.page-about {
  --about-panel: clamp(1.1rem, 4vw, 3rem);
  background:
    radial-gradient(120% 55% at 84% -8%, rgba(201, 162, 39, 0.14), transparent 62%),
    radial-gradient(90% 50% at 0% 40%, rgba(46, 125, 107, 0.12), transparent 70%),
    var(--c-ark);
  color: rgba(244, 237, 223, 0.88);
  font-family: var(--font-body);
  padding-bottom: clamp(2.6rem, 7vw, 5.5rem);
  overflow-x: hidden;
}

.page-about .about-hero {
  padding: clamp(1.5rem, 5vw, 3.2rem) 0 clamp(1.8rem, 5vw, 3.4rem);
}

.page-about .breadcrumb {
  margin-bottom: clamp(0.9rem, 2.6vw, 1.6rem);
}

.page-about .about-frame {
  position: relative;
  border: 1px solid var(--line-gold);
  background: linear-gradient(155deg, rgba(28, 37, 84, 0.94), rgba(14, 20, 54, 0.97));
  box-shadow: var(--shadow-float);
  padding: var(--about-panel);
  overflow: hidden;
}

.page-about .about-frame::before {
  content: "";
  position: absolute;
  inset: 8px;
  border: 1px solid rgba(239, 221, 164, 0.13);
  pointer-events: none;
}

.page-about .about-frame::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 46%;
  height: 2px;
  background: linear-gradient(90deg, var(--c-gold-hi), rgba(201, 162, 39, 0));
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(1.3rem, 4vw, 2.6rem);
  align-items: start;
}

.page-about .mono-tag {
  display: inline-block;
}

.page-about h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2rem, 7.4vw, 4.6rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--c-paper);
  margin: 0.7rem 0 1rem;
  text-wrap: balance;
}

.page-about .about-hero__dek {
  font-size: clamp(1rem, 2.6vw, 1.12rem);
  line-height: 1.85;
  max-width: 34em;
  color: rgba(244, 237, 223, 0.82);
  margin: 0 0 clamp(1.2rem, 3vw, 1.8rem);
}

.page-about .about-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem 1.2rem;
  border-top: 1px solid var(--line-soft);
  padding-top: clamp(0.9rem, 3vw, 1.4rem);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.page-about .about-stat__num {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 5vw, 2.1rem);
  line-height: 1.1;
  color: var(--c-gold-hi);
  letter-spacing: -0.01em;
}

.page-about .about-stat__label {
  font-size: 0.82rem;
  letter-spacing: 0.02em;
  color: var(--c-mist);
}

.page-about .about-hero__figure {
  margin: 0;
  border: 1px solid var(--line-gold);
  background: var(--c-hull);
  box-shadow: var(--shadow-panel);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

.page-about .about-body {
  padding-top: clamp(0.6rem, 2vw, 1.4rem);
}

.page-about .about-layout {
  display: grid;
  gap: clamp(1.4rem, 4vw, 3rem);
}

/* 章节索引：窄屏横向滑条 */
.page-about .about-toc {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  padding-bottom: 0.5rem;
  scrollbar-width: thin;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-toc .toc__title {
  display: none;
}

.page-about .about-toc .toc__link {
  flex: 0 0 auto;
  white-space: nowrap;
  font-size: 0.86rem;
  color: rgba(244, 237, 223, 0.72);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-pill);
  padding: 0.4rem 0.85rem;
  text-decoration: none;
}

.page-about .about-toc .toc__link[aria-current="true"] {
  color: var(--c-ark);
  background: var(--c-gold-hi);
  border-color: var(--c-gold-hi);
}

.page-about .about-toc .toc__num {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  margin-right: 0.45rem;
  opacity: 0.75;
}

.page-about .about-toc__shortcut {
  flex: 0 0 auto;
  white-space: nowrap;
  align-self: center;
  font-size: 0.82rem;
  color: var(--c-gold);
  text-decoration: none;
  padding: 0.4rem 0.5rem;
  border-bottom: 1px solid var(--line-gold);
}

