.page-about {
  --ab-grid-line: rgba(18, 35, 63, .07);
  --ab-hair: rgba(18, 35, 63, .12);
  --ab-sand-line: rgba(228, 178, 92, .55);
  --ab-ink-soft: #3B4657;
  background: var(--by-cream);
  color: var(--by-ink);
  padding-top: var(--hdr-h);
  font-family: var(--font-body);
}

.page-about .img-frame {
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--by-mist);
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 34px 0 44px;
  border-bottom: 1px solid var(--ab-hair);
  isolation: isolate;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(var(--ab-grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--ab-grid-line) 1px, transparent 1px);
  background-size: 54px 54px;
  -webkit-mask-image: linear-gradient(180deg, #000 0%, rgba(0, 0, 0, .45) 58%, transparent 100%);
  mask-image: linear-gradient(180deg, #000 0%, rgba(0, 0, 0, .45) 58%, transparent 100%);
}

.page-about .about-hero .breadcrumb {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
}

.page-about .hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 20px 0 0;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--by-slate);
}

.page-about .hero-eyebrow::before {
  content: "";
  display: block;
  width: 34px;
  height: 2px;
  background: var(--by-red);
}

.page-about .hero-title {
  margin: 16px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(31px, 8.2vw, 80px);
  line-height: 1.05;
  letter-spacing: -.02em;
  color: var(--by-navy);
}

.page-about .hero-title em {
  font-style: normal;
  color: var(--by-red);
}

.page-about .hero-lead {
  margin: 18px 0 0;
  max-width: 60ch;
  font-size: 16px;
  line-height: 1.82;
  color: var(--ab-ink-soft);
}

.page-about .hero-stats {
  list-style: none;
  margin: 28px 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--ab-hair);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 16px;
}

.page-about .stat {
  display: flex;
  flex-direction: column;
  gap: 5px;
  min-width: 0;
}

.page-about .stat-num {
  width: fit-content;
  padding: 0 3px;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(25px, 6.2vw, 34px);
  line-height: 1.1;
  color: var(--by-navy);
  background: linear-gradient(180deg, transparent 64%, rgba(228, 178, 92, .55) 64%);
}

.page-about .stat-label {
  font-size: 13px;
  line-height: 1.55;
  color: var(--by-slate);
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

/* ---------- 章节索引 ---------- */
.page-about .about-index {
  position: sticky;
  top: var(--hdr-h);
  z-index: 25;
  background: rgba(247, 241, 230, .94);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--ab-hair);
}

.page-about .about-index-inner {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 10px;
  padding-bottom: 10px;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-index-inner::-webkit-scrollbar {
  display: none;
}

.page-about .index-label {
  flex: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--by-slate);
}

.page-about .index-list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .index-pill {
  display: inline-block;
  flex: none;
  padding: 7px 14px;
  border: 1px solid rgba(18, 35, 63, .16);
  border-radius: var(--r-pill);
  background: var(--by-paper);
  color: var(--by-navy);
  font-size: 13px;
  line-height: 1.4;
  white-space: nowrap;
  text-decoration: none;
  transition: border-color .24s var(--ease), color .24s var(--ease);
}

.page-about .index-pill:hover,
.page-about .index-pill:focus-visible {
  border-color: var(--by-red);
  color: var(--by-red);
}

/* ---------- 通用章节骨架 ---------- */
.page-about .about-section {
  padding: 46px 0;
}

.page-about .sec-head {
  max-width: 720px;
  margin-bottom: 26px;
}

.page-about .sec-num {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--by-red);
}

.page-about .sec-num::after {
  content: "";
  display: block;
  width: 52px;
  height: 2px;
  background: var(--by-sand);
}

.page-about .sec-title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(25px, 5.4vw, 42px);
  line-height: 1.14;
  letter-spacing: -.01em;
  color: var(--by-navy);
}

.page-about .sec-sub {
  margin: 12px 0 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--ab-ink-soft);
}

.page-about .prose p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.8;
}

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

/* ---------- 01 团队构成 ---------- */
.page-about .overview-grid {
  display: grid;
  gap: 24px;
}

.page-about .overview-figure {
  border: 1px solid var(--ab-hair);
}

.page-about .roster {
  display: grid;
  gap: 22px;
  margin-top: 34px;
  padding-top: 26px;
  border-top: 1px solid var(--ab-hair);
}

