.page-about {
  --about-chapter-y: clamp(64px, 9vw, 128px);
  --about-card-line: rgba(246, 242, 233, 0.12);
  --about-body-soft: rgba(246, 242, 233, 0.8);
  background: var(--ink);
  color: var(--porcelain);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.85;
  overflow-x: clip;
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

.page-about .about-wrap {
  width: 100%;
  max-width: var(--shell-max);
  margin-inline: auto;
  padding-inline: clamp(20px, 5vw, 64px);
}

.page-about .inline-link {
  color: var(--gold-light);
  text-decoration: none;
  border-bottom: 1px solid var(--rail-line);
  transition: color 200ms var(--ease), border-color 200ms var(--ease);
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(40px, 6vw, 76px) 0 clamp(44px, 7vw, 88px);
  background:
    radial-gradient(120% 90% at 86% 0%, rgba(216, 169, 78, 0.16), transparent 62%),
    radial-gradient(90% 84% at 0% 100%, rgba(18, 63, 60, 0.55), transparent 62%),
    var(--ink);
  border-bottom: 1px solid var(--hair-line);
}

.page-about .breadcrumb {
  margin-bottom: clamp(28px, 4vw, 44px);
}

.page-about .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.page-about .breadcrumb-link {
  color: var(--mist);
  text-decoration: none;
  transition: color 200ms var(--ease);
}

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

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

.page-about .hero-eyebrow {
  margin: 0 0 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .hero-title {
  margin: 0 0 26px;
  max-width: 19ch;
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: clamp(2.1rem, 6vw, 4.1rem);
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--porcelain);
}

.page-about .hero-lede {
  margin: 0 0 34px;
  max-width: 56ch;
  font-size: clamp(1rem, 1.5vw, 1.1rem);
  color: var(--about-body-soft);
}

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

/* ---------- 章节书签条 ---------- */
.page-about .about-tabs {
  background: rgba(22, 50, 79, 0.55);
  border-bottom: 1px solid var(--hair-line);
}

.page-about .about-tabs__inner {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: none;
  padding-block: 12px;
}

.page-about .about-tabs__inner::-webkit-scrollbar {
  display: none;
}

.page-about .about-tab {
  flex: 0 0 auto;
  padding: 8px 13px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--mist);
  text-decoration: none;
  white-space: nowrap;
  transition: color 200ms var(--ease), background 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .about-tab:hover,
.page-about .about-tab:focus-visible {
  color: var(--gold-light);
  background: rgba(216, 169, 78, 0.09);
  border-color: var(--rail-line);
}

/* ---------- 章节通用 ---------- */
.page-about .about-chapter {
  position: relative;
  padding-block: var(--about-chapter-y);
}

.page-about .chapter-head {
  padding-left: clamp(0px, 5vw, 76px);
  margin-bottom: clamp(30px, 4vw, 48px);
}

.page-about .chapter-index {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--gold);
}

.page-about .chapter-title {
  margin: 0 0 20px;
  max-width: 22ch;
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: clamp(1.75rem, 4.2vw, 2.85rem);
  line-height: 1.22;
  letter-spacing: -0.01em;
}

.page-about .chapter-lede {
  margin: 0 0 14px;
  max-width: 60ch;
  color: var(--about-body-soft);
}

/* ---------- 01 起点 ---------- */
.page-about .about-chapter--start {
  background: linear-gradient(180deg, rgba(10, 26, 47, 1), rgba(16, 38, 62, 0.92));
}

.page-about .about-start {
  display: grid;
  gap: clamp(28px, 5vw, 56px);
  align-items: start;
}

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

.page-about .start-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid var(--about-card-line);
}

.page-about .start-figure figcaption,
.page-about .timeline-figure figcaption {
  margin-top: 12px;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

/* ---------- 02 沿革 ---------- */
.page-about .about-chapter--timeline {
  background: linear-gradient(180deg, rgba(22, 50, 79, 0.94), rgba(10, 26, 47, 0.98));
  border-block: 1px solid var(--hair-line);
}

