.page-about {
  --rail-w: 210px;
  --sec-gap: clamp(46px, 7vw, 92px);
  --node-bg: rgba(29, 27, 63, 0.78);
  background: var(--ink);
  color: var(--text);
  font-family: var(--font-body);
}

/* ── 面包屑 ────────────────────────────── */
.page-about .about-crumb {
  padding-block: 16px 0;
}

/* ── 首屏 ──────────────────────────────── */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(30px, 5vw, 64px) clamp(42px, 6vw, 78px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(92% 82% at 92% 4%, rgba(33, 230, 193, 0.13), transparent 60%),
    radial-gradient(72% 70% at 4% 98%, rgba(255, 106, 43, 0.09), transparent 62%),
    linear-gradient(165deg, var(--ink) 0%, #0b1726 62%, #0d1430 100%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(
    -58deg,
    rgba(148, 166, 187, 0.055) 0 1px,
    transparent 1px 15px
  );
}

.page-about .about-hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(28px, 4vw, 46px);
  align-items: end;
}

.page-about .about-kicker {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-about h1 {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(40px, 8.4vw, 94px);
  line-height: 0.98;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .h1-accent {
  color: var(--cyan);
  background: linear-gradient(180deg, transparent 74%, rgba(33, 230, 193, 0.24) 74%);
}

.page-about .about-lede {
  margin: 0 0 28px;
  max-width: 34em;
  font-size: clamp(16px, 1.15vw, 18.5px);
  line-height: 1.8;
  color: var(--text);
}

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

.page-about .about-stats li {
  padding: 13px 15px 15px;
  background: rgba(22, 32, 47, 0.74);
  border-top: 2px solid var(--cyan);
}

.page-about .about-stats li:nth-child(2) {
  border-top-color: var(--orange);
}

.page-about .about-stats li:nth-child(3) {
  border-top-color: var(--mist);
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(21px, 2.6vw, 29px);
  line-height: 1.1;
  color: var(--text);
}

.page-about .about-stat-label {
  display: block;
  margin-top: 5px;
  font-size: 12.5px;
  line-height: 1.5;
  letter-spacing: 0.03em;
  color: var(--muted);
}

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

.page-about .about-hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.82) brightness(0.94);
  clip-path: polygon(0 0, calc(100% - 28px) 0, 100% 28px, 100% 100%, 28px 100%, 0 calc(100% - 28px));
}

.page-about .about-hero-caption {
  margin-top: 12px;
  padding-left: 12px;
  border-left: 2px solid var(--line);
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--muted);
}

/* ── 主体两栏 ──────────────────────────── */
.page-about .about-body {
  display: grid;
  gap: var(--sec-gap);
  padding-block: clamp(34px, 5vw, 62px) clamp(50px, 7vw, 96px);
}

.page-about .about-toc .toc-title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .about-toc .toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-toc .toc-link {
  display: block;
  padding: 8px 10px;
  font-size: 13.5px;
  line-height: 1.45;
  color: var(--muted);
  text-decoration: none;
  border-left: 2px solid transparent;
  background: transparent;
  transition: color 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.page-about .about-toc .toc-link:hover,
.page-about .about-toc .toc-link[aria-current] {
  color: var(--text);
  border-left-color: var(--cyan);
  background: rgba(33, 230, 193, 0.08);
}

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

/* ── 章节通用 ──────────────────────────── */
.page-about .about-sec {
  margin-bottom: var(--sec-gap);
  scroll-margin-top: 110px;
}

.page-about .about-sec:last-of-type {
  margin-bottom: 0;
}

.page-about .section-head {
  scroll-margin-top: 110px;
  margin-bottom: 16px;
}

.page-about .about-sec-lede {
  margin: 0 0 28px;
  max-width: 36em;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .about-note {
  display: block;
  margin: 22px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--line);
  max-width: 40em;
}

/* ── 01 团队分工 ───────────────────────── */
.page-about .roster-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.page-about .roster-card {
  position: relative;
  padding: 20px 20px 22px;
  background: linear-gradient(152deg, var(--ink-2) 0%, #131c2b 100%);
  border-left: 3px solid var(--cyan);
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 0 100%);
  transition: background 0.25s ease;
}