.page-about .about-content {
  display: flex;
  flex-direction: column;
  gap: clamp(2.2rem, 6vw, 4.2rem);
  min-width: 0;
}

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

.page-about .about-sec__num {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  color: var(--c-gold);
  margin: 0 0 0.5rem;
}

.page-about .about-sec__num--ink {
  color: var(--c-cinnabar);
}

.page-about .about-sec__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.45rem, 4.6vw, 2.4rem);
  line-height: 1.24;
  letter-spacing: -0.015em;
  color: var(--c-paper);
  margin: 0 0 0.9rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-sec__title--ink {
  color: var(--c-ink);
  border-bottom-color: rgba(36, 31, 24, 0.16);
}

.page-about .about-sec__lead {
  font-size: 1rem;
  line-height: 1.85;
  color: rgba(244, 237, 223, 0.78);
  max-width: 36em;
  margin: 0 0 clamp(1.1rem, 3vw, 1.7rem);
}

.page-about .about-cols {
  display: grid;
  gap: clamp(1rem, 3vw, 2rem);
}

.page-about .about-prose {
  max-width: 38em;
}

.page-about .about-prose p {
  margin: 0 0 1rem;
  font-size: 1rem;
  line-height: 1.9;
  color: rgba(244, 237, 223, 0.85);
}

.page-about .about-side {
  border-left: 2px solid var(--c-gold);
  padding: 0.2rem 0 0.2rem 1rem;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--c-mist);
}

.page-about .about-side p {
  margin: 0;
}

.page-about .about-side__tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--c-gold);
  margin-bottom: 0.4rem !important;
}

/* 四条主题线 */
.page-about .line-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.page-about .line-card {
  position: relative;
  border: 1px solid var(--line-soft);
  border-top-width: 3px;
  background: linear-gradient(170deg, rgba(28, 37, 84, 0.85), rgba(14, 20, 54, 0.9));
  box-shadow: var(--shadow-float);
  padding: 0.9rem 1rem 1.2rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.page-about .line-card--beast { border-top-color: var(--c-cinnabar); }
.page-about .line-card--cloud { border-top-color: var(--c-jade); }
.page-about .line-card--seal { border-top-color: var(--c-gold); }
.page-about .line-card--raft { border-top-color: #4A5FA8; }

.page-about .line-card__fig {
  margin: 0 0 0.4rem;
  border: 1px solid var(--line-soft);
  background: var(--c-hull);
  overflow: hidden;
}

.page-about .line-card__fig img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
}

.page-about .line-card__tag {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.3rem;
  letter-spacing: 0.06em;
  color: var(--c-paper);
  margin: 0;
}

.page-about .line-card--beast .line-card__tag { color: #E0715F; }
.page-about .line-card--cloud .line-card__tag { color: #57B49E; }
.page-about .line-card--seal .line-card__tag { color: var(--c-gold-hi); }
.page-about .line-card--raft .line-card__tag { color: #8FA3E0; }

.page-about .line-card__count {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  color: var(--c-mist);
  margin: 0;
}

.page-about .line-card__text {
  font-size: 0.94rem;
  line-height: 1.85;
  color: rgba(244, 237, 223, 0.8);
  margin: 0;
}

/* 人群参考 · 奶油纸面板 */
.page-about .about-paper {
  position: relative;
  background: var(--c-paper);
  color: var(--c-ink);
  border-top: 4px solid var(--c-gold);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-panel);
  padding: clamp(1.1rem, 4vw, 2.6rem);
}

.page-about .about-paper__lead {
  max-width: 36em;
  margin: 0 0 clamp(1.1rem, 3vw, 1.6rem);
  color: rgba(36, 31, 24, 0.82);
}

