.page-about {
  --about-line: rgba(16, 20, 24, .16);
  --about-line-strong: rgba(16, 20, 24, .34);
  --about-line-light: rgba(250, 246, 239, .24);
  --about-muted: #4a5560;
  display: block;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  overflow-x: clip;
}

.page-about [id] {
  scroll-margin-top: 96px;
}

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

.page-about .about-section--mist {
  background: var(--mist);
}

.page-about .about-section--indigo {
  background: var(--indigo);
  color: var(--paper);
}

.page-about .about-section--sand {
  background: var(--sand);
}

.page-about .about-section--teal {
  background: var(--teal);
  color: var(--paper);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding: 22px 0 0;
  font-size: .8125rem;
  letter-spacing: .05em;
  color: var(--slate);
}

.page-about .breadcrumb a {
  color: var(--teal);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  border-bottom-color: var(--orange);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 30px 0 44px;
  display: grid;
  gap: 24px;
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(2.1rem, 7.4vw, 4.25rem);
  line-height: 1.06;
  letter-spacing: -.015em;
  max-width: 20ch;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 44rem;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: #2b3138;
}

.page-about .hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .hero-stat {
  background: var(--paper);
  padding: 16px 14px 14px;
  display: grid;
  gap: 4px;
}

.page-about .hero-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 5.6vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--teal);
}

.page-about .hero-stat--accent .hero-stat__num {
  color: var(--orange);
}

.page-about .hero-stat__label {
  font-size: .8125rem;
  letter-spacing: .08em;
  color: var(--slate);
}

/* ---------- 导读 ---------- */
.page-about .about-index {
  border-top: 1px solid var(--about-line-strong);
  border-bottom: 1px solid var(--about-line);
  padding: 16px 0 18px;
  display: grid;
  gap: 12px;
}

.page-about .about-index__label {
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .2em;
  color: var(--orange);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  counter-reset: none;
}

.page-about .about-index__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 6px 0;
  color: var(--ink);
  text-decoration: none;
  font-size: .9375rem;
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}

.page-about .about-index__num {
  font-family: var(--font-mono);
  font-size: .75rem;
  color: var(--slate);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--teal);
  border-bottom-color: var(--mustard);
}

/* ---------- 章节标题 ---------- */
.page-about .section-head {
  margin-bottom: 28px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--about-line);
  display: grid;
  gap: 8px;
}

.page-about .section-head--flush {
  border-bottom-color: var(--about-line-strong);
}

.page-about .section-head__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.5rem, 4.6vw, 2.5rem);
  line-height: 1.2;
  letter-spacing: -.01em;
}

.page-about .section-head__note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .06em;
  color: var(--slate);
}

.page-about .about-section--indigo .section-head,
.page-about .about-section--teal .section-head {
  border-bottom-color: var(--about-line-light);
}

.page-about .about-section--indigo .section-head__note {
  color: var(--mustard);
}

.page-about .about-section--teal .section-head__note {
  color: var(--mustard);
}

/* ---------- 时间轴 ---------- */
.page-about .about-section--timeline {
  position: relative;
}

.page-about .timeline-wrap {
  position: relative;
  background-image:
    linear-gradient(90deg, rgba(16, 20, 24, .045) 1px, transparent 1px),
    linear-gradient(rgba(16, 20, 24, .045) 1px, transparent 1px);
  background-size: 56px 56px;
}

.page-about .tl-rail-note {
  display: none;
}

.page-about .timeline {
  display: grid;
}

.page-about .tl-item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  padding: 26px 0 26px 22px;
  border-left: 1px solid var(--about-line-strong);
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 32px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--teal);
}

.page-about .tl-item:nth-child(3)::before,
.page-about .tl-item:nth-child(4)::before {
  border-color: var(--indigo);
}

.page-about .tl-item:nth-child(5)::before,
.page-about .tl-item:nth-child(6)::before {
  border-color: var(--orange);
  background: var(--orange);
}

.page-about .tl-year {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.page-about .tl-year__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(2.6rem, 13vw, 6rem);
  line-height: .95;
  letter-spacing: -.05em;
  color: var(--teal);
}

.page-about .tl-item:nth-child(3) .tl-year__num,
.page-about .tl-item:nth-child(4) .tl-year__num {
  color: var(--indigo);
}

