.page-about {
  --about-display: clamp(38px, 7.6vw, 112px);
  --about-lead-size: clamp(17px, 1.1vw + 14px, 21px);
  --about-index-w: 200px;
  --about-gap: clamp(24px, 4vw, 64px);
  background: var(--ink);
  color: var(--snow);
}

.page-about .container {
  width: 100%;
  max-width: var(--w-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-top: clamp(112px, 13vw, 176px);
  padding-bottom: clamp(48px, 6vw, 96px);
  background:
    radial-gradient(120% 90% at 82% 0%, rgba(200, 255, 62, 0.10) 0%, transparent 58%),
    linear-gradient(180deg, var(--field-deep) 0%, var(--ink) 88%);
}

.page-about .about-hero-media {
  position: absolute;
  top: 0;
  right: 0;
  width: 100%;
  height: 100%;
  opacity: 0.14;
  pointer-events: none;
  mask-image: linear-gradient(200deg, #000 0%, transparent 72%);
  -webkit-mask-image: linear-gradient(200deg, #000 0%, transparent 72%);
}

.page-about .about-hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 70% 40%;
  display: block;
}

.page-about .about-hero-inner {
  position: relative;
  z-index: 1;
}

.page-about .about-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mist);
  margin-bottom: clamp(28px, 4vw, 56px);
}

.page-about .about-crumb a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-crumb a:hover,
.page-about .about-crumb a:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
  outline: none;
}

.page-about .about-crumb-sep {
  color: var(--line);
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(28px, 5vw, 64px);
}

.page-about .eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--lime);
  margin: 0 0 18px;
}

.page-about .about-hero-lead h1 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 200;
  font-size: var(--about-display);
  line-height: 0.94;
  letter-spacing: -0.035em;
  color: var(--snow);
  max-width: 15ch;
}

.page-about .about-hero-aside {
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding-top: 4px;
  border-top: 1px solid var(--line);
}

.page-about .about-hero-text {
  margin: 0;
  font-size: var(--about-lead-size);
  line-height: 1.75;
  color: var(--snow-soft);
}

.page-about .about-hero-text--muted {
  font-size: 16px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 6px;
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  padding-block: clamp(56px, 7vw, 112px);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-chapter--alt {
  background: linear-gradient(180deg, var(--field-deep) 0%, var(--ink) 100%);
}

.page-about .about-chapter--pledge {
  background:
    radial-gradient(90% 70% at 10% 0%, rgba(102, 224, 194, 0.08) 0%, transparent 62%),
    var(--ink);
}

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

.page-about .about-chapter-index {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .about-chapter-index .index-no {
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: 0.16em;
  color: var(--lime);
}

.page-about .about-kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: 0.16em;
  color: var(--mist);
  text-transform: uppercase;
}

.page-about .about-chapter-body h2 {
  margin: 0 0 clamp(20px, 3vw, 32px);
  font-family: var(--font-display);
  font-weight: 300;
  font-size: var(--fs-section);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--snow);
  max-width: 20ch;
}

.page-about .about-p {
  margin: 0 0 28px;
  font-size: var(--fs-body);
  line-height: 1.9;
  color: var(--snow-soft);
  max-width: 68ch;
}

.page-about .about-note {
  margin: 28px 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--amber);
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
  max-width: 64ch;
}

.page-about .about-note a {
  color: var(--snow);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-note a:hover,
.page-about .about-note a:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
  outline: none;
}

/* ---------- 指标 ---------- */
.page-about .about-metrics {
  display: grid;
  gap: 2px;
  margin: 8px 0 0;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-metric {
  background: var(--field-deep);
  padding: clamp(20px, 2.6vw, 32px);
}

.page-about .about-metric .data-figure {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(40px, 6vw, 76px);
  line-height: 0.95;
  letter-spacing: -0.02em;
  color: var(--lime);
  transition: transform var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-metric:hover .data-figure {
  transform: translateY(-2px);
  color: var(--cyan);
}

.page-about .about-metric-label {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 四步流程 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: 0 0 36px;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-step {
  padding: 22px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-step-no {
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: 0.2em;
  color: var(--amber);
}

.page-about .about-step h3 {
  margin: 10px 0 8px;
  font-size: 19px;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--snow);
}

.page-about .about-step p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
  max-width: 56ch;
}

.page-about .about-figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--field-board);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 3 / 2;
}

.page-about .about-figure--wide img {
  aspect-ratio: 10 / 7;
}

.page-about .about-figure figcaption {
  padding: 14px 18px;
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: 0.08em;
  line-height: 1.7;
  color: var(--mist);
  border-top: 1px solid var(--line);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 22px;
  position: relative;
  display: grid;
  gap: 28px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  top: 6px;
  bottom: 6px;
  left: 0;
  width: 1px;
  background: var(--line);
}

.page-about .about-tl-item {
  position: relative;
  padding: 2px 0 0 0;
  outline: none;
}

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 8px;
  width: 9px;
  height: 9px;
  background: var(--ink);
  border: 1px solid var(--mist);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-tl-item:hover::before,
.page-about .about-tl-item:focus-visible::before {
  background: var(--lime);
  border-color: var(--lime);
}

.page-about .about-tl-year {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: 0.18em;
  color: var(--lime);
  margin-bottom: 8px;
}

.page-about .about-tl-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 24px;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--snow);
}

