.page-about {
  --ab-pad: clamp(16px, 4vw, 40px);
  --ab-idx-w: 208px;
  color: var(--paper);
  font-family: var(--font-sans);
  background:
    radial-gradient(90% 60% at 85% -8%, rgba(43, 44, 49, 0.9), transparent 62%),
    radial-gradient(60% 40% at 0% 32%, rgba(28, 29, 33, 0.85), transparent 70%),
    var(--ink);
  padding-bottom: clamp(56px, 8vw, 104px);
  overflow-x: clip;
}

.page-about .about-wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--ab-pad);
}

.page-about .eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--gold);
  margin: 0 0 14px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(22px, 4vw, 44px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(20px, 4vw, 48px);
}

.page-about .about-hero__title {
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(2.15rem, 7vw, 4.4rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 0;
}

.page-about .about-hero__accent {
  display: block;
  color: var(--gold);
  font-weight: 600;
  margin-top: 0.12em;
}

.page-about .about-hero__lead {
  margin: 0;
  font-size: clamp(0.95rem, 1.7vw, 1.06rem);
  line-height: 1.9;
  color: var(--paper-dim);
  border-top: 2px solid var(--line);
  padding-top: 18px;
  max-width: 46ch;
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 2px solid var(--line);
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-fact {
  background: var(--ink-2);
  padding: 14px 12px 16px;
  min-width: 0;
}

.page-about .about-fact__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.1rem, 3.2vw, 1.85rem);
  letter-spacing: -0.01em;
  color: var(--gold-hi);
  white-space: nowrap;
}

.page-about .about-fact__label {
  display: block;
  margin-top: 7px;
  font-size: 0.74rem;
  line-height: 1.5;
  letter-spacing: 0.04em;
  color: var(--rock);
}

/* ---------- 双栏骨架 ---------- */
.page-about .about-shell {
  margin-top: clamp(40px, 6vw, 76px);
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .about-index {
  min-width: 0;
}

.page-about .about-index__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  color: var(--rock);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index__item {
  flex: 0 0 auto;
}

.page-about .about-index__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 10px;
  border-bottom: 2px solid var(--line);
  color: var(--paper-dim);
  text-decoration: none;
  font-size: 0.85rem;
  white-space: nowrap;
  transition: color var(--t), border-color var(--t), background var(--t);
}

.page-about .about-index__num {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--gold);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--gold);
  background: rgba(201, 162, 39, 0.07);
  outline: none;
}

.page-about .about-body {
  min-width: 0;
  display: grid;
  gap: clamp(42px, 6vw, 76px);
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  scroll-margin-top: 96px;
  min-width: 0;
}

.page-about .about-sec__title {
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(1.5rem, 3.6vw, 2.3rem);
  line-height: 1.28;
  letter-spacing: -0.01em;
  margin: 0 0 14px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--line);
}

.page-about .about-lede {
  position: relative;
  margin: 16px 0 20px;
  padding-left: 16px;
  font-size: 0.92rem;
  line-height: 1.75;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.page-about .about-lede::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 8px;
  height: 2px;
  background: var(--clay);
}

.page-about .about-sec p {
  margin: 0 0 14px;
  max-width: 66ch;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--paper);
}

.page-about .about-note {
  margin-top: 16px;
  font-size: 0.82rem;
  line-height: 1.75;
  color: var(--rock);
}

.page-about .about-link {
  color: var(--gold-hi);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--t);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--cinnabar);
  outline: none;
}

.page-about .mono {
  font-family: var(--font-mono);
  color: var(--gold-hi);
  font-size: 0.94em;
}

/* ---------- 图文分栏 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
  margin-top: 6px;
}

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

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 2px solid var(--line);
  background: var(--ink-2);
}

.page-about .about-figure--tall img {
  aspect-ratio: 4 / 5;
}

.page-about .about-figure--wide img {
  aspect-ratio: 3 / 2;
  margin-bottom: 6px;
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-size: 0.76rem;
  line-height: 1.65;
  letter-spacing: 0.04em;
  color: var(--rock);
}