.page-about .tl-item:nth-child(5) .tl-year__num,
.page-about .tl-item:nth-child(6) .tl-year__num {
  color: var(--orange);
}

.page-about .tl-year__unit {
  font-size: .8125rem;
  letter-spacing: .16em;
  color: var(--slate);
}

.page-about .tl-body__title {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 1.125rem;
  line-height: 1.5;
}

.page-about .tl-body p {
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: #2b3138;
  max-width: 44rem;
}

.page-about .tl-note {
  margin: 0;
  padding-left: 12px;
  border-left: 2px solid var(--mustard);
}

.page-about .tl-note__tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .14em;
  color: var(--wine);
  text-transform: uppercase;
}

.page-about .tl-note p {
  margin: 4px 0 0;
  font-size: .875rem;
  line-height: 1.7;
  color: var(--slate);
}

.page-about .tl-fold {
  margin-top: 14px;
  padding-top: 10px;
  border-top: 1px dashed var(--about-line-strong);
}

.page-about .tl-fold summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: .875rem;
  font-weight: 700;
  color: var(--teal);
}

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

.page-about .tl-fold summary::before {
  content: "+";
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--orange);
}

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

.page-about .tl-fold summary:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

.page-about .tl-fold p {
  margin: 10px 0 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--about-muted);
  max-width: 44rem;
}

/* ---------- 三类产品 ---------- */
.page-about .lineup-intro {
  gap: 24px;
  margin-bottom: 32px;
}

.page-about .about-section--mist .prose p {
  margin: 0 0 14px;
  font-size: 1rem;
  line-height: 1.85;
  color: #2b3138;
  max-width: 42rem;
}

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

.page-about .lineup-intro__aside {
  display: grid;
  gap: 14px;
  align-content: start;
  padding: 18px;
  background: var(--paper);
  border: 1px solid var(--about-line);
}

.page-about .lineup-intro__hint {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--about-muted);
}

.page-about .lineup {
  display: grid;
  gap: 18px;
}

.page-about .lineup__card {
  position: relative;
  padding: 26px 22px 22px;
}

.page-about .paper-corners {
  background-image:
    radial-gradient(circle, var(--mustard) 1.8px, transparent 2.2px),
    radial-gradient(circle, var(--mustard) 1.8px, transparent 2.2px),
    radial-gradient(circle, var(--mustard) 1.8px, transparent 2.2px),
    radial-gradient(circle, var(--mustard) 1.8px, transparent 2.2px);
  background-size: 5px 5px;
  background-position: left 8px top 8px, right 8px top 8px, left 8px bottom 8px, right 8px bottom 8px;
  background-repeat: no-repeat;
}

.page-about .lineup__code {
  display: block;
  font-family: var(--font-mono);
  font-size: 2.6rem;
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
  margin-bottom: 12px;
}

.page-about .lineup__card .card__title {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 1.125rem;
}

.page-about .lineup__card .card__text {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: #2b3138;
}

.page-about .lineup__meta {
  margin: 14px 0 0;
  padding-top: 10px;
  border-top: 1px solid var(--about-line);
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .06em;
  color: var(--teal);
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  gap: 32px;
}

.page-about .team-main {
  display: grid;
  gap: 28px;
  align-content: start;
}

.page-about .team-main .prose p {
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: #2b3138;
  max-width: 42rem;
}

.page-about .team-bar {
  display: grid;
  gap: 14px;
}

.page-about .team-bar__track {
  display: flex;
  height: 62px;
  border: 1px solid var(--about-line-strong);
  overflow: hidden;
}

.page-about .team-bar__seg {
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: .9375rem;
  font-weight: 700;
  transition: filter .2s ease;
}

.page-about .team-bar__seg--eng {
  flex: 0 0 36.44%;
  background: var(--teal);
  color: var(--paper);
}

.page-about .team-bar__seg--rest {
  flex: 1 1 auto;
  background: var(--mist);
  color: var(--ink);
}

.page-about .team-bar__seg:hover,
.page-about .team-bar__seg:focus-visible {
  filter: brightness(1.14);
  outline: none;
}

.page-about .team-bar__legend {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .team-bar__legend-item {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: .875rem;
}

.page-about .team-bar__dot {
  width: 10px;
  height: 10px;
  flex: 0 0 auto;
}

.page-about .team-bar__dot--eng {
  background: var(--teal);
}

.page-about .team-bar__dot--rest {
  background: var(--mist);
  border: 1px solid var(--about-line-strong);
}

