.page-about {
  --about-paper-shadow: 6px 6px 0 rgba(10, 13, 17, .22);
  --about-tint-ink: #12171E;
  background: var(--ink-900);
  color: var(--text-main);
  font-family: var(--font-body);
  line-height: 1.75;
}

.page-about a:focus-visible,
.page-about summary:focus-visible,
.page-about .btn:focus-visible {
  outline: 2px solid var(--cyan-400);
  outline-offset: 2px;
}

/* 面包屑 */
.page-about .about-crumbs {
  padding-top: 18px;
}

.page-about .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
}

.page-about .breadcrumb-item {
  display: inline-flex;
  align-items: center;
}

.page-about .breadcrumb-sep {
  color: var(--gold-500);
}

.page-about .breadcrumb-link {
  color: var(--mist-cyan);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast), border-color var(--t-fast);
}

.page-about .breadcrumb-link:hover,
.page-about .breadcrumb-link:focus-visible {
  color: var(--cyan-400);
  border-bottom-color: var(--cyan-400);
}

.page-about .breadcrumb-current {
  color: var(--gold-200);
}

/* §01 首屏 */
.page-about .about-hero {
  padding: 30px 0 60px;
  border-bottom: 2px solid var(--line-gold);
  background-image: radial-gradient(rgba(200, 162, 74, .11) 1px, transparent 1px);
  background-size: 24px 24px;
  background-position: -1px -1px;
}

.page-about .about-hero-grid {
  display: grid;
  gap: 34px;
  align-items: start;
}

.page-about .about-eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--gold-500);
}

.page-about .about-title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(29px, 7vw, 48px);
  line-height: 1.22;
  letter-spacing: .05em;
  color: var(--paper-100);
}

.page-about .about-lede {
  margin: 0 0 26px;
  max-width: 34em;
  font-size: 17px;
  color: var(--text-soft);
}

.page-about .about-mini-title {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--mist-cyan);
}

.page-about .about-simple {
  list-style: none;
  margin: 0 0 26px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-simple li {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 10px;
  align-items: start;
  padding-left: 12px;
  border-left: 2px solid var(--line-gold);
  font-size: 15px;
  color: var(--text-soft);
  transition: border-color var(--t-fast);
}

.page-about .about-simple li:hover {
  border-left-color: var(--gold-200);
}

.page-about .about-simple .mono {
  color: var(--gold-500);
  font-size: 13px;
  line-height: 1.8;
}

.page-about .about-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin: 0;
  padding-top: 16px;
  border-top: 1px solid var(--line-soft);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--mist-cyan);
}

.page-about .about-hero-media {
  margin: 0;
  border: 2px solid var(--gold-500);
  box-shadow: var(--shadow-hard);
  background: var(--ink-750);
}

.page-about .about-hero-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .media-cap {
  padding: 10px 12px;
  font-size: 12px;
  line-height: 1.65;
  color: var(--mist-cyan);
  border-top: 1px solid var(--line-soft);
}

/* 章节索引 + 正文 */
.page-about .about-layout {
  display: grid;
  gap: 10px;
  padding: 44px 0 0;
}

.page-about .about-index-title {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--mist-cyan);
}

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

.page-about .about-index-list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
  padding: 7px 12px;
  border: 2px solid var(--line-gold);
  background: var(--ink-750);
  color: var(--gold-200);
  text-decoration: none;
  font-size: 13px;
  transition: border-color var(--t-fast), color var(--t-fast), background var(--t-fast);
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  border-color: var(--cyan-400);
  color: var(--cyan-400);
  background: rgba(53, 224, 210, .08);
}

.page-about .about-index-list .mono {
  font-size: 12px;
  color: var(--gold-500);
}

.page-about .about-chapter {
  position: relative;
  padding: 14px 0 60px;
}

.page-about .about-chapter + .about-chapter {
  margin-top: 10px;
}

.page-about .about-chapter--tinted {
  padding: 26px 20px 48px;
  margin: 20px -20px 0;
}

.page-about .about-chapter--wine {
  background: var(--wine-700);
}

.page-about .about-chapter--indigo {
  background: var(--indigo-800);
}

.page-about .about-chapter--ink {
  background: var(--about-tint-ink);
  border-top: 2px solid var(--line-gold);
}

.page-about .band {
  display: block;
  width: 100%;
  height: 6px;
  margin-bottom: 24px;
}

.page-about .chapter-head {
  margin-bottom: 20px;
}

.page-about .chapter-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 40px;
  line-height: 1;
  letter-spacing: -.02em;
  color: rgba(200, 162, 74, .55);
}