.page-about .timeline-layout {
  display: grid;
  gap: clamp(28px, 5vw, 56px);
  align-items: start;
}

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

.page-about .timeline-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid var(--about-card-line);
  opacity: 0.9;
}

.page-about .stage-list {
  margin: 0;
  padding: 4px 0 4px clamp(20px, 4vw, 46px);
  list-style: none;
  border-left: 1px solid var(--rail-line);
  display: grid;
  gap: 12px;
}

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

.page-about .stage::before {
  content: "";
  position: absolute;
  top: 26px;
  left: calc(-1 * clamp(20px, 4vw, 46px) - 5px);
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(216, 169, 78, 0.15);
}

.page-about .stage-details {
  border: 1px solid var(--about-card-line);
  border-radius: var(--radius-sm);
  background: rgba(10, 26, 47, 0.5);
  transition: background 220ms var(--ease), border-color 220ms var(--ease), transform 220ms var(--ease);
}

.page-about .stage-details:hover {
  transform: translateY(-2px);
  border-color: var(--rail-line);
  background: rgba(10, 26, 47, 0.74);
}

.page-about .stage-details[open] {
  border-color: var(--rail-line);
  background: rgba(10, 26, 47, 0.78);
}

.page-about .stage-summary {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 12px;
  padding: 16px 18px;
  list-style: none;
  cursor: pointer;
}

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

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

.page-about .stage-num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .stage-name {
  font-family: var(--font-serif);
  font-size: 1.08rem;
  color: var(--porcelain);
}

.page-about .stage-period {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--mist);
}

.page-about .stage-toggle {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--gold);
}

.page-about .stage-toggle::after {
  content: "＋";
}

.page-about .stage-details[open] .stage-toggle::after {
  content: "－";
}

.page-about .stage-body {
  padding: 0 18px 20px;
  border-top: 1px solid var(--about-card-line);
  margin-top: 2px;
  padding-top: 16px;
}

.page-about .stage-body p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--about-body-soft);
}

/* ---------- 03 栏目 ---------- */
.page-about .about-chapter--columns {
  background: var(--ink);
}

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

.page-about .column-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding: 20px 22px;
  border: 1px solid var(--about-card-line);
  border-radius: var(--radius-sm);
  background: rgba(22, 50, 79, 0.26);
  transition: background 220ms var(--ease), border-color 220ms var(--ease), transform 220ms var(--ease);
}

.page-about .column-item:hover {
  transform: translateY(-3px);
  border-color: var(--rail-line);
  background: rgba(22, 50, 79, 0.48);
}

.page-about .column-num {
  padding-top: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .column-name {
  margin: 0 0 6px;
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: 1.12rem;
  color: var(--porcelain);
}

.page-about .column-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--about-body-soft);
}

/* ---------- 04 团队 ---------- */
.page-about .about-chapter--team {
  background: linear-gradient(180deg, rgba(18, 63, 60, 0.95), rgba(10, 26, 47, 0.97));
  border-block: 1px solid var(--hair-line);
}

.page-about .team-figure {
  margin: 0 0 clamp(30px, 4vw, 52px);
}

.page-about .team-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid var(--about-card-line);
}

.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .team-card {
  padding: 24px 22px 26px;
  border: 1px solid var(--about-card-line);
  border-radius: var(--radius-lg);
  background: rgba(10, 26, 47, 0.52);
  transition: transform 220ms var(--ease), border-color 220ms var(--ease), background 220ms var(--ease);
}

.page-about .team-card:hover {
  transform: translateY(-4px);
  border-color: var(--rail-line);
  background: rgba(10, 26, 47, 0.76);
}

.page-about .team-count {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 3.2vw, 2.3rem);
  line-height: 1;
  color: var(--gold);
}

.page-about .team-name {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: 1.1rem;
  color: var(--porcelain);
}