.page-about .team-bar__legend-label {
  color: var(--ink);
}

.page-about .team-bar__legend-value {
  font-family: var(--font-mono);
  color: var(--orange);
}

.page-about .cert {
  padding-top: 22px;
  border-top: 1px solid var(--about-line-strong);
  display: grid;
  gap: 12px;
}

.page-about .cert__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 1.0625rem;
  line-height: 1.5;
  max-width: 30ch;
}

.page-about .cert__text {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: #2b3138;
  max-width: 42rem;
}

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

/* ---------- 区域 ---------- */
.page-about .region-grid {
  gap: 32px;
}

.page-about .region-main {
  display: grid;
  gap: 22px;
  align-content: start;
}

.page-about .region-lead {
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: rgba(250, 246, 239, .86);
  max-width: 42rem;
}

.page-about .region-list {
  border-top: 1px solid var(--about-line-light);
  border-bottom: 1px solid var(--about-line-light);
}

.page-about .region-row {
  display: grid;
  grid-template-columns: 3.6rem minmax(0, 1fr) 1.8rem 1.2rem;
  align-items: center;
  gap: 10px;
  padding: 11px 6px;
}

.page-about .region-row:nth-child(odd) {
  background: rgba(216, 230, 232, .12);
}

.page-about .region-row__name {
  font-size: .9375rem;
  letter-spacing: .08em;
}

.page-about .region-bar {
  display: block;
  height: 10px;
  background: rgba(250, 246, 239, .16);
}

.page-about .region-bar i {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--mustard), var(--orange));
}

.page-about .rb-12 { width: 100%; }
.page-about .rb-9 { width: 75%; }
.page-about .rb-6 { width: 50%; }
.page-about .rb-4 { width: 33.3%; }
.page-about .rb-2 { width: 16.7%; }
.page-about .rb-1 { width: 8.3%; }

.page-about .region-row__num {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  text-align: right;
  color: var(--mustard);
}

.page-about .region-row__unit {
  font-size: .75rem;
  color: rgba(250, 246, 239, .7);
}

.page-about .region-totals {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
  gap: 16px;
  padding: 18px 0;
  border-top: 1px solid var(--about-line-light);
  border-bottom: 1px solid var(--about-line-light);
}

.page-about .region-totals .stat {
  display: grid;
  gap: 4px;
}

.page-about .region-totals .stat__num {
  font-family: var(--font-mono);
  font-size: clamp(1.7rem, 5vw, 2.3rem);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

.page-about .region-totals .stat__label {
  font-size: .8125rem;
  letter-spacing: .08em;
  color: rgba(250, 246, 239, .72);
}

.page-about .region-note {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.85;
  color: rgba(250, 246, 239, .82);
  max-width: 42rem;
}

/* ---------- 服务标准 ---------- */
.page-about .std-grid {
  display: grid;
  gap: 22px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.page-about .std {
  padding-top: 14px;
  border-top: 3px solid var(--mustard);
  display: grid;
  gap: 6px;
  align-content: start;
}

.page-about .std__num {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 4.4vw, 2.2rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -.02em;
  color: var(--teal);
}

.page-about .std__unit {
  font-size: .5em;
  margin-left: 2px;
  color: var(--orange);
}

.page-about .std__label {
  font-size: .875rem;
  letter-spacing: .06em;
  color: var(--wine);
}

.page-about .std__text {
  margin: 4px 0 0;
  font-size: .875rem;
  line-height: 1.75;
  color: var(--about-muted);
}

.page-about .std-prose {
  margin-top: 30px;
  padding-left: 16px;
  border-left: 2px solid var(--teal);
}

.page-about .std-prose p {
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: #2b3138;
  max-width: 46rem;
}

/* ---------- 季度刷新 ---------- */
.page-about .disclosure-grid {
  gap: 32px;
}

.page-about .disclosure-main {
  display: grid;
  gap: 18px;
  align-content: start;
}

.page-about .disclosure-main .prose p {
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: #33291a;
  max-width: 40rem;
}

.page-about .disclosure-main .btn {
  justify-self: start;
}

.page-about .disclosure-parts {
  background: var(--paper);
  border: 1px solid var(--about-line-strong);
  padding: 22px 20px;
}

.page-about .disclosure-parts__title {
  margin: 0 0 14px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 1rem;
  letter-spacing: .02em;
}