.page-about .chapter-title {
  margin: 12px 0 8px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 23px;
  line-height: 1.38;
  letter-spacing: .05em;
  color: var(--paper-100);
}

.page-about .chapter-kicker {
  margin: 0;
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--mist-cyan);
}

.page-about .about-quote {
  margin: 0 0 26px;
  padding: 4px 0 4px 16px;
  border-left: 6px solid var(--gold-500);
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: .08em;
  color: var(--gold-200);
}

/* §02 准则 */
.page-about .about-principles {
  display: grid;
  gap: 20px;
}

.page-about .about-principle {
  position: relative;
  padding: 22px 18px 20px 24px;
  background: var(--ink-750);
  border: 2px solid var(--line-gold);
  box-shadow: var(--shadow-hard);
}

.page-about .about-principle::before {
  content: "";
  position: absolute;
  left: -2px;
  top: -2px;
  bottom: -2px;
  width: 2px;
  background: var(--gold-500);
  transition: width var(--t-fast), background var(--t-fast);
}

.page-about .about-principle:hover::before,
.page-about .about-principle:focus-within::before {
  width: 7px;
  background: var(--gold-200);
}

.page-about .about-principle-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 14px;
}

.page-about .about-principle-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--amber-500);
}

.page-about .about-principle h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 19px;
  line-height: 1.45;
  letter-spacing: .04em;
  color: var(--paper-100);
}

.page-about .about-points {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-points li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  color: var(--text-soft);
}

.page-about .about-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .74em;
  width: 7px;
  height: 2px;
  background: var(--gold-500);
}

.page-about .about-fold {
  border-top: 1px dashed var(--line-gold);
  padding-top: 12px;
}

.page-about .about-fold summary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  list-style: none;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--cyan-400);
}

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

.page-about .about-fold summary::before {
  content: "+";
  display: inline-block;
  width: 16px;
  text-align: center;
  line-height: 14px;
  font-size: 12px;
  border: 1px solid var(--cyan-400);
}

.page-about .about-fold[open] summary::before {
  content: "−";
}

.page-about .about-fold .fold-body {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist-cyan);
}

/* §03 团队 */
.page-about .about-team {
  margin: 0;
  display: grid;
  border-top: 2px solid var(--line-gold);
}

.page-about .about-team-row {
  display: grid;
  gap: 6px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-team-row dt {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-team-num {
  font-family: var(--font-mono);
  font-size: 34px;
  line-height: 1;
  color: var(--gold-500);
}

.page-about .about-team-role {
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: .06em;
  color: var(--paper-100);
}

.page-about .about-team-row dd {
  margin: 0;
  max-width: 40em;
  font-size: 15px;
  color: var(--text-soft);
}

.page-about .about-after {
  margin: 24px 0 0;
  padding-top: 18px;
  border-top: 1px dashed var(--line-gold);
  font-size: 15px;
  color: var(--text-soft);
}

/* §04 版本历程 */
.page-about .about-figure {
  margin: 0 0 24px;
  border: 2px solid var(--gold-500);
  background: var(--ink-900);
  box-shadow: var(--shadow-hard);
}

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

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 20px;
  border-left: 2px solid var(--line-gold);
  display: grid;
  gap: 14px;
}

.page-about .about-tl {
  position: relative;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 14px;
  width: 9px;
  height: 9px;
  background: var(--indigo-800);
  border: 2px solid var(--gold-500);
}

.page-about .about-tl-summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 10px 0;
  list-style: none;
  cursor: pointer;
}

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

.page-about .about-tl-year {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: .06em;
  color: var(--amber-500);
}

.page-about .about-tl-ver {
  font-family: var(--font-mono);
  font-size: 12px;
  padding: 2px 7px;
  border: 1px solid var(--line-gold);
  color: var(--gold-200);
}

.page-about .about-tl-title {
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: .04em;
  color: var(--paper-100);
  transition: color var(--t-fast);
}

.page-about .about-tl[open] .about-tl-title,
.page-about .about-tl-summary:hover .about-tl-title {
  color: var(--gold-200);
}

.page-about .about-tl-body {
  display: grid;
  gap: 10px;
  padding: 2px 0 12px;
}

.page-about .about-tl-body p {
  margin: 0;
  font-size: 15px;
  color: var(--text-soft);
}

.page-about .about-tl-label {
  display: block;
  margin-bottom: 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--mist-cyan);
}

