid;
  gap: 16px;
}

.page-about .about-team__item {
  padding: 22px 24px;
  border: 1px solid var(--c-glass-line);
  border-radius: var(--r-m);
  background: var(--c-glass);
  backdrop-filter: blur(10px);
}

.page-about .about-team__tag {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--c-mint);
}

.page-about .about-team__title {
  margin: 8px 0 8px;
  font-size: 20px;
  font-weight: 800;
  color: #fff;
}

.page-about .about-team__text {
  margin: 0;
  color: rgba(255, 255, 255, .72);
  font-size: 15.5px;
  line-height: 1.74;
}

/* ---------- 03 数据来源 ---------- */
.page-about .about-source__map {
  margin-top: 6px;
}

.page-about .about-source__nodes {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-source__node {
  position: relative;
  padding: 22px 24px;
  border: 1px solid var(--about-rule);
  border-radius: var(--r-m);
  background: #fff;
  box-shadow: var(--shadow-soft);
}

.page-about .about-source__num {
  margin: 0;
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--c-orange);
}

.page-about .about-source__name {
  margin: 10px 0 4px;
  font-size: 17px;
  font-weight: 800;
  color: var(--c-ink);
}

.page-about .about-source__desc {
  margin: 0;
  color: var(--c-muted);
  font-size: 14.5px;
  line-height: 1.66;
}

.page-about .about-source__bus {
  height: 2px;
  margin-top: 22px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--c-orange), rgba(255, 106, 26, .25) 42%, rgba(55, 240, 162, .3) 58%, var(--c-mint));
}

.page-about .about-source__bus-label {
  margin: 12px 0 0;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--c-muted);
}

.page-about .about-flow {
  list-style: none;
  margin: 46px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-flow__step {
  padding: 22px 0;
  border-top: 1px solid var(--about-rule);
}

.page-about .about-flow__idx {
  margin: 0;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--c-orange-deep);
}

.page-about .about-flow__step h3 {
  margin: 8px 0 6px;
  font-size: 19px;
  font-weight: 800;
  color: var(--c-ink);
}

.page-about .about-flow__step p {
  margin: 0;
  color: var(--c-muted);
  font-size: 15.5px;
  line-height: 1.72;
}

/* ---------- 04 时间轴 ---------- */
.page-about .about-tl-figure {
  margin: 0 0 52px;
}

.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 40px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-orange), rgba(255, 106, 26, .3) 45%, var(--c-mint));
  opacity: .55;
}

.page-about .about-timeline__item {
  position: relative;
  padding-bottom: 36px;
}

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

.page-about .about-timeline__item::after {
  content: "";
  position: absolute;
  left: -40px;
  top: 5px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--c-orange);
  box-shadow: 0 0 0 5px rgba(255, 106, 26, .16);
}

.page-about .about-timeline__year {
  display: block;
  margin-bottom: 6px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--c-orange);
}

.page-about .about-timeline__title {
  margin: 0 0 8px;
  font-size: 20px;
  font-weight: 800;
  line-height: 1.35;
  color: #fff;
}

.page-about .about-timeline__text {
  margin: 0;
  color: rgba(255, 255, 255, .7);
  font-size: 15.5px;
  line-height: 1.74;
}

/* ---------- 05 清单 ---------- */
.page-about .about-listbox {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  padding: 30px 24px;
  border: 1px solid var(--about-rule);
  border-radius: var(--r-l);
  background: #fff;
  box-shadow: var(--shadow-soft);
}

.page-about .about-listbox__num {
  margin: 16px 0 4px;
  font-size: 60px;
  font-weight: 800;
  line-height: 1;
  color: var(--c-orange);
}

.page-about .about-listbox__cap {
  margin: 0;
  color: var(--c-muted);
  font-size: 15px;
  line-height: 1.66;
}

.page-about .about-listbox__title {
  margin: 0;
  font-size: 21px;
  font-weight: 800;
  color: var(--c-ink);
}

.page-about .about-checks {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-checks li {
  position: relative;
  padding-left: 26px;
  color: var(--c-muted);
  font-size: 15.5px;
  line-height: 1.74;
}

.page-about .about-checks li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 13px;
  height: 2px;
  background: var(--c-orange);
}

/* ---------- 06 回访 ---------- */
.page-about .about-stats-grid {
  gap: 18px;
}

.page-about .about-big-stat {
  padding: 26px 24px;
  border: 1px solid var(--c-glass-line);
  border-radius: var(--r-m);
  background: var(--c-glass);
  backdrop-filter: blur(10px);
}

