.page-about {
  background: var(--ink-deep);
  color: var(--warm-white);
  font-family: var(--font-body);
  max-width: var(--content-max);
  margin-inline: auto;
  padding: 24px 16px 72px;
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  margin: 0 0 22px;
}
.page-about .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .02em;
  color: var(--text-dim);
}
.page-about .breadcrumb-list li + li::before {
  content: "/";
  margin-right: 6px;
  color: var(--line-soft);
}
.page-about .breadcrumb-link {
  color: var(--blue-link);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease-out), border-color .2s var(--ease-out);
}
.page-about .breadcrumb-link:hover,
.page-about .breadcrumb-link:focus-visible {
  color: var(--gold-high);
  border-bottom-color: var(--gold-high);
}

/* ---------- 首屏封面 ---------- */
.page-about .about-cover {
  position: relative;
  padding: 4px 0 30px;
  border-bottom: 1px solid var(--line-soft);
}
.page-about .about-cover::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 96px;
  height: 2px;
  background: var(--gold);
}
.page-about .about-cover .section-kicker {
  margin: 0 0 12px;
}
.page-about .about-title {
  margin: 0 0 18px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(27px, 7.2vw, 54px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--warm-white);
  text-wrap: balance;
}
.page-about .about-lede {
  max-width: 64ch;
  margin: 0 0 28px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--text-soft);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line-faint);
  border: 1px solid var(--line-faint);
}
.page-about .about-facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 14px 16px;
  background: var(--ink-panel);
}
.page-about .fact-num {
  font-size: 21px;
  line-height: 1.2;
  color: var(--gold);
  letter-spacing: -0.01em;
}
.page-about .fact-label {
  font-size: 12px;
  line-height: 1.6;
  color: var(--text-dim);
}

/* ---------- 章节索引 ---------- */
.page-about .chapter-index {
  margin-top: 22px;
}
.page-about .chapter-caption {
  display: block;
  margin-bottom: 10px;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--text-dim);
}
.page-about .chapter-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .chapter-list a {
  display: inline-block;
  padding: 6px 12px;
  font-size: 13px;
  color: var(--text-soft);
  text-decoration: none;
  background: var(--ink-panel);
  border: 1px solid var(--line-faint);
  transition: color .2s var(--ease-out), border-color .2s var(--ease-out), background-color .2s var(--ease-out);
}
.page-about .chapter-list a:hover,
.page-about .chapter-list a:focus-visible {
  color: var(--ink-black);
  background: var(--gold-high);
  border-color: var(--gold-high);
}

/* ---------- 章节通用 ---------- */
.page-about .ab-section {
  padding-top: 56px;
}
.page-about .section-head {
  margin-bottom: 26px;
}
.page-about .section-head .section-kicker {
  margin: 0 0 10px;
}
.page-about .ab-section h2 {
  margin: 0 0 14px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(22px, 4.6vw, 32px);
  line-height: 1.25;
  letter-spacing: -0.015em;
  color: var(--warm-white);
}
.page-about .ab-section h3 {
  font-family: var(--font-head);
  font-weight: 800;
  letter-spacing: -0.01em;
}
.page-about .lede {
  max-width: 66ch;
  margin: 0;
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--text-soft);
}
.page-about .prose {
  margin: 0 0 1.1em;
  font-size: 16px;
  line-height: 1.9;
  color: var(--text-soft);
}
.page-about .prose:last-child {
  margin-bottom: 0;
}
.page-about a:not(.btn):not(.breadcrumb-link):not(.chapter-list a) {
  color: var(--blue-link);
  text-decoration: none;
  border-bottom: 1px solid var(--line-soft);
  transition: color .2s var(--ease-out), border-color .2s var(--ease-out);
}
.page-about a:not(.btn):not(.breadcrumb-link):not(.chapter-list a):hover,
.page-about a:not(.btn):not(.breadcrumb-link):not(.chapter-list a):focus-visible {
  color: var(--gold-high);
  border-bottom-color: var(--gold-high);
}

/* ---------- 图像容器 ---------- */
.page-about .figure {
  margin: 0;
}
.page-about .figure-media {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line-faint);
  background: var(--ink-panel);
}
.page-about .figure-media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .figure-caption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--text-dim);
}

/* ---------- 品牌主张 ---------- */
.page-about .lede-grid {
  display: grid;
  gap: 28px;
}
.page-about .claim-text .btn-row {
  margin-top: 24px;
}
.page-about .btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 版本演进 ---------- */
.page-about .tl-band {
  margin: 0 0 30px;
  height: 92px;
  overflow: hidden;
  border-top: 1px solid var(--line-faint);
  border-bottom: 1px solid var(--line-faint);
}
.page-about .tl-band img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .45;
}

.page-about .timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 26px;
  list-style: none;
  counter-reset: tl;
}
.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--line-soft), rgba(46,74,99,.12));
}
.page-about .tl-item {
  position: relative;
  padding: 0 0 28px;
}
.page-about .tl-item:last-child {
  padding-bottom: 0;
}
.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 7px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--ink-deep);
  border: 2px solid var(--gold);
  transition: background-color .3s var(--ease-out), box-shadow .3s var(--ease-out);
}
.page-about .tl-item:last-child::before {
  background: var(--gold);
  box-shadow: 0 0 0 5px rgba(242, 180, 65, .16);
}
.page-about .tl-meta {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--gold);
}
.page-about .tl-title {
  margin: 0 0 6px;
  font-size: 18px;
  line-height: 1.4;
  color: var(--warm-white);
}
.page-about .tl-body {
  max-width: 62ch;
  margin: 0;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text-soft);
}