.page-about .roster-card:nth-child(2) {
  border-left-color: var(--orange);
}

.page-about .roster-card:nth-child(3) {
  border-left-color: var(--mist);
}

.page-about .roster-card:hover {
  background: linear-gradient(152deg, #1c2738 0%, #141e2c 100%);
}

.page-about .roster-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 10px;
}

.page-about .roster-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 3vw, 34px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .roster-card:nth-child(2) .roster-num {
  color: var(--orange);
}

.page-about .roster-card:nth-child(3) .roster-num {
  color: var(--mist);
}

.page-about .roster-role {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(19px, 1.6vw, 23px);
  letter-spacing: 0.01em;
  color: var(--text);
}

.page-about .roster-desc {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .roster-tag {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

/* ── 02 制作流程 ───────────────────────── */
.page-about .flow-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .flow-item {
  position: relative;
  padding: 24px 22px 26px 26px;
  background: linear-gradient(200deg, #16202f 0%, #111a27 100%);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

.page-about .flow-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: linear-gradient(180deg, var(--cyan) 0%, transparent 92%);
}

.page-about .flow-item:nth-child(2)::before {
  background: linear-gradient(180deg, var(--orange) 0%, transparent 92%);
}

.page-about .flow-item:nth-child(3)::before {
  background: linear-gradient(180deg, var(--mist) 0%, transparent 92%);
}

.page-about .flow-phase {
  display: inline-block;
  padding: 4px 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.16em;
  background: var(--cyan);
  color: var(--ink);
}

.page-about .flow-phase--orange {
  background: var(--orange);
}

.page-about .flow-phase--ghost {
  background: transparent;
  color: var(--mist);
  border: 1px solid var(--mist);
}

.page-about .flow-time {
  margin: 14px 0 8px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--text);
}

.page-about .flow-desc {
  margin: 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.82;
  color: var(--muted);
}

/* ── 03 发展时间轴 ─────────────────────── */
.page-about .about-timeline {
  position: relative;
  margin-top: 26px;
  padding-block: 10px;
}

.page-about .timeline-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.16;
  pointer-events: none;
}

.page-about .timeline-list {
  position: relative;
  z-index: 1;
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .timeline-node {
  padding: 18px 20px 20px;
  background: var(--node-bg);
  border-top: 2px solid var(--cyan);
  clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 0 100%);
}

.page-about .timeline-item:nth-child(even) .timeline-node {
  border-top-color: var(--orange);
}

.page-about .timeline-year {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 3vw, 38px);
  line-height: 1;
  color: var(--orange);
}

.page-about .timeline-item:nth-child(even) .timeline-year {
  color: var(--cyan);
}

.page-about .timeline-label {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--text);
}

.page-about .timeline-text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--muted);
}

/* ── 04 内容标准 ───────────────────────── */
.page-about .standards-grid {
  display: grid;
  gap: 22px;
  margin-bottom: 30px;
}

.page-about .standards-table-wrap {
  overflow-x: auto;
}

.page-about .standards-table {
  width: 100%;
  min-width: 420px;
}

.page-about .standards-table caption {
  padding-bottom: 12px;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .standards-figure {
  margin: 0;
}

.page-about .standards-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.75) brightness(0.95);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 24px), calc(100% - 24px) 100%, 0 100%);
}

.page-about .standard-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .standard-list li {
  display: grid;
  gap: 3px;
  padding: 16px 18px 18px;
  background: rgba(22, 32, 47, 0.62);
  border-left: 3px solid var(--line);
}

.page-about .standard-list li:nth-child(1) {
  border-left-color: var(--cyan);
}

.page-about .standard-list li:nth-child(2) {
  border-left-color: var(--orange);
}

.page-about .standard-list li:nth-child(3) {
  border-left-color: var(--mist);
}

.page-about .standard-key {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--text);
}

.page-about .standard-list p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

/* ── 05 观察员与协作 ───────────────────── */
.page-about .observer-stats {
  list-style: none;
  margin: 0 0 26px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
}

.page-about .observer-stat {
  padding: 20px 18px 22px;
  background: linear-gradient(160deg, rgba(12, 44, 46, 0.9) 0%, rgba(22, 32, 47, 0.9) 100%);
}