/* ---------- 指标网格 ---------- */
.page-about .metrics {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: 10px;
}

.page-about .metric-group {
  border: 2px solid var(--line);
  background: var(--ink-2);
  min-width: 0;
}

.page-about .metric-group__head {
  margin: 0;
  padding: 10px 12px;
  border-bottom: 2px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--clay);
}

.page-about .metric {
  border-bottom: 1px solid rgba(58, 59, 63, 0.7);
}

.page-about .metric:last-child {
  border-bottom: 0;
}

.page-about .metric > summary {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 12px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .metric__num {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--paper);
}

.page-about .metric__name {
  font-size: 0.86rem;
  color: var(--rock);
  transition: color var(--t);
}

.page-about .metric[open] > summary {
  background: rgba(201, 162, 39, 0.08);
}

.page-about .metric[open] .metric__name {
  color: var(--paper);
}

.page-about .metric__note {
  margin: 0;
  padding: 0 12px 12px 36px;
  font-size: 0.8rem;
  line-height: 1.72;
  color: var(--paper-dim);
}

/* ---------- 阶梯条 ---------- */
.page-about .ladder-wrap {
  overflow-x: auto;
  padding: 4px 0 10px;
  margin-top: 6px;
}

.page-about .ladder {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  align-items: end;
  gap: 6px;
  min-width: 470px;
}

.page-about .ladder__step {
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 5px;
  min-height: 66px;
  padding: 8px 4px 10px;
  text-align: center;
  border-top: 2px solid var(--gold);
  background: linear-gradient(180deg, rgba(201, 162, 39, 0.17), rgba(201, 162, 39, 0.02));
}

.page-about .ladder__step:nth-child(2) { min-height: 82px; }
.page-about .ladder__step:nth-child(3) { min-height: 98px; }
.page-about .ladder__step:nth-child(4) { min-height: 114px; }
.page-about .ladder__step:nth-child(5) { min-height: 130px; }
.page-about .ladder__step:nth-child(6) { min-height: 146px; }

.page-about .ladder__lvl {
  font-size: 0.74rem;
  color: var(--paper);
  letter-spacing: 0.02em;
}

.page-about .ladder__pts {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--gold);
}

/* ---------- 等级表格 ---------- */
.page-about .table-wrap {
  overflow-x: auto;
  border: 2px solid var(--line);
  background: var(--ink-2);
  margin-top: 18px;
}

.page-about .tier-table {
  width: 100%;
  min-width: 560px;
  border-collapse: collapse;
  font-size: 0.88rem;
}

.page-about .tier-table caption {
  text-align: left;
  padding: 12px 14px;
  border-bottom: 2px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--rock);
}

.page-about .tier-table th {
  text-align: left;
  padding: 10px 14px;
  border-bottom: 2px solid var(--line);
  background: var(--ink-3);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.09em;
  color: var(--rock);
  white-space: nowrap;
}

.page-about .tier-table td {
  padding: 12px 14px;
  border-bottom: 1px solid rgba(58, 59, 63, 0.7);
  color: var(--paper);
  vertical-align: top;
  line-height: 1.7;
  transition: background var(--t);
}

.page-about .tier-table tbody tr:last-child td {
  border-bottom: 0;
}

.page-about .tier-table tbody tr:hover td {
  background: rgba(201, 162, 39, 0.07);
}

.page-about .tier-table tbody tr:hover td:first-child {
  box-shadow: inset 3px 0 0 var(--gold);
}

.page-about .tier-table td:first-child {
  font-family: var(--font-serif);
  font-weight: 600;
  white-space: nowrap;
}

.page-about .tier-points {
  font-family: var(--font-mono);
  color: var(--gold);
  white-space: nowrap;
}

.page-about .tier-count {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--moss);
  white-space: nowrap;
}

/* ---------- 服务卡 ---------- */
.page-about .svc-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 8px;
}

.page-about .svc {
  border: 2px solid var(--line);
  background: var(--ink-2);
  padding: 18px 16px 20px;
  box-shadow: var(--shadow-soft);
}

.page-about .svc__title {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.08rem;
  color: var(--gold-hi);
}