.page-about .roster-figure {
  border: 1px solid var(--ab-hair);
}

.page-about .roster-title {
  margin: 0 0 14px;
  font-size: 19px;
  font-weight: 700;
  color: var(--by-navy);
}

.page-about .roster-cards {
  display: flex;
  gap: 14px;
  margin: 0;
  padding: 0 0 10px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scrollbar-width: none;
}

.page-about .roster-cards::-webkit-scrollbar {
  display: none;
}

.page-about .role-card {
  flex: 0 0 82%;
  scroll-snap-align: start;
  min-width: 0;
  padding: 18px 18px 20px;
  border-radius: var(--r-lg);
  border-top: 3px solid var(--by-sand);
  background: var(--by-mist);
}

.page-about .role-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.page-about .role-name {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  color: var(--by-navy);
}

.page-about .role-count {
  font-weight: 700;
  font-size: 24px;
  color: var(--by-red);
  line-height: 1;
}

.page-about .role-count small {
  margin-left: 2px;
  font-size: 12px;
  color: var(--by-navy);
}

.page-about .role-body {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--by-ink);
}

.page-about .roster-cta {
  margin: 14px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--ab-ink-soft);
}

.page-about .roster-cta a {
  color: var(--by-red);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 02 协作流程 ---------- */
.page-about .flow-band {
  position: relative;
  background: linear-gradient(158deg, var(--by-navy) 0%, var(--by-night) 100%);
  color: var(--by-cream);
}

.page-about .flow-band::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(228, 178, 92, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(228, 178, 92, .07) 1px, transparent 1px);
  background-size: 64px 64px;
}

.page-about .flow-band .shell {
  position: relative;
  z-index: 1;
}

.page-about .flow-band .sec-num {
  color: var(--by-sand);
}

.page-about .flow-band .sec-title {
  color: var(--by-cream);
}

.page-about .flow-band .sec-sub {
  color: rgba(247, 241, 230, .82);
}

.page-about .flow-figure {
  border: 1px solid rgba(228, 178, 92, .3);
}

.page-about .flow-list {
  display: flex;
  gap: 14px;
  margin: 26px 0 0;
  padding: 0 0 10px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scrollbar-width: none;
}

.page-about .flow-list::-webkit-scrollbar {
  display: none;
}

.page-about .flow-step {
  flex: 0 0 76%;
  scroll-snap-align: start;
  min-width: 0;
  padding: 18px 18px 20px;
  border: 1px solid rgba(228, 178, 92, .3);
  border-radius: var(--r-lg);
  background: rgba(255, 253, 248, .05);
}

.page-about .step-num {
  display: block;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--by-sand);
}

.page-about .step-name {
  margin: 8px 0 0;
  font-size: 17px;
  font-weight: 700;
  color: var(--by-cream);
}

.page-about .step-out {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(247, 241, 230, .8);
}

.page-about .flow-note {
  margin: 20px 0 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .04em;
  line-height: 1.8;
  color: var(--by-sand);
}

/* ---------- 03 做事方式 ---------- */
.page-about .rules-grid {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .rule-card {
  position: relative;
  padding: 20px 20px 22px;
  border: 1px solid rgba(18, 35, 63, .09);
  border-radius: var(--r-lg);
  background: var(--by-paper);
  box-shadow: var(--shadow-soft);
}

.page-about .rule-index {
  display: inline-block;
  padding: 2px 8px;
  border: 1px solid var(--ab-sand-line);
  border-radius: var(--r-sm);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--by-red);
}

.page-about .rule-title {
  margin: 12px 0 0;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--by-navy);
}

.page-about .rule-body {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--ab-ink-soft);
}

.page-about .data-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  margin: 28px 0 0;
  padding: 14px 0;
  list-style: none;
  border-top: 1px solid var(--ab-hair);
  border-bottom: 1px solid var(--ab-hair);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--by-slate);
}

/* ---------- 04 成长阶段 ---------- */
.page-about .timeline {
  position: relative;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 10px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--by-sand), rgba(226, 58, 46, .6) 55%, rgba(18, 35, 63, .15));
}

.page-about .stage {
  position: relative;
  margin: 0 0 16px 34px;
  padding: 18px 20px 20px;
  border: 1px solid rgba(18, 35, 63, .09);
  border-radius: var(--r-lg);
  background: var(--by-paper);
}

