.page-about {
  --about-cut: 18px;
  background: var(--mist);
  color: var(--graphite);
  font-family: var(--sans);
  overflow-x: hidden;
}

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding: clamp(1.25rem, 4vw, 2.25rem) 0 clamp(2.5rem, 6vw, 4.5rem);
  background:
    radial-gradient(120% 95% at 88% 0%, rgba(18, 46, 74, 0.95), transparent 62%),
    var(--ink);
  color: var(--mist);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: clamp(0.6rem, 2vw, 1.4rem);
  border: 1px solid var(--line-gold);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 6px;
  background: repeating-linear-gradient(to bottom, var(--gold) 0 1px, transparent 1px 26px);
  opacity: 0.55;
  pointer-events: none;
}

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

.page-about .about-breadcrumb {
  margin-bottom: clamp(1.25rem, 3.5vw, 2.25rem);
}

.page-about .about-breadcrumb .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-breadcrumb .breadcrumb-link {
  color: rgba(245, 242, 234, 0.72);
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

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

.page-about .about-breadcrumb .breadcrumb-link[aria-current="page"] {
  color: var(--mist);
}

.page-about .about-breadcrumb .breadcrumb-sep {
  color: rgba(245, 242, 234, 0.34);
  font-size: 0.8125rem;
}

.page-about .about-eyebrow {
  margin: 0 0 0.9rem;
  font-size: 0.6875rem;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .about-hero-title {
  margin: 0 0 1.25rem;
  font-family: var(--serif);
  font-weight: 300;
  font-size: clamp(2.125rem, 8vw, 5.25rem);
  line-height: 1.04;
  letter-spacing: -0.015em;
  color: var(--mist);
}

.page-about .about-hero-lede {
  max-width: 54ch;
  margin: 0 0 clamp(1.5rem, 4vw, 2.5rem);
  font-size: clamp(0.9375rem, 1.6vw, 1.0625rem);
  line-height: 1.85;
  color: rgba(245, 242, 234, 0.82);
}

.page-about .about-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 0.65rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.6875rem;
  letter-spacing: 0.09em;
  color: rgba(245, 242, 234, 0.68);
}

.page-about .about-hero-meta li {
  padding: 0.4rem 0.8rem;
  border: 1px solid rgba(201, 162, 74, 0.34);
  background: rgba(18, 46, 74, 0.55);
  clip-path: polygon(0 0, calc(100% - 9px) 0, 100% 9px, 100% 100%, 0 100%);
}

/* ---------- 章节公共 ---------- */
.page-about .about-section {
  padding: clamp(2.5rem, 7vw, 5rem) 0;
}

.page-about .about-origin,
.page-about .about-team,
.page-about .about-promise {
  background: var(--mist);
}

.page-about .about-timeline,
.page-about .about-quality {
  background: var(--paper);
}

.page-about .about-coverage {
  background:
    linear-gradient(180deg, rgba(8, 24, 42, 0.96), var(--ink));
  color: var(--mist);
}

.page-about .about-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: end;
  gap: 0.6rem 1rem;
  padding-bottom: 0.85rem;
  margin-bottom: clamp(1.5rem, 4vw, 2.75rem);
  border-bottom: 1px solid var(--line-ink);
}

.page-about .about-index {
  font-family: var(--mono);
  font-size: clamp(1.5rem, 4.5vw, 2.5rem);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.page-about .about-kicker {
  margin: 0 0 0.35rem;
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--jade);
}

.page-about .about-title {
  margin: 0;
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(1.5rem, 4vw, 2.375rem);
  line-height: 1.26;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-coverage .about-head {
  border-bottom-color: var(--line-gold);
}

.page-about .about-coverage .about-title {
  color: var(--mist);
}

.page-about .about-coverage .about-kicker {
  color: var(--celadon);
}

.page-about .about-link {
  display: inline-block;
  color: var(--ink);
  font-size: 0.875rem;
  letter-spacing: 0.03em;
  text-decoration: none;
  padding-bottom: 2px;
  background-image: linear-gradient(var(--gold), var(--gold));
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0% 1px;
  transition: background-size 0.18s var(--ease), color 0.18s var(--ease);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  background-size: 100% 1px;
  color: var(--navy);
}

.page-about .about-coverage .about-link {
  color: var(--celadon);
}

.page-about .about-coverage .about-link:hover,
.page-about .about-coverage .about-link:focus-visible {
  color: var(--gold);
}

/* ---------- 01 品牌起点 ---------- */
.page-about .origin-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 5vw, 3.5rem);
}

.page-about .origin-lede {
  margin: 0 0 clamp(1.25rem, 3vw, 1.85rem);
  max-width: 56ch;
  font-size: clamp(0.9375rem, 1.5vw, 1.0625rem);
  line-height: 1.8;
  color: var(--graphite);
}

.page-about .origin-lines {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1.15rem;
}

.page-about .origin-line {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.2rem 1rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--line-ink);
}