.page-about .about-big-stat__value {
  margin: 0;
  font-size: 50px;
  font-weight: 700;
  line-height: 1;
  color: var(--c-mint);
}

.page-about .about-big-stat__value span {
  margin-left: 5px;
  font-size: 19px;
  font-weight: 500;
}

.page-about .about-big-stat__label {
  margin: 14px 0 4px;
  font-size: 17px;
  font-weight: 800;
  color: #fff;
}

.page-about .about-big-stat__text {
  margin: 0;
  color: rgba(255, 255, 255, .66);
  font-size: 14.5px;
  line-height: 1.66;
}

.page-about .about-prose-dark {
  max-width: var(--w-prose);
  margin-top: 44px;
  color: rgba(255, 255, 255, .76);
  font-size: 16.5px;
  line-height: 1.8;
}

.page-about .about-prose-dark p {
  margin: 0 0 18px;
}

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

/* ---------- 07 协作 ---------- */
.page-about .about-collab__prose {
  color: rgba(255, 255, 255, .78);
}

.page-about .about-collab__list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 28px 0 0;
  padding: 0;
}

.page-about .about-collab__list li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 20px;
  border: 1px solid var(--c-glass-line);
  border-radius: var(--r-m);
  background: var(--c-glass);
}

.page-about .about-collab__num {
  margin: 0;
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--c-mint);
}

.page-about .about-collab__label {
  margin: 0;
  color: rgba(255, 255, 255, .8);
  font-size: 15px;
  line-height: 1.6;
}

/* ---------- 末段行动色带 ---------- */
.page-about .about-cta {
  padding: 66px 0;
  background: linear-gradient(118deg, var(--c-orange) 0%, var(--c-orange-deep) 58%, #8C2F00 100%);
}

.page-about .about-cta__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}

.page-about .about-cta__eyebrow {
  color: #fff;
}

.page-about .about-cta__eyebrow::before {
  background: rgba(255, 255, 255, .72);
}

.page-about .about-cta__title {
  margin: 10px 0 0;
  color: #fff;
}

.page-about .about-cta__text {
  margin: 16px 0 0;
  max-width: 62ch;
  color: rgba(255, 255, 255, .88);
  line-height: 1.76;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ================= 响应式 ================= */
@media (min-width: 700px) {
  .page-about .about-source__nodes {
    grid-template-columns: repeat(3, 1fr);
    gap: 22px;
    padding-bottom: 26px;
  }

  .page-about .about-source__node::after {
    content: "";
    position: absolute;
    left: 50%;
    bottom: -26px;
    width: 2px;
    height: 26px;
    margin-left: -1px;
    background: var(--c-orange);
    opacity: .45;
  }

  .page-about .about-source__bus {
    margin-top: 0;
  }

  .page-about .about-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 48px;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero {
    padding-top: calc(var(--h-header) + 84px);
    padding-bottom: 96px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1fr) 268px;
    gap: 72px;
    align-items: end;
    margin-top: 34px;
  }

  .page-about .about-head {
    margin-bottom: 56px;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, .85fr);
    gap: 64px;
    align-items: start;
  }

  .page-about .about-split--media {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 52px;
    align-items: center;
  }

  .page-about .about-split--flip > :first-child {
    order: 2;
  }

  .page-about .about-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    column-gap: 34px;
  }

  .page-about .about-listbox {
    grid-template-columns: 260px minmax(0, 1fr);
    gap: 52px;
    padding: 46px 52px;
  }

  .page-about .about-stats-grid {
    gap: 24px;
  }

  .page-about .about-cta {
    padding: 78px 0;
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 56px;
  }

  /* 时间轴：主轴居中，左右交替叙事 */
  .page-about .about-timeline {
    padding: 0;
  }

  .page-about .about-timeline::before {
    left: 50%;
    top: 8px;
    bottom: 8px;
    width: 2px;
    margin-left: -1px;
    opacity: .6;
  }

  .page-about .about-timeline__item {
    width: calc(50% - 52px);
    padding-bottom: 54px;
    text-align: right;
  }

  .page-about .about-timeline__item:nth-child(even) {
    margin-left: auto;
    text-align: left;
  }

  .page-about .about-timeline__item::after {
    top: 5px;
    left: auto;
  }

  .page-about .about-timeline__item:nth-child(odd)::after {
    right: -58px;
  }

  .page-about .about-timeline__item:nth-child(even)::after {
    left: -58px;
  }
}