.page-about .stage:last-child {
  margin-bottom: 0;
}

.page-about .stage::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 24px;
  width: 14px;
  height: 14px;
  border: 3px solid var(--by-red);
  border-radius: 50%;
  background: var(--by-cream);
  box-shadow: 0 0 0 3px var(--by-cream);
}

.page-about .stage-label {
  margin: 0;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--by-red);
}

.page-about .stage-title {
  margin: 8px 0 0;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--by-navy);
}

.page-about .stage-body {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--ab-ink-soft);
}

/* ---------- 05 协作网络 ---------- */
.page-about .network-grid {
  display: grid;
  gap: 24px;
}

.page-about .partner-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .chip {
  padding: 6px 14px;
  border: 1px solid rgba(18, 35, 63, .14);
  border-radius: var(--r-pill);
  background: var(--by-mist);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--by-navy);
}

.page-about .region-cards {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .region-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  border-left: 3px solid var(--by-sand);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  background: var(--by-paper);
  box-shadow: var(--shadow-soft);
}

.page-about .region-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--by-navy);
}

.page-about .region-role {
  font-size: 14px;
  line-height: 1.7;
  color: var(--by-slate);
}

/* ---------- 06 下一步 ---------- */
.page-about .next-steps {
  background: linear-gradient(132deg, var(--by-orange) 0%, var(--by-red-deep) 100%);
  color: var(--by-paper);
  padding-bottom: 52px;
}

.page-about .next-index {
  margin: 0;
  font-size: 12px;
  letter-spacing: .14em;
  color: rgba(255, 253, 248, .82);
}

.page-about .next-title {
  margin: 14px 0 0;
  max-width: 22ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(26px, 5.6vw, 46px);
  line-height: 1.12;
  letter-spacing: -.01em;
  color: var(--by-paper);
}

.page-about .next-lead {
  margin: 16px 0 0;
  max-width: 58ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(255, 253, 248, .9);
}

.page-about .next-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 24px;
  border: 1.5px solid transparent;
  border-radius: var(--r-pill);
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: transform .24s var(--ease), background .24s var(--ease);
}

.page-about .cta-btn--solid {
  background: var(--by-paper);
  color: var(--by-red-deep);
}

.page-about .cta-btn--line {
  border-color: rgba(255, 253, 248, .72);
  color: var(--by-paper);
}

.page-about .cta-btn:hover,
.page-about .cta-btn:focus-visible {
  transform: translateY(-2px);
}

.page-about .next-links {
  display: grid;
  gap: 8px;
  margin: 26px 0 0;
  padding: 18px 0 0;
  list-style: none;
  border-top: 1px solid rgba(255, 253, 248, .3);
}

.page-about .next-links a {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--by-paper);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 断点 ---------- */
@media (min-width: 760px) {
  .page-about .about-hero {
    padding: 44px 0 56px;
  }

  .page-about .hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px 24px;
  }

  .page-about .about-section {
    padding: 72px 0;
  }

  .page-about .sec-head {
    margin-bottom: 34px;
  }

  .page-about .rules-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .flow-step {
    flex: 0 0 44%;
  }

  .page-about .role-card {
    flex: 0 0 58%;
  }

  .page-about .next-links {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px 24px;
  }
}

@media (min-width: 900px) {
  .page-about .overview-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .roster {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 44px;
    align-items: center;
    margin-top: 44px;
    padding-top: 34px;
  }

  .page-about .roster-cards {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: 14px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .role-card {
    flex: none;
  }

  .page-about .flow-list {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .flow-step {
    flex: none;
  }

  .page-about .timeline::before {
    left: 50%;
    margin-left: -1px;
    top: 14px;
    bottom: 14px;
  }

  .page-about .stage {
    width: calc(50% - 46px);
    margin-left: 0;
    margin-bottom: 22px;
  }

  .page-about .stage:nth-child(odd) {
    margin-right: auto;
  }

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

  .page-about .stage::before {
    left: auto;
    right: -53px;
    top: 26px;
  }

  .page-about .stage:nth-child(even)::before {
    right: auto;
    left: -53px;
  }

  .page-about .network-grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .next-title {
    max-width: 26ch;
  }

  .page-about .next-links {
    margin-top: 34px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-section {
    padding: 92px 0;
  }

  .page-about .about-hero {
    padding: 56px 0 68px;
  }

  .page-about .hero-lead {
    font-size: 17px;
  }
}
<<<END>>>