.page-about .svc__text {
  margin: 0;
  font-size: 0.87rem;
  line-height: 1.82;
  color: var(--paper-dim);
}

/* ---------- 响应指标 ---------- */
.page-about .resp {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 2px solid var(--line);
  margin-top: 22px;
}

.page-about .resp__item {
  background: var(--ink-3);
  padding: 16px 14px;
}

.page-about .resp__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.1rem, 3vw, 1.55rem);
  color: var(--gold-hi);
  white-space: nowrap;
}

.page-about .resp__label {
  display: block;
  margin-top: 8px;
  font-size: 0.78rem;
  line-height: 1.6;
  color: var(--rock);
}

/* ---------- 协作生态 ---------- */
.page-about .eco-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: 12px;
}

.page-about .eco {
  border-left: 2px solid var(--clay);
  padding: 4px 0 4px 12px;
  min-width: 0;
}

.page-about .eco__name {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-serif);
  font-size: 0.94rem;
  font-weight: 600;
  color: var(--paper);
}

.page-about .eco__text {
  margin: 0;
  font-size: 0.82rem;
  line-height: 1.72;
  color: var(--rock);
}

/* ---------- 时间轴 ---------- */
.page-about .tl {
  list-style: none;
  margin: 12px 0 0;
  padding: 0 0 0 24px;
  border-left: 2px solid var(--line);
  display: grid;
  gap: 26px;
}

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

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: -32px;
  top: 4px;
  width: 14px;
  height: 14px;
  border: 2px solid var(--gold);
  border-radius: 50%;
  background: var(--ink);
  transition: background var(--t), box-shadow var(--t), border-color var(--t);
}

.page-about .tl__item:hover::before,
.page-about .tl__item:focus-within::before {
  background: var(--gold);
  box-shadow: 0 0 0 5px rgba(201, 162, 39, 0.14);
}

.page-about .tl__year {
  display: block;
  margin-bottom: 5px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .tl__title {
  margin: 0 0 6px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.12rem;
  color: var(--paper);
}

.page-about .tl__note {
  margin: 0;
  max-width: 62ch;
  font-size: 0.88rem;
  line-height: 1.82;
  color: var(--paper-dim);
}

/* ---------- 品牌主张 ---------- */
.page-about .about-creed {
  margin-top: 14px;
  border: 2px solid var(--gold);
  background: linear-gradient(158deg, rgba(20, 20, 22, 0.96), rgba(11, 11, 12, 0.97));
  padding: clamp(22px, 5vw, 44px);
  box-shadow: var(--shadow-hard);
}

.page-about .about-creed__quote {
  margin: 0 0 18px;
  max-width: none;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(1.3rem, 3.7vw, 2.05rem);
  line-height: 1.55;
  color: var(--paper);
}

.page-about .about-creed__quote::first-letter {
  float: left;
  font-size: 3em;
  line-height: 0.86;
  padding: 0.06em 10px 0 0;
  color: var(--gold-hi);
}

.page-about .about-creed__text {
  margin: 0 0 22px;
  max-width: 58ch;
  font-size: 0.94rem;
  line-height: 1.86;
  color: var(--paper-dim);
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    align-items: start;
  }

  .page-about .about-split--rev {
    grid-template-columns: minmax(0, 0.88fr) minmax(0, 1.12fr);
  }

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

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

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

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    align-items: end;
  }

  .page-about .about-shell {
    grid-template-columns: var(--ab-idx-w) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: 96px;
  }

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

  .page-about .about-index__link {
    border-bottom: 0;
    border-left: 2px solid var(--line);
    white-space: normal;
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    border-left-color: var(--gold);
    border-bottom-color: transparent;
  }
}

@media (min-width: 1100px) {
  .page-about .metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (max-width: 420px) {
  .page-about .about-fact__label {
    font-size: 0.68rem;
  }

  .page-about .about-hero__title {
    letter-spacing: -0.01em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .metric__name,
  .page-about .tier-table td,
  .page-about .tl__item::before,
  .page-about .about-link {
    transition: none;
  }
}