.page-about {
  --about-dot: rgba(169, 182, 217, 0.14);
  --about-gap: clamp(20px, 3.2vw, 42px);
  --about-block: clamp(44px, 7vw, 96px);
  --about-ink-soft: #4B5372;
  position: relative;
  padding-bottom: var(--about-block);
  background-color: var(--deep);
  background-image:
    radial-gradient(circle at 12% 4%, rgba(91, 63, 214, 0.30), transparent 40%),
    radial-gradient(circle at 88% 14%, rgba(53, 224, 214, 0.12), transparent 34%),
    radial-gradient(circle at 46% 88%, rgba(255, 111, 165, 0.09), transparent 40%);
  background-repeat: no-repeat;
  font-size: var(--fs-body);
  color: var(--ink);
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image: radial-gradient(circle, var(--about-dot) 1px, transparent 1.3px);
  background-size: 46px 46px;
  opacity: 0.5;
}

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

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

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

/* ---------- 顶部面包屑 ---------- */

.page-about .about-topline {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 20px;
  padding-top: clamp(24px, 4vw, 52px);
}

.page-about .about-coord {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  font-size: var(--fs-note);
  color: var(--muted);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  display: grid;
  gap: var(--about-gap);
  padding-top: clamp(24px, 4vw, 54px);
  padding-bottom: clamp(36px, 6vw, 84px);
}

.page-about .about-hero .eyebrow {
  margin: 0;
}

.page-about .about-hero .display-hero {
  margin: 10px 0 0;
  max-width: 18ch;
}

.page-about .about-hero .lede {
  margin: 22px 0 0;
  max-width: 52ch;
  color: var(--muted);
}

.page-about .about-hero .meta-line {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  margin: 28px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-size: var(--fs-note);
  color: var(--muted);
}

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

.page-about .about-hero__frame {
  border-radius: var(--radius);
}

.page-about .about-hero__figure .media-caption {
  margin-top: 14px;
  font-size: var(--fs-note);
  color: var(--muted);
  line-height: 1.7;
}

/* ---------- 正文骨架 ---------- */

.page-about .about-body {
  padding-top: clamp(16px, 3vw, 32px);
}

.page-about .about-body__grid {
  display: grid;
  gap: var(--about-gap);
}

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

/* ---------- 章节 ---------- */

.page-about .about-chapter {
  padding-block: clamp(32px, 5vw, 68px);
  border-top: 1px solid var(--line);
}

.page-about .about-body__stack > .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-chapter__head {
  position: relative;
  padding-left: clamp(16px, 2.2vw, 26px);
  margin-bottom: clamp(18px, 2.6vw, 32px);
}

.page-about .about-chapter__head::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 3px;
  background: linear-gradient(180deg, var(--purple), var(--cyan));
}

.page-about .about-chapter__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.2em;
  color: var(--cyan);
  margin-bottom: 8px;
}

.page-about .about-chapter__title {
  margin: 0;
  font-size: var(--fs-h2);
  line-height: 1.25;
  color: var(--ink);
}

.page-about .about-chapter__intro {
  margin: 0 0 1.2em;
  max-width: 60ch;
  color: var(--muted);
}

.page-about .about-chapter__prose p {
  margin: 0 0 1.1em;
  max-width: 62ch;
  color: var(--muted);
  line-height: 1.9;
}

.page-about .about-chapter__prose p strong {
  color: var(--ink);
  font-weight: 600;
}

.page-about .about-chapter__prose--after {
  margin-top: clamp(22px, 3.4vw, 38px);
  max-width: 68ch;
}

.page-about .about-chapter__tail {
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  max-width: 62ch;
  color: var(--muted);
  line-height: 1.9;
}

/* ---------- 纸面插页：四组分工 ---------- */

.page-about .about-paper {
  position: relative;
  margin-block: clamp(30px, 5vw, 64px);
  padding: clamp(22px, 3.6vw, 48px);
  background: var(--paper);
  color: var(--paper-ink);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-paper);
}

.page-about .about-paper__eyebrow {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  color: var(--purple);
  margin-bottom: 10px;
}