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

.page-about .disclosure-part {
  display: grid;
  grid-template-columns: 2.2rem minmax(0, 1fr);
  gap: 4px 10px;
  padding: 14px 0;
  border-top: 1px solid var(--about-line);
}

.page-about .disclosure-part:first-child {
  border-top: none;
  padding-top: 0;
}

.page-about .disclosure-part__num {
  grid-row: span 2;
  font-family: var(--font-mono);
  font-size: .8125rem;
  color: var(--orange);
}

.page-about .disclosure-part__name {
  font-size: .9375rem;
  font-weight: 700;
  color: var(--teal);
}

.page-about .disclosure-part__desc {
  font-size: .875rem;
  line-height: 1.7;
  color: var(--about-muted);
}

/* ---------- 行动区 ---------- */
.page-about .about-cta {
  padding: 52px 0;
}

.page-about .about-cta__inner {
  display: grid;
  gap: 24px;
}

.page-about .about-cta__title {
  margin: 0 0 12px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.5rem, 4.6vw, 2.25rem);
  line-height: 1.2;
}

.page-about .about-cta__lead {
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: rgba(250, 246, 239, .86);
  max-width: 42rem;
}

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

.page-about .about-cta__ghost {
  color: var(--paper);
  border-color: rgba(250, 246, 239, .55);
  background: transparent;
}

.page-about .about-cta__ghost:hover,
.page-about .about-cta__ghost:focus-visible {
  border-color: var(--mustard);
  color: var(--mustard);
}

/* ---------- 收尾图 ---------- */
.page-about .about-early {
  margin: 40px auto;
}

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

.page-about .media__frame {
  background: var(--sand);
  padding: 10px;
  border: 1px solid var(--about-line);
}

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

.page-about .media__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .05em;
  color: var(--slate);
}

.page-about .about-section--indigo .media__caption {
  color: rgba(250, 246, 239, .7);
}

.page-about .about-section--indigo .media__frame {
  border-color: var(--about-line-light);
}

.page-about .team-media {
  align-self: start;
}

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .page-about .about-section {
    padding: 72px 0;
  }

  .page-about .about-hero {
    padding: 40px 0 52px;
    gap: 28px;
  }

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

  .page-about .about-index {
    grid-template-columns: auto minmax(0, 1fr);
    align-items: start;
    gap: 20px;
  }

  .page-about .section-head {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
    gap: 16px;
  }

  .page-about .section-head__note {
    text-align: right;
    padding-bottom: 4px;
  }

  .page-about .lineup {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .tl-item {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 8px 28px;
    padding: 30px 0 30px 32px;
  }

  .page-about .tl-note {
    grid-column: 2;
    max-width: 30rem;
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
    gap: 32px;
  }

  .page-about .about-early {
    max-width: 42rem;
  }
}

@media (min-width: 1000px) {
  .page-about .about-section {
    padding: 88px 0;
  }

  .page-about .timeline-wrap {
    display: grid;
    grid-template-columns: 56px minmax(0, 1fr);
    gap: 0;
  }

  .page-about .tl-rail-note {
    display: block;
    writing-mode: vertical-rl;
    text-orientation: upright;
    align-self: start;
    margin-top: 40px;
    font-family: var(--font-mono);
    font-size: 13px;
    letter-spacing: .16em;
    color: var(--slate);
    padding-left: 4px;
    border-left: 2px solid var(--mustard);
  }

  .page-about .tl-item {
    grid-template-columns: 210px minmax(0, 1fr) 200px;
    gap: 0 32px;
    padding: 36px 0 36px 40px;
  }

  .page-about .tl-item:nth-child(even) {
    padding-left: 76px;
  }

  .page-about .tl-item:nth-child(even) .tl-body {
    max-width: 34rem;
  }

  .page-about .tl-year {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .page-about .tl-note {
    grid-column: 3;
    max-width: none;
    align-self: start;
    margin-top: 6px;
  }

  .page-about .tl-body__title {
    font-size: 1.25rem;
  }

  .page-about .team-main {
    gap: 34px;
  }

  .page-about .region-totals {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-early {
    margin-top: 64px;
    margin-bottom: 72px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-fold summary::before,
  .page-about .about-index__link,
  .page-about .breadcrumb a,
  .page-about .team-bar__seg {
    transition: none;
  }
}