.page-about .people-rail {
  list-style: none;
  margin: 0;
  padding: 0 0 0.6rem;
  display: flex;
  gap: 0.9rem;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.page-about .people-card {
  flex: 0 0 min(84%, 21rem);
  scroll-snap-align: start;
  background: var(--c-letter);
  border: 1px solid rgba(36, 31, 24, 0.14);
  border-left: 4px solid var(--c-jade);
  border-radius: 10px;
  padding: 1rem 1rem 1.1rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.page-about .people-card__coord {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--c-cinnabar);
  margin: 0;
}

.page-about .people-card__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.08rem;
  line-height: 1.4;
  color: var(--c-ink);
  margin: 0;
}

.page-about .people-card__text {
  font-size: 0.92rem;
  line-height: 1.85;
  color: rgba(36, 31, 24, 0.82);
  margin: 0;
}

.page-about .people-card__start,
.page-about .people-card__done {
  font-size: 0.86rem;
  line-height: 1.75;
  color: rgba(36, 31, 24, 0.72);
  margin: 0;
  padding-top: 0.5rem;
  border-top: 1px dashed rgba(36, 31, 24, 0.2);
}

.page-about .people-card a {
  color: var(--c-jade);
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid rgba(46, 125, 107, 0.5);
}

/* 内容生产 */
.page-about .craft-fig {
  margin: 0 0 clamp(1.1rem, 3vw, 1.8rem);
  border: 1px solid var(--line-gold);
  background: var(--c-hull);
  box-shadow: var(--shadow-panel);
}

.page-about .craft-fig img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 12 / 7;
  object-fit: cover;
}

.page-about .craft-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.page-about .craft-step {
  border-top: 1px solid var(--line-soft);
  padding-top: 0.85rem;
}

.page-about .craft-step__num {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.12em;
  color: var(--c-gold);
}

.page-about .craft-step__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--c-paper);
  margin: 0.35rem 0 0.4rem;
}

.page-about .craft-step p {
  font-size: 0.94rem;
  line-height: 1.85;
  color: rgba(244, 237, 223, 0.78);
  margin: 0;
}

.page-about .about-quote {
  margin: clamp(1.2rem, 3vw, 1.8rem) 0 0;
  padding: 0.9rem 0 0.9rem 1rem;
  border-left: 3px solid var(--c-gold);
  background: rgba(28, 37, 84, 0.55);
  font-size: 0.94rem;
  line-height: 1.85;
  color: rgba(244, 237, 223, 0.84);
}

/* 时间轴 */
.page-about .about-timeline {
  position: relative;
  margin: 0;
  padding-left: 1.5rem;
  border-left: 1px solid var(--line-gold);
}

.page-about .tl-node {
  position: relative;
  padding: 0 0 0.35rem;
}

.page-about .tl-node__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.55rem;
  cursor: pointer;
  list-style: none;
  padding: 0.6rem 0 0.55rem;
  border-bottom: 1px solid var(--line-soft);
}

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

.page-about .tl-node__head::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--c-gold);
}

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

.page-about .tl-node__dot {
  position: absolute;
  left: calc(-1.5rem - 0.35rem);
  top: 1.15rem;
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 50%;
  background: var(--c-gold);
  box-shadow: 0 0 0 4px rgba(201, 162, 39, 0.16);
}

.page-about .tl-node__tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--c-gold-hi);
  border: 1px solid var(--line-gold);
  border-radius: var(--radius-pill);
  padding: 0.12rem 0.55rem;
}

.page-about .tl-node__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.02rem;
  color: var(--c-paper);
}

.page-about .tl-node__body {
  font-size: 0.93rem;
  line-height: 1.85;
  color: rgba(244, 237, 223, 0.78);
  margin: 0.6rem 0 0.9rem;
  max-width: 36em;
}

/* 方舟计划 */
.page-about .plan-panel {
  position: relative;
  border: 1px solid rgba(46, 125, 107, 0.5);
  border-left: 4px solid var(--c-jade);
  background: linear-gradient(160deg, rgba(46, 125, 107, 0.16), rgba(14, 20, 54, 0.9));
  box-shadow: var(--shadow-panel);
  padding: clamp(1.1rem, 4vw, 2.4rem);
}