/* §05 流程 */
.page-about .about-flow {
  display: grid;
  gap: 26px;
}

.page-about .about-flow-media {
  margin-bottom: 0;
}

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

.page-about .about-steps > li {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 14px;
  padding: 16px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-steps > li:last-child {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-step-num {
  font-family: var(--font-mono);
  font-size: 22px;
  line-height: 1.2;
  color: var(--gold-500);
}

.page-about .about-step-body h3 {
  margin: 0 0 4px;
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: .05em;
  color: var(--paper-100);
}

.page-about .about-step-owner {
  margin: 0 0 6px;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--amber-500);
}

.page-about .about-step-body p:last-child {
  margin: 0;
  font-size: 15px;
  color: var(--text-soft);
}

/* §06 服务承诺 */
.page-about .about-service {
  margin-top: 70px;
  background: var(--paper-100);
  color: var(--ink-900);
  border-top: 6px solid var(--gold-500);
  border-bottom: 6px solid var(--gold-500);
}

.page-about .about-service-inner {
  padding: 40px 0 52px;
}

.page-about .about-eyebrow--dark {
  color: #7d6220;
}

.page-about .about-service-title {
  margin: 10px 0 24px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 23px;
  line-height: 1.4;
  letter-spacing: .05em;
  color: var(--ink-900);
}

.page-about .about-service-grid {
  display: grid;
  gap: 26px;
}

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

.page-about .about-service-list li {
  padding-left: 16px;
  border-left: 3px solid var(--gold-500);
  font-size: 15px;
  color: var(--ink-900);
}

.page-about .about-service-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-content: start;
}

.page-about .about-service-actions .btn {
  background: var(--ink-900);
  color: var(--gold-200);
  border: 2px solid var(--ink-900);
  box-shadow: var(--about-paper-shadow);
  transition: background var(--t-fast), color var(--t-fast), border-color var(--t-fast);
}

.page-about .about-service-actions .btn:hover,
.page-about .about-service-actions .btn:focus-visible {
  background: var(--wine-700);
  border-color: var(--wine-700);
  color: var(--paper-100);
}

.page-about .about-service-actions .btn--ghost {
  background: transparent;
  color: var(--ink-900);
  border-color: var(--ink-900);
  box-shadow: none;
}

.page-about .about-service-actions .btn--ghost:hover,
.page-about .about-service-actions .btn--ghost:focus-visible {
  background: var(--ink-900);
  color: var(--gold-200);
}

/* 平板及以上 */
@media (min-width: 720px) {
  .page-about .about-crumbs {
    padding-top: 22px;
  }

  .page-about .about-hero {
    padding: 38px 0 72px;
  }

  .page-about .chapter-head {
    display: grid;
    grid-template-columns: 96px minmax(0, 1fr);
    column-gap: 20px;
    align-items: start;
  }

  .page-about .chapter-num {
    grid-row: 1 / span 2;
    font-size: 64px;
  }

  .page-about .chapter-title {
    margin-top: 2px;
    font-size: 26px;
  }

  .page-about .about-team-row {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: 24px;
    align-items: start;
  }

  .page-about .about-service-title {
    font-size: 26px;
  }
}

/* 桌面 */
@media (min-width: 860px) {
  .page-about .about-flow {
    grid-template-columns: minmax(0, .8fr) minmax(0, 1.2fr);
    gap: 32px;
    align-items: start;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    gap: 48px;
  }

  .page-about .about-hero-media {
    margin-right: calc(-1 * var(--edge));
  }

  .page-about .about-layout {
    grid-template-columns: 200px minmax(0, 1fr);
    column-gap: 56px;
    padding-top: 66px;
  }

  .page-about .about-index {
    position: sticky;
    top: 100px;
    align-self: start;
    padding-bottom: 40px;
  }

  .page-about .about-index-list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-index-list a {
    display: flex;
    padding: 9px 0 9px 14px;
    border: 0;
    border-left: 2px solid var(--line-soft);
    background: none;
    color: var(--text-soft);
  }

  .page-about .about-index-list a:hover,
  .page-about .about-index-list a:focus-visible {
    border-left-color: var(--cyan-400);
    background: none;
    color: var(--cyan-400);
  }

  .page-about .about-chapter--tinted {
    padding: 34px 36px 52px;
    margin-left: -36px;
    margin-right: -36px;
  }

  .page-about .about-principle {
    padding: 26px 26px 22px 30px;
  }

  .page-about .about-principle h3 {
    font-size: 20px;
  }

  .page-about .about-service {
    margin-top: 96px;
  }

  .page-about .about-service-grid {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, .75fr);
    column-gap: 48px;
  }

  .page-about .about-service-actions {
    justify-content: flex-start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 0.01ms !important;
  }
}
<<<END>>>