.page-about .origin-num {
  grid-row: span 2;
  padding-top: 0.2rem;
  font-size: 0.875rem;
  letter-spacing: 0.08em;
  color: var(--gold);
}

.page-about .origin-line h3 {
  margin: 0;
  font-family: var(--serif);
  font-weight: 500;
  font-size: 1.0625rem;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.page-about .origin-line p {
  margin: 0.3rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: var(--graphite);
}

.page-about .origin-more {
  margin: 1.5rem 0 0;
}

.page-about .about-media {
  position: relative;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background: var(--navy);
  border: 1px solid var(--line-gold);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

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

.page-about .media-caption {
  margin: 0.75rem 0 0;
  font-size: 0.8125rem;
  line-height: 1.65;
  color: rgba(38, 49, 59, 0.72);
}

.page-about .media-caption--on-dark {
  color: rgba(245, 242, 234, 0.66);
}

/* ---------- 02 版本时间线 ---------- */
.page-about .tl-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0 0 1.5rem;
  padding: 0;
  list-style: none;
  font-size: 0.75rem;
  letter-spacing: 0.1em;
}

.page-about .tl-jump a {
  display: inline-block;
  padding: 0.35rem 0.7rem;
  border: 1px solid var(--line-gold);
  color: var(--navy);
  text-decoration: none;
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease);
}

.page-about .tl-jump a:hover,
.page-about .tl-jump a:focus-visible {
  background: var(--navy);
  color: var(--gold);
}

.page-about .tl-list {
  display: grid;
  gap: 0;
}

.page-about .tl-item {
  position: relative;
  padding: 1.5rem 0 1.5rem 1.85rem;
  border-top: 1px solid var(--line-ink);
  scroll-margin-top: 6rem;
}

.page-about .tl-item:first-child {
  border-top: 0;
  padding-top: 0.35rem;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.9rem;
  width: 0.5rem;
  height: 0.5rem;
  background: var(--gold);
  transform: rotate(45deg);
  transition: background-color 0.18s var(--ease), box-shadow 0.18s var(--ease);
}

.page-about .tl-item:first-child::before {
  top: 0.75rem;
}

.page-about .tl-item::after {
  content: "";
  position: absolute;
  left: 0.24rem;
  top: 2.5rem;
  bottom: -0.35rem;
  width: 1px;
  background: var(--line-gold);
}

.page-about .tl-item:first-child::after {
  top: 1.35rem;
}

.page-about .tl-item:last-child::after {
  content: none;
}

.page-about .tl-item:hover::before,
.page-about .tl-item:focus-within::before {
  background: var(--amber);
  box-shadow: 0 0 0 4px rgba(230, 162, 60, 0.18);
}

.page-about .tl-rail {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 0.6rem;
}

.page-about .tl-phase {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.2em;
  color: var(--jade);
}

.page-about .tl-version {
  font-family: var(--mono);
  font-size: 1.125rem;
  letter-spacing: 0.04em;
  color: var(--ink);
  padding: 0.1rem 0.5rem;
  border: 1px solid var(--line-gold);
}

.page-about .tl-title {
  margin: 0 0 0.5rem;
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(1.125rem, 2.6vw, 1.375rem);
  line-height: 1.4;
  color: var(--ink);
}

.page-about .tl-text {
  margin: 0;
  max-width: 62ch;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--graphite);
}

.page-about .tl-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0.9rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .tl-tags li {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  padding: 0.25rem 0.55rem;
  color: var(--ink);
  background: rgba(111, 175, 158, 0.18);
  border: 1px solid rgba(111, 175, 158, 0.55);
}

.page-about .tl-more {
  margin: 0.9rem 0 0;
}

/* ---------- 03 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4vw, 2.75rem);
}

.page-about .team-text {
  margin: 1.15rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--graphite);
}

.page-about .role-card {
  background: var(--paper);
  border: 1px solid rgba(38, 49, 59, 0.14);
  border-left: 3px solid var(--jade);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
  transition: border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}

.page-about .role-card + .role-card {
  margin-top: 0.7rem;
}

.page-about .role-card:hover,
.page-about .role-card[open] {
  border-left-color: var(--gold);
  background: rgba(230, 223, 208, 0.92);
}

.page-about .role-summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto auto;
  align-items: center;
  gap: 0.65rem;
  padding: 0.95rem 1rem;
  cursor: pointer;
  list-style: none;
}

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

.page-about .role-summary::marker {
  content: "";
}

.page-about .role-summary:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: -2px;
}

.page-about .role-index {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .role-name {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 1.0625rem;
  color: var(--ink);
  letter-spacing: 0.01em;
}

.page-about .role-count {
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--navy);
  padding: 0.15rem 0.45rem;
  border: 1px solid rgba(18, 46, 74, 0.22);
}

.page-about .role-arrow {
  width: 0.5rem;
  height: 0.5rem;
  margin-right: 0.25rem;
  border-right: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
  transform: rotate(45deg);
  transition: transform 0.2s var(--ease);
}