.page-about .observer-stat--wide {
  grid-column: 1 / -1;
  background: linear-gradient(160deg, rgba(56, 18, 31, 0.86) 0%, rgba(22, 32, 47, 0.9) 100%);
}

.page-about .observer-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(34px, 5vw, 54px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .observer-stat--wide .observer-num {
  color: var(--orange);
}

.page-about .observer-label {
  display: block;
  margin-top: 8px;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--muted);
}

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

.page-about .partner-item {
  padding: 18px 20px 20px;
  background: var(--ink-2);
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 0 100%);
}

.page-about .partner-item h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.01em;
  color: var(--text);
}

.page-about .partner-item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--muted);
}

/* ── 尾部行动区 ────────────────────────── */
.page-about .about-cta {
  margin-top: var(--sec-gap);
  padding: clamp(26px, 4vw, 44px) clamp(20px, 3.4vw, 40px);
  background:
    radial-gradient(80% 120% at 100% 0%, rgba(33, 230, 193, 0.14), transparent 58%),
    linear-gradient(140deg, var(--indigo) 0%, #101a2c 100%);
  border-top: 2px solid var(--cyan);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

.page-about .about-cta-kicker {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--orange);
}

.page-about .about-cta-title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 3.4vw, 40px);
  line-height: 1.12;
  color: var(--text);
}

.page-about .about-cta-text {
  margin: 0 0 22px;
  max-width: 32em;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-cta-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ── 桌面栅格与粘性侧栏 ────────────────── */
@media (min-width: 560px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 720px) {
  .page-about .roster-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .standards-grid {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
    align-items: start;
    gap: 30px;
  }

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

@media (min-width: 860px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
    gap: clamp(32px, 5vw, 68px);
  }

  .page-about .flow-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 10px;
    align-items: start;
  }

  .page-about .timeline-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 30px 52px;
  }

  .page-about .timeline-list::before {
    content: "";
    position: absolute;
    left: 50%;
    top: 6%;
    bottom: 6%;
    width: 2px;
    transform: translateX(-50%) rotate(2.6deg);
    background: linear-gradient(180deg, transparent 0%, var(--cyan) 14%, var(--orange) 84%, transparent 100%);
    opacity: 0.5;
  }

  .page-about .timeline-item:nth-child(odd) {
    grid-column: 1;
    transform: translateY(-8px);
  }

  .page-about .timeline-item:nth-child(even) {
    grid-column: 2;
    transform: translateY(34px);
  }

  .page-about .timeline-list {
    padding-bottom: 34px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: clamp(38px, 4.6vw, 74px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 104px;
  }

  .page-about .about-rail-scale {
    display: grid;
    margin-top: 26px;
    padding-top: 18px;
    border-top: 1px solid var(--line);
  }

  .page-about .about-rail-scale span {
    position: relative;
    padding: 7px 0 7px 16px;
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.08em;
    color: var(--muted);
  }

  .page-about .about-rail-scale span::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    width: 9px;
    height: 1px;
    background: var(--line);
  }

  .page-about .about-sec-lede {
    font-size: 17px;
  }
}

@media (max-width: 1023px) {
  .page-about .about-toc {
    padding-bottom: 6px;
    border-bottom: 1px solid var(--line-soft);
  }

  .page-about .about-toc .toc-list {
    display: flex;
    flex-wrap: nowrap;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 10px;
    -webkit-overflow-scrolling: touch;
  }

  .page-about .about-toc .toc-list li {
    flex: 0 0 auto;
  }

  .page-about .about-toc .toc-link {
    white-space: nowrap;
    border-left: none;
    border-bottom: 3px solid transparent;
    background: rgba(22, 32, 47, 0.72);
    padding: 9px 14px;
  }

  .page-about .about-toc .toc-link:hover,
  .page-about .about-toc .toc-link[aria-current] {
    border-bottom-color: var(--cyan);
    background: rgba(33, 230, 193, 0.1);
  }
}

@media (max-width: 480px) {
  .page-about .about-hero-figure img {
    clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 18px 100%, 0 calc(100% - 18px));
  }

  .page-about .observer-stats {
    grid-template-columns: 1fr;
  }

  .page-about .about-cta-links .btn {
    flex: 1 1 100%;
    text-align: center;
  }
}