.page-about .about-paper__title {
  margin: 0;
  font-size: var(--fs-h2);
  line-height: 1.25;
  color: var(--paper-ink);
}

.page-about .about-paper__lede {
  margin: 16px 0 0;
  max-width: 60ch;
  font-size: 0.98rem;
  line-height: 1.85;
  color: var(--about-ink-soft);
}

.page-about .about-team {
  display: grid;
  gap: clamp(22px, 3.4vw, 40px);
  margin-top: clamp(22px, 3.4vw, 40px);
}

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

.page-about .about-team-map__core {
  grid-column: 1 / -1;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 4px;
  padding: 20px 18px;
  border-radius: 999px;
  background: radial-gradient(circle at 50% 38%, rgba(91, 63, 214, 0.55), rgba(10, 17, 48, 0.94));
  border: 1px solid var(--cyan);
  color: var(--ink);
  text-align: center;
}

.page-about .about-team-map__core-num {
  font-size: 2.2rem;
  line-height: 1;
  color: var(--ink);
}

.page-about .about-team-map__core-label {
  font-size: 0.76rem;
  letter-spacing: 0.1em;
  color: rgba(234, 240, 255, 0.72);
}

.page-about .about-team-map__cell {
  display: block;
  padding: 14px 16px;
  background: #FFFFFF;
  border: 1px solid #D8D2C4;
  border-radius: var(--radius);
  transition: transform 200ms ease, box-shadow 200ms ease, border-color 200ms ease;
}

.page-about .about-team-map__cell:hover,
.page-about .about-team-map__cell:focus-within,
.page-about .about-team-map__cell:focus {
  transform: translateY(-4px);
  border-color: var(--purple);
  box-shadow: 0 8px 0 rgba(91, 63, 214, 0.22);
  outline: none;
}

.page-about .about-team-map__name {
  display: block;
  font-size: 1rem;
  font-weight: 700;
  color: var(--paper-ink);
  margin-bottom: 6px;
}

.page-about .about-team-map__duty {
  display: block;
  font-size: 0.86rem;
  line-height: 1.72;
  color: var(--about-ink-soft);
}

.page-about .about-team-map__out {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.04em;
  color: #5B3FD6;
  opacity: 0.6;
  transition: opacity 200ms ease;
}

.page-about .about-team-map__cell:hover .about-team-map__out,
.page-about .about-team-map__cell:focus-within .about-team-map__out,
.page-about .about-team-map__cell:focus .about-team-map__out {
  opacity: 1;
}

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

.page-about .about-team__figure .media-frame {
  border-radius: var(--radius);
  border: 1px solid #D8D2C4;
  overflow: hidden;
  background: linear-gradient(150deg, #E8E2D4 0%, #DCD6E8 60%, #CFE9E6 100%);
}

.page-about .about-team__figure .media-caption {
  margin-top: 12px;
  font-size: 0.8rem;
  line-height: 1.7;
  color: var(--about-ink-soft);
}

/* ---------- 时间轴 ---------- */

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

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--purple), var(--cyan) 55%, var(--pink));
  opacity: 0.45;
}

.page-about .about-node {
  position: relative;
  padding-left: 34px;
  padding-bottom: 16px;
}

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

.page-about .about-node__marker {
  position: absolute;
  left: 0;
  top: 12px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid var(--cyan);
  background: var(--deep);
  box-shadow: 0 0 0 4px rgba(53, 224, 214, 0.12);
}

.page-about .about-node__trigger {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 10px 0 12px;
  background: none;
  border: 0;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
  font: inherit;
  text-align: left;
  cursor: pointer;
}

.page-about .about-node__trigger:hover .about-node__label,
.page-about .about-node__trigger:focus-visible .about-node__label {
  color: var(--cyan);
}

.page-about .about-node__trigger:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .about-node__years {
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  color: var(--gold);
  white-space: nowrap;
}

.page-about .about-node__label {
  font-size: 1.05rem;
  font-weight: 600;
  transition: color 180ms ease;
}