.page-about .plan-lead {
  font-size: 0.98rem;
  line-height: 1.9;
  color: rgba(244, 237, 223, 0.84);
  max-width: 36em;
  margin: 0 0 clamp(1rem, 3vw, 1.5rem);
}

.page-about .plan-ways {
  list-style: none;
  margin: 0 0 clamp(1rem, 3vw, 1.5rem);
  padding: 0;
  display: grid;
  gap: 0.9rem;
}

.page-about .plan-way {
  border-top: 1px solid var(--line-soft);
  padding-top: 0.8rem;
}

.page-about .plan-way .mono-tag {
  font-size: 0.74rem;
}

.page-about .plan-way p {
  font-size: 0.93rem;
  line-height: 1.85;
  color: rgba(244, 237, 223, 0.78);
  margin: 0.45rem 0 0;
}

.page-about .plan-flow {
  font-size: 0.93rem;
  line-height: 1.85;
  color: rgba(244, 237, 223, 0.8);
  border-left: 2px solid var(--c-jade);
  padding-left: 0.9rem;
  margin: 0 0 1.2rem;
  max-width: 36em;
}

.page-about .plan-cta {
  display: inline-block;
}

/* 下一步 */
.page-about .about-next {
  border-top: 1px solid var(--line-gold);
  padding-top: clamp(1.1rem, 3vw, 1.8rem);
}

.page-about .about-next__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.2rem, 3.6vw, 1.7rem);
  color: var(--c-paper);
  margin: 0 0 1rem;
}

.page-about .about-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.75rem;
}

.page-about .about-next__item {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  border: 1px solid var(--line-soft);
  background: rgba(28, 37, 84, 0.5);
  padding: 0.85rem 1rem;
}

.page-about .about-next__item a {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.02rem;
  color: var(--c-gold-hi);
  text-decoration: none;
}

.page-about .about-next__item a:hover,
.page-about .about-next__item a:focus-visible {
  text-decoration: underline;
}

.page-about .about-next__item span {
  font-size: 0.86rem;
  line-height: 1.7;
  color: var(--c-mist);
}

.page-about .people-card a:hover,
.page-about .people-card a:focus-visible,
.page-about .about-toc__shortcut:hover,
.page-about .about-toc__shortcut:focus-visible {
  text-decoration: underline;
}

@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .craft-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.2rem 1.8rem;
  }

  .page-about .plan-ways {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.2rem;
  }

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

@media (min-width: 1024px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 0.9fr);
    align-items: center;
  }

  .page-about .about-layout {
    grid-template-columns: 13.5rem minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: 6.5rem;
    flex-direction: column;
    gap: 0.15rem;
    overflow: visible;
    border-bottom: 0;
    border-left: 1px solid var(--line-soft);
    padding: 0 0 0 0.9rem;
    max-height: calc(100vh - 8rem);
  }

  .page-about .about-toc .toc__title {
    display: block;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    color: var(--c-mist);
    margin: 0 0 0.6rem;
  }

  .page-about .about-toc .toc__link {
    border: 0;
    border-radius: 0;
    padding: 0.4rem 0.2rem;
    white-space: normal;
    border-left: 2px solid transparent;
    margin-left: -1rem;
    padding-left: 0.9rem;
  }

  .page-about .about-toc .toc__link[aria-current="true"] {
    background: transparent;
    color: var(--c-gold-hi);
    border-left-color: var(--c-gold-hi);
  }

  .page-about .about-toc__shortcut {
    margin-top: 0.8rem;
    align-self: flex-start;
  }

  .page-about .about-cols {
    grid-template-columns: minmax(0, 1fr) minmax(0, 15rem);
    gap: 2.2rem;
  }

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

  .page-about .people-rail {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .people-card {
    flex: 1 1 auto;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .people-rail {
    scroll-behavior: auto;
  }
}