.page-about .team-note {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--about-body-soft);
}

.page-about .team-foot {
  margin: 26px 0 0;
  padding-left: clamp(0px, 5vw, 76px);
  font-size: 14.5px;
  color: var(--mist);
}

/* ---------- 05 行业 ---------- */
.page-about .about-chapter--industries {
  background: var(--ink);
}

.page-about .industry-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .industry-tag {
  padding: 8px 18px;
  border: 1px solid rgba(242, 220, 166, 0.38);
  border-radius: 999px;
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--gold-light);
  transition: background 200ms var(--ease), color 200ms var(--ease), transform 180ms var(--ease);
}

.page-about .industry-tag:hover {
  background: var(--gold);
  color: var(--ink);
  transform: translateY(-2px);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 20px;
  margin-top: clamp(32px, 4vw, 48px);
  padding-top: clamp(26px, 3vw, 36px);
  border-top: 1px solid var(--hair-line);
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.9rem, 3.4vw, 2.5rem);
  line-height: 1.05;
  color: var(--gold);
}

.page-about .stat-label {
  display: block;
  margin-top: 8px;
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .industry-note {
  margin: 30px 0 0;
  max-width: 62ch;
  font-size: 15.5px;
  color: var(--about-body-soft);
}

/* ---------- 06 认可（浅色分区） ---------- */
.page-about .about-chapter--honors {
  background: var(--paper);
  color: #1B2430;
}

.page-about .about-chapter--honors .chapter-index {
  color: #8A6A22;
}

.page-about .about-chapter--honors .chapter-title {
  color: #14202E;
}

.page-about .about-chapter--honors .chapter-lede {
  color: #3E4A5A;
}

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

.page-about .honor-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding: 20px 22px;
  border: 1px solid rgba(20, 32, 46, 0.14);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.66);
  transition: border-color 200ms var(--ease), background 200ms var(--ease);
}

.page-about .honor-item:hover {
  border-color: rgba(138, 106, 34, 0.4);
  background: rgba(255, 255, 255, 0.92);
}

.page-about .honor-num {
  padding-top: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: #8A6A22;
}

.page-about .honor-text {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: #2A3442;
}

/* ---------- 07 合作 ---------- */
.page-about .about-chapter--start-here {
  background: linear-gradient(180deg, rgba(74, 22, 34, 0.95), rgba(10, 26, 47, 0.99));
  border-top: 1px solid var(--hair-line);
}

.page-about .start-here-layout {
  display: grid;
  gap: clamp(30px, 5vw, 58px);
  align-items: start;
}

.page-about .start-here-copy .chapter-lede {
  margin-bottom: 28px;
}

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

.page-about .start-step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding: 18px 20px;
  border: 1px solid var(--about-card-line);
  border-radius: var(--radius-sm);
  background: rgba(10, 26, 47, 0.46);
  transition: border-color 200ms var(--ease), background 200ms var(--ease), transform 200ms var(--ease);
}

.page-about .start-step:hover {
  transform: translateY(-2px);
  border-color: var(--rail-line);
  background: rgba(10, 26, 47, 0.7);
}

.page-about .step-num {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .step-text {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--about-body-soft);
}

.page-about .contact-line {
  margin: clamp(32px, 4vw, 48px) 0 0;
  padding-top: 24px;
  border-top: 1px solid var(--hair-line);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.9;
  letter-spacing: 0.04em;
  color: var(--mist);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 780px) {
  .page-about .column-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-start {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.88fr);
  }

  .page-about .start-figure {
    margin-top: 30px;
  }

  .page-about .timeline-layout {
    grid-template-columns: minmax(0, 0.62fr) minmax(0, 1fr);
  }

  .page-about .start-here-layout {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.9fr);
  }
}

@media (min-width: 1024px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .team-card:nth-child(2),
  .page-about .team-card:nth-child(4) {
    margin-top: 32px;
  }
}