/* ---------- 服务范围 ---------- */
.page-about .cap-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 0 0 26px;
  padding: 0;
  list-style: none;
  background: var(--line-faint);
  border: 1px solid var(--line-faint);
}
.page-about .cap-cell {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 18px 16px 20px;
  background: var(--ink-deep);
}
.page-about .cap-num {
  font-size: 18px;
  color: var(--gold);
}
.page-about .cap-name {
  font-size: 14px;
  font-weight: 700;
  color: var(--warm-white);
}
.page-about .cap-desc {
  font-size: 13px;
  line-height: 1.75;
  color: var(--text-dim);
}
.page-about .scope-note {
  padding: 20px 18px 22px;
}

/* ---------- 团队与协作 ---------- */
.page-about .crew {
  display: grid;
  gap: 26px;
}
.page-about .crew-list {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-faint);
}
.page-about .crew-item {
  display: grid;
  grid-template-columns: 34px 1fr;
  grid-template-areas:
    "idx name"
    "idx desc";
  column-gap: 12px;
  row-gap: 4px;
  padding: 16px 0 18px;
  border-bottom: 1px solid var(--line-faint);
}
.page-about .crew-index {
  grid-area: idx;
  font-size: 13px;
  color: var(--gold);
  line-height: 1.6;
}
.page-about .crew-name {
  grid-area: name;
  margin: 0;
  font-size: 17px;
  line-height: 1.4;
  color: var(--warm-white);
}
.page-about .crew-desc {
  grid-area: desc;
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--text-soft);
}

.page-about .partner-band {
  display: grid;
  gap: 8px;
  margin-top: 26px;
  padding: 20px 18px;
  background: var(--ink-panel);
  border-left: 3px solid var(--gold);
}
.page-about .partner-num {
  margin: 0;
  font-size: 24px;
  color: var(--gold-high);
}
.page-about .partner-text {
  margin: 0;
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text-soft);
}

/* ---------- 复核机制 ---------- */
.page-about .trust-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}
.page-about .trust-cell {
  padding: 20px 18px;
  background: var(--ink-panel);
  border-top: 2px solid var(--rail-line);
}
.page-about .trust-cell:nth-child(2) {
  border-top-color: var(--gold);
}
.page-about .trust-label {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--gold);
}
.page-about .trust-body {
  margin: 0;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text-soft);
}

/* ---------- 品牌手册 ---------- */
.page-about .tabs {
  border-top: 1px solid var(--line-faint);
}
.page-about .tab-list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  padding: 16px 0 0;
}
.page-about .tab {
  appearance: none;
  padding: 9px 16px;
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 700;
  color: var(--text-dim);
  background: transparent;
  border: 1px solid var(--line-faint);
  border-bottom: none;
  cursor: pointer;
  transition: color .2s var(--ease-out), background-color .2s var(--ease-out), border-color .2s var(--ease-out);
}
.page-about .tab:hover {
  color: var(--warm-white);
}
.page-about .tab[aria-selected="true"] {
  color: var(--ink-black);
  background: var(--gold);
  border-color: var(--gold);
}
.page-about .tab:focus-visible {
  outline: 2px solid var(--gold-high);
  outline-offset: 2px;
}
.page-about .tab-panel {
  padding: 22px 0 6px;
  border-top: 1px solid var(--gold);
}
.page-about .hb-list {
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .hb-list li {
  position: relative;
  padding: 0 0 16px 20px;
  font-size: 15px;
  line-height: 1.9;
  color: var(--text-soft);
}
.page-about .hb-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 8px;
  height: 2px;
  background: var(--gold);
}
.page-about .hb-list strong {
  color: var(--warm-white);
}

.page-about .hb-faq {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--line-faint);
}
.page-about .hb-faq-title {
  margin: 0 0 14px;
  font-size: 18px;
  color: var(--warm-white);
}
.page-about .faq-item {
  border-bottom: 1px solid var(--line-faint);
}
.page-about .faq-item summary {
  position: relative;
  padding: 15px 30px 15px 0;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.7;
  color: var(--warm-white);
  cursor: pointer;
  list-style: none;
}
.page-about .faq-item summary::-webkit-details-marker {
  display: none;
}
.page-about .faq-item summary::after {
  content: "+";
  position: absolute;
  right: 4px;
  top: 13px;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--gold);
  transition: transform .25s var(--ease-out);
}
.page-about .faq-item[open] summary::after {
  content: "−";
}
.page-about .faq-item summary:focus-visible {
  outline: 2px solid var(--gold-high);
  outline-offset: 2px;
}
.page-about .faq-item p {
  margin: 0 0 16px;
  max-width: 64ch;
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--text-soft);
}

/* ---------- 继续了解 ---------- */
.page-about .ab-next {
  padding-bottom: 8px;
}
.page-about .orbit-links {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line-faint);
  border: 1px solid var(--line-faint);
}
.page-about .orbit-link {
  display: grid;
  grid-template-columns: 40px 1fr;
  grid-template-areas:
    "idx label"
    "idx desc";
  align-items: center;