.page-about .about-tl-note {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
  max-width: 42ch;
}

/* ---------- 团队色带 ---------- */
.page-about .about-roster {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-role {
  display: grid;
  gap: 4px;
  padding: 20px;
  background: var(--field-board);
  border-left: 3px solid var(--line);
  transition: transform var(--dur) var(--ease), filter var(--dur) var(--ease);
}

.page-about .about-role:hover {
  transform: translateY(-2px);
  filter: brightness(1.12);
}

.page-about .about-role-num {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(34px, 4vw, 54px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--snow);
}

.page-about .about-role-name {
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--snow);
}

.page-about .about-role-desc {
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-role--edit { border-left-color: var(--lime); }
.page-about .about-role--data { border-left-color: var(--cyan); }
.page-about .about-role--ops { border-left-color: var(--amber); }
.page-about .about-role--dev { border-left-color: var(--paper); }
.page-about .about-role--care { border-left-color: var(--mist); }

.page-about .about-role--edit .about-role-num { color: var(--lime); }
.page-about .about-role--data .about-role-num { color: var(--cyan); }
.page-about .about-role--ops .about-role-num { color: var(--amber); }
.page-about .about-role--dev .about-role-num { color: var(--paper); }

/* ---------- 合作生态 ---------- */
.page-about .about-network {
  display: grid;
  gap: 20px;
  margin: 0 0 36px;
}

.page-about .about-net {
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.page-about .about-net .data-figure {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(38px, 5vw, 64px);
  line-height: 0.95;
  letter-spacing: -0.02em;
  color: var(--cyan);
}

.page-about .about-net h3 {
  margin: 10px 0 6px;
  font-size: 17px;
  font-weight: 500;
  color: var(--snow);
}

.page-about .about-net p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 承诺纸面 ---------- */
.page-about .about-pledge {
  padding: clamp(24px, 4vw, 44px);
  color: var(--paper-ink);
  box-shadow: 0 1px 0 rgba(7, 11, 9, 0.4);
}

.page-about .about-pledge-lead {
  margin: 0 0 24px;
  font-size: var(--fs-body);
  line-height: 1.85;
  color: var(--paper-ink);
  max-width: 62ch;
}

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

.page-about .about-pledge-list li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(20, 16, 10, 0.82);
}

.page-about .about-pledge-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 8px;
  height: 1px;
  background: var(--paper-ink);
}

.page-about .about-pledge-list strong {
  font-weight: 600;
  color: var(--paper-ink);
}

.page-about .about-pledge-foot {
  margin: 24px 0 0;
  padding-top: 18px;
  border-top: 1px solid rgba(20, 16, 10, 0.18);
  font-size: 14px;
  line-height: 1.8;
  color: rgba(20, 16, 10, 0.7);
}

.page-about .about-cta {
  margin-top: 32px;
  padding-top: 26px;
  border-top: 1px solid var(--line-soft);
  display: grid;
  gap: 16px;
}

.page-about .about-cta p {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--snow-soft);
}

/* ---------- 渐进显现 ---------- */
.page-about [data-reveal] {
  opacity: 1;
}

@media (prefers-reduced-motion: no-preference) {
  .page-about [data-reveal] {
    opacity: 0.001;
    transform: translateY(18px);
    transition: opacity 520ms var(--ease), transform 520ms var(--ease);
  }

  .page-about [data-reveal].is-revealed {
    opacity: 1;
    transform: none;
  }
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .about-metrics {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .about-network {
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: 1.15fr 0.85fr;
    align-items: start;
  }

  .page-about .about-hero-aside {
    padding-top: 16px;
    gap: 20px;
  }

  .page-about .about-chapter-grid {
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-chapter-index {
    position: sticky;
    top: 120px;
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .page-about .about-chapter-index::after {
    content: "";
    display: block;
    width: 40px;
    height: 1px;
    background: var(--line);
    margin-top: 6px;
  }

  .page-about .about-roster {
    grid-template-columns: 18fr 6fr 4fr 3fr 2fr;
  }

  .page-about .about-role {
    padding: 22px 16px 26px;
    align-content: start;
    min-height: 168px;
  }

  .page-about .about-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0;
    padding-left: 0;
    border-top: 1px solid var(--line);
    padding-top: 28px;
  }

  .page-about .about-timeline::before {
    display: none;
  }

  .page-about .about-tl-item {
    padding: 0 20px 0 0;
  }

  .page-about .about-tl-item::before {
    left: 0;
    top: -34px;
    width: 8px;
    height: 8px;
    border-color: var(--line);
  }

  .page-about .about-tl-note {
    opacity: 0.52;
    transition: opacity var(--dur) var(--ease), color var(--dur) var(--ease);
  }

  .page-about .about-tl-item:hover .about-tl-note,
  .page-about .about-tl-item:focus-visible .about-tl-note {
    opacity: 1;
    color: var(--snow-soft);
  }

  .page-about .about-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 40px;
  }

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

  .page-about .about-cta .about-hero-actions {
    margin-top: 0;
  }

  .page-about .about-hero-media {
    width: 58%;
    height: 100%;
    opacity: 0.3;
  }
}

@media (min-width: 1200px) {
  .page-about {
    --about-index-w: 240px;
  }

  .page-about .about-chapter-body h2 {
    max-width: 22ch;
  }
}
<<<END>>>