.page-about .about-node__panel p {
  margin: 0;
  padding-top: 14px;
  max-width: 62ch;
  font-size: 0.95rem;
  line-height: 1.9;
  color: var(--muted);
}

/* ---------- 更新节奏 ---------- */

.page-about .about-cadence {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-cadence__item {
  padding: clamp(20px, 3vw, 30px);
  background: var(--deep-2);
}

.page-about .about-cadence__num {
  display: inline-block;
  padding: 4px 11px;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--gold);
  border: 1px solid rgba(242, 184, 75, 0.5);
  border-radius: var(--radius);
}

.page-about .about-cadence__title {
  margin: 16px 0 10px;
  font-size: var(--fs-h3);
  line-height: 1.35;
  color: var(--ink);
}

.page-about .about-cadence__item p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 协作伙伴 ---------- */

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

.page-about .about-partner {
  padding: 18px 20px;
  background: linear-gradient(120deg, rgba(16, 26, 61, 0.9), rgba(10, 17, 48, 0.9));
  border: 1px solid var(--line);
  border-left: 3px solid var(--purple);
  border-radius: var(--radius);
}

.page-about .about-partner p {
  margin: 12px 0 0;
  font-size: 0.94rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-partners-figure {
  margin: clamp(24px, 3.6vw, 44px) 0 0;
}

.page-about .about-partners-figure .media-frame {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: linear-gradient(120deg, #0A1130 0%, #231A5C 45%, #0E3B49 100%);
}

.page-about .about-partners-figure .media-caption {
  margin-top: 12px;
  font-size: var(--fs-note);
  color: var(--muted);
  line-height: 1.7;
}

/* ---------- 下一步 ---------- */

.page-about .about-chapter--next {
  border-top: 1px solid var(--line);
}

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

.page-about .about-next__link {
  display: block;
  height: 100%;
  padding: 20px 22px;
  background: var(--deep-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--ink);
  transition: transform 200ms ease, border-color 200ms ease, box-shadow 200ms ease;
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  transform: translateY(-4px);
  border-color: var(--cyan);
  box-shadow: var(--shadow-paper-sm);
  outline: none;
}

.page-about .about-next__label {
  display: block;
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.page-about .about-next__desc {
  display: block;
  font-size: 0.88rem;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 章节轨道 ---------- */

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

/* ---------- 响应式 ---------- */

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

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

@media (min-width: 940px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    column-gap: clamp(32px, 5vw, 72px);
    align-items: end;
  }

  .page-about .about-hero__figure {
    transform: translateY(clamp(-34px, -3vw, -10px));
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: center;
  }

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

@media (min-width: 1024px) {
  .page-about .about-body__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 190px);
    column-gap: clamp(28px, 4vw, 60px);
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 104px;
    padding-left: 2px;
  }

  .page-about .about-rail__title {
    margin: 0 0 14px;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.24em;
    color: var(--muted);
  }

  .page-about .about-rail__list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 2px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail__list a {
    display: block;
    padding: 7px 0 7px 14px;
    margin-left: -1px;
    font-size: 0.86rem;
    color: var(--muted);
    text-decoration: none;
    border-left: 2px solid transparent;
    transition: color 180ms ease, border-color 180ms ease;
  }

  .page-about .about-rail__list a .num {
    font-size: 0.72rem;
    margin-right: 6px;
    color: rgba(169, 182, 217, 0.7);
  }

  .page-about .about-rail__list a:hover,
  .page-about .about-rail__list a:focus-visible {
    color: var(--cyan);
    border-left-color: var(--cyan);
    outline: none;
  }

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

  .page-about .about-team-map__core {
    grid-area: 2 / 2;
    grid-column: auto;
    aspect-ratio: 1 / 1;
  }

  .page-about .about-team-map__cell--a { grid-area: 1 / 1; }
  .page-about .about-team-map__cell--b { grid-area: 1 / 3; }
  .page-about .about-team-map__cell--c { grid-area: 3 / 1; }
  .page-about .about-team-map__cell--d { grid-area: 3 / 3; }
}

@media (min-width: 1180px) {
  .page-about .about-cadence {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}