.page-about {
  --about-cut: 16px;
  display: block;
  background: var(--ink);
  color: var(--paper);
  overflow-x: hidden;
}

.page-about a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 240, 208, .35);
  transition: border-color var(--ease), color var(--ease);
}

.page-about a:hover {
  border-bottom-color: var(--cyan);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 24px 0 52px;
  background-color: var(--ink);
  background-image:
    repeating-linear-gradient(to right, rgba(36, 74, 94, .55) 0 1px, transparent 1px 88px),
    repeating-linear-gradient(to bottom, rgba(36, 74, 94, .4) 0 1px, transparent 1px 88px);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.page-about .breadcrumb {
  margin-bottom: 22px;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 28px;
}

.page-about .about-hero__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(64px, 17vw, 132px);
  line-height: .78;
  letter-spacing: -.04em;
  color: rgba(43, 240, 208, .18);
  -webkit-text-stroke: 2px rgba(43, 240, 208, .55);
  margin-bottom: 14px;
}

@supports not (-webkit-text-stroke: 1px red) {
  .page-about .about-hero__num {
    color: rgba(43, 240, 208, .3);
  }
}

.page-about .about-hero__eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--cyan);
  margin: 0 0 12px;
  text-transform: uppercase;
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(28px, 6.4vw, 54px);
  line-height: 1.04;
  letter-spacing: -.03em;
  color: var(--paper);
  max-width: 20ch;
}

.page-about .about-hero__lead {
  margin: 18px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
  max-width: 56ch;
}

.page-about .about-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px 30px;
  margin: 26px 0 0;
  padding-top: 18px;
  border-top: 1px dashed var(--line);
}

.page-about .about-hero__meta-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-hero__meta-label {
  font-size: 12px;
  letter-spacing: .07em;
  color: var(--mist);
  margin: 0;
}

.page-about .about-hero__meta-num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 21px;
  font-variant-numeric: tabular-nums;
  color: var(--signal);
}

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

.page-about .about-hero__actions .btn {
  border-bottom: 0;
}

.page-about .about-hero__figure {
  margin: 0;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
  background: var(--panel);
  aspect-ratio: 5 / 4;
  overflow: hidden;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  max-width: 100%;
}

.page-about .about-hero__figure figcaption {
  display: none;
}

/* ---------- 通用图文 ---------- */
.page-about .about-figure {
  margin: 24px 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .about-figure--wide img {
  aspect-ratio: 16 / 9;
}

.page-about .about-figure--tall img {
  aspect-ratio: 14 / 9;
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 主体轨道 ---------- */
.page-about .about-body {
  padding: 32px 0 56px;
}

.page-about .rail-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
}

.page-about .rail {
  background: var(--pine);
  border: 1px solid var(--line);
  padding: 16px 14px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .rail__title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .rail__list {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .rail__list a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 10px;
  font-size: 14px;
  color: var(--mist);
  border: 0;
  border-left: 2px solid transparent;
  transition: color var(--ease), background-color var(--ease), border-color var(--ease);
}

.page-about .rail__list a:hover {
  color: var(--paper);
  border-left-color: var(--cyan);
  background: rgba(43, 240, 208, .08);
}

.page-about .rail__list a[aria-current="true"] {
  color: var(--paper);
  border-left-color: var(--signal);
  background: rgba(255, 106, 42, .12);
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--signal);
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding: 30px 0;
  border-top: 1px solid var(--line);
}

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

.page-about .chapter-head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 16px;
}

.page-about .chapter-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--cyan);
  border: 1px solid var(--line);
  padding: 3px 8px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 6px), calc(100% - 6px) 100%, 0 100%);
}

.page-about .chapter-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 4.2vw, 30px);
  line-height: 1.18;
  letter-spacing: -.02em;
  color: var(--paper);
}

.page-about .about-prose p,
.page-about .about-prose-lead {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
  max-width: 64ch;
}

.page-about .about-prose-lead {
  color: var(--paper);
  font-weight: 500;
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 26px 0 0;
  padding: 0 0 0 4px;
  border-left: 2px solid var(--line);
}

.page-about .about-timeline__item {
  position: relative;
  padding-left: 20px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 20px;
  width: 10px;
  height: 10px;
  background: var(--signal);
  clip-path: polygon(0 0, 100% 0, 100% 60%, 60% 100%, 0 100%);
}

.page-about .tl {
  border-bottom: 1px dashed rgba(36, 74, 94, .9);
}

.page-about .tl__summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 14px 0;
  cursor: pointer;
  list-style: none;
  transition: color var(--ease);
}

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

.page-about .tl__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--cyan);
}

.page-about .tl[open] .tl__summary::after {
  content: "–";
}

.page-about .tl__summary:hover {
  color: var(--cyan);
}

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

.page-about .tl__year {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--signal);
  letter-spacing: .05em;
}

.page-about .tl__title {
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .tl__body {
  padding: 0 0 16px;
}

.page-about .tl__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
  max-width: 60ch;
}

/* ---------- 团队矩阵 ---------- */
.page-about .about-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: 18px;
}

.page-about .role-card {
  background: var(--panel);
  border: 1px solid var(--line);
  padding: 18px 18px 20px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
  transition: border-color var(--ease), background-color var(--ease);
}

.page-about .role-card:hover {
  border-color: var(--cyan);
  background: #12324d;
}

.page-about .role-card__num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--cyan);
  border: 1px solid var(--line);
  padding: 1px 6px;
  margin-bottom: 10px;
}