.page-about .role-card[open] .role-arrow {
  transform: rotate(-135deg);
}

.page-about .role-body {
  padding: 0 1rem 1.1rem 2.35rem;
}

.page-about .role-body p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: var(--graphite);
}

/* ---------- 04 质量保障 ---------- */
.page-about .quality-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4vw, 3rem);
}

.page-about .step-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1.15rem;
}

.page-about .step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.2rem 1.1rem;
  padding-top: 1.1rem;
  border-top: 1px solid var(--line-ink);
}

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

.page-about .step-num {
  grid-row: span 2;
  font-size: 1.5rem;
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--gold);
}

.page-about .step-title {
  margin: 0;
  font-family: var(--serif);
  font-weight: 500;
  font-size: 1.0625rem;
  color: var(--ink);
}

.page-about .step-text {
  margin: 0.35rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: var(--graphite);
}

.page-about .cert-panel {
  padding: clamp(1.25rem, 3vw, 2rem);
  background: var(--navy);
  color: var(--mist);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .cert-kicker {
  margin: 0 0 0.9rem;
  font-size: 0.6875rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .cert-list {
  margin: 0 0 1.25rem;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.5rem;
}

.page-about .cert-list li {
  position: relative;
  padding-left: 1.1rem;
  font-size: 0.875rem;
  line-height: 1.6;
  color: rgba(245, 242, 234, 0.86);
}

.page-about .cert-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55rem;
  width: 0.4rem;
  height: 0.4rem;
  background: var(--jade);
  transform: rotate(45deg);
}

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

.page-about .cert-stat {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.35rem 1rem;
  padding: 0.8rem 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .cert-stat-value {
  font-size: 1.25rem;
  letter-spacing: 0.03em;
  color: var(--gold);
}

.page-about .cert-stat-label {
  font-size: 0.8125rem;
  line-height: 1.55;
  color: rgba(245, 242, 234, 0.7);
}

/* ---------- 05 服务覆盖 ---------- */
.page-about .coverage-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4vw, 3rem);
}

.page-about .coverage-lede {
  margin: 0;
  max-width: 56ch;
  font-size: clamp(0.9375rem, 1.5vw, 1.0625rem);
  line-height: 1.82;
  color: rgba(245, 242, 234, 0.82);
}

.page-about .coverage-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1rem;
  margin: 1.6rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .coverage-stat {
  padding-top: 0.85rem;
  border-top: 1px solid var(--line-gold);
}

.page-about .coverage-num {
  display: block;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.page-about .coverage-label {
  display: block;
  margin-top: 0.45rem;
  font-size: 0.8125rem;
  line-height: 1.6;
  color: rgba(245, 242, 234, 0.7);
}

.page-about .coverage-notes {
  margin: 1.6rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.75rem;
}

.page-about .coverage-notes li {
  position: relative;
  padding-left: 1.1rem;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: rgba(245, 242, 234, 0.8);
}

.page-about .coverage-notes li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6rem;
  width: 0.45rem;
  height: 1px;
  background: var(--celadon);
}

.page-about .coverage-more {
  margin: 1.5rem 0 0;
}

.page-about .coverage-media {
  position: relative;
  overflow: hidden;
  background: var(--navy);
  border: 1px solid var(--line-gold);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

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

/* ---------- 06 服务承诺 ---------- */
.page-about .promise-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.85rem;
}

.page-about .promise-item {
  padding: 1.1rem 1.1rem 1.25rem;
  background: var(--paper);
  border-left: 2px solid var(--gold);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
}

.page-about .promise-num {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .promise-title {
  margin: 0.4rem 0 0.35rem;
  font-family: var(--serif);
  font-weight: 500;
  font-size: 1.0625rem;
  color: var(--ink);
}

.page-about .promise-text {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--graphite);
}

.page-about .about-cta {
  margin-top: clamp(1.75rem, 4vw, 2.75rem);
  padding-top: 1.5rem;
  border-top: 1px solid var(--line-ink);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem 1.5rem;
}

.page-about .cta-text {
  flex: 1 1 260px;
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--graphite);
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

.page-about .cta-actions .btn {
  min-height: 44px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .promise-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .tl-item {
    display: grid;
    grid-template-columns: 170px minmax(0, 1fr);
    column-gap: 2.25rem;
    padding-left: 2.1rem;
  }

  .page-about .tl-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.45rem;
    margin-bottom: 0;
  }
}

@media (min-width: 920px) {
  .page-about .origin-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
    align-items: start;
  }

  .page-about .quality-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: start;
  }

  .page-about .coverage-grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: start;
  }
}

@media (min-width: 1100px) {
  .page-about .promise-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-hero-title {
    max-width: 16ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-link,
  .page-about .tl-item::before,
  .page-about .role-card,
  .page-about .role-arrow,
  .page-about .tl-jump a,
  .page-about .about-breadcrumb .breadcrumb-link {
    transition: none;
  }
}
<<<END>>>