.page-about .role-card__name {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .role-card__count {
  margin: 4px 0 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--signal);
  letter-spacing: .04em;
}

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

/* ---------- 方法步骤 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
}

.page-about .about-steps li {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 14px;
  padding: 14px 0;
  border-top: 1px dashed var(--line);
}

.page-about .about-steps__num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--cyan);
  padding-top: 3px;
}

.page-about .about-steps p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-steps strong {
  color: var(--paper);
  font-weight: 700;
}

.page-about .about-note {
  margin-top: 24px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan);
  background: rgba(16, 44, 68, .6);
  padding: 16px 18px;
}

.page-about .about-note p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 质量区（浅色） ---------- */
.page-about .about-quality {
  margin: 30px 0;
  padding: 28px 20px 30px;
  background: var(--paper);
  color: var(--void);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 24px), calc(100% - 24px) 100%, 0 100%);
}

.page-about .chapter-head--ink {
  margin-bottom: 10px;
}

.page-about .chapter-num--ink {
  color: var(--pine);
  border-color: rgba(11, 59, 52, .35);
}

.page-about .chapter-title--ink {
  color: var(--void);
}

.page-about .about-quality__lead {
  margin: 0 0 18px;
  font-family: var(--font-serif);
  font-size: 15px;
  line-height: 1.85;
  color: rgba(2, 11, 18, .78);
  max-width: 58ch;
}

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

.page-about .quality-list li {
  position: relative;
  padding-left: 24px;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(2, 11, 18, .76);
}

.page-about .quality-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 10px;
  height: 10px;
  background: var(--signal);
  clip-path: polygon(0 0, 100% 0, 100% 60%, 60% 100%, 0 100%);
}

.page-about .quality-list strong {
  color: var(--void);
  font-weight: 700;
}

.page-about .quality-metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 2px;
  margin-top: 24px;
  border-top: 1px solid rgba(2, 11, 18, .15);
  padding-top: 18px;
}

.page-about .quality-metric .metric__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 24px;
  font-variant-numeric: tabular-nums;
  color: var(--pine);
  letter-spacing: -.01em;
}

.page-about .quality-metric .metric__label {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  line-height: 1.5;
  color: rgba(2, 11, 18, .6);
}

/* ---------- 生态 ---------- */
.page-about .about-eco {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .eco-card {
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan);
  background: rgba(16, 44, 68, .55);
  padding: 16px 18px;
}

.page-about .eco-card--signal {
  border-left-color: var(--signal);
}

.page-about .eco-card--violet {
  border-left-color: var(--violet);
}

.page-about .eco-card__title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .eco-card__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-eco__more {
  margin: 18px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 结尾 ---------- */
.page-about .about-cta {
  margin-top: 30px;
  padding: 26px 20px 30px;
  background: var(--pine);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

.page-about .chapter-num--signal {
  color: var(--signal);
  border-color: rgba(255, 106, 42, .5);
}

.page-about .about-cta .chapter-title--ink {
  color: var(--paper);
}

.page-about .about-cta__lead {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
  max-width: 56ch;
}

.page-about .cta-contact {
  display: grid;
  gap: 12px;
  margin: 0 0 16px;
  padding: 16px 0;
  border-top: 1px dashed var(--line);
  border-bottom: 1px dashed var(--line);
}

.page-about .cta-contact__row {
  display: grid;
  gap: 3px;
}

.page-about .cta-contact__label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--cyan);
}

.page-about .cta-contact__value {
  margin: 0;
  font-size: 15px;
  line-height: 1.6;
  color: var(--paper);
  overflow-wrap: anywhere;
}

.page-about .cta-contact__value--mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .02em;
}

.page-about .about-cta__hint {
  margin: 0 0 20px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-cta__actions .btn {
  border-bottom: 0;
}

/* ---------- 断点 ---------- */
@media (min-width: 620px) {
  .page-about .about-hero {
    padding: 28px 0 64px;
  }

  .page-about .about-hero__lead {
    font-size: 16px;
  }

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

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

  .page-about .about-quality {
    padding: 36px 34px 38px;
  }

  .page-about .quality-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px 28px;
  }

  .page-about .about-cta {
    padding: 34px 34px 38px;
  }

  .page-about .cta-contact {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px 28px;
  }

  .page-about .cta-contact__row:last-child {
    grid-column: 1 / -1;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1fr) 300px;
    align-items: start;
    gap: 40px;
  }

  .page-about .about-hero__figure {
    aspect-ratio: 3 / 4;
  }

  .page-about .about-hero__figure figcaption {
    display: block;
  }

  .page-about .about-prose p,
  .page-about .about-prose-lead {
    font-size: 16px;
  }
}

@media (min-width: 1024px) {
  .page-about .rail-layout {
    grid-template-columns: var(--rail) minmax(0, 1fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .rail {
    position: sticky;
    top: calc(var(--header-h) + var(--track-h) + 18px);
  }

  .page-about .about-chapter {
    padding: 38px 0;
  }

  .page-about .about-body {
    padding: 44px 0 72px;
  }

  .page-about .about-quality {
    padding: 42px 44px 44px;
    margin: 38px 0;
  }

  .page-about .about-cta {
    padding: 38px 44px 42px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .role-card,
  .page-about .rail__list a,
  .page-about .tl__summary,
  .page-about a {
    transition: none;
  }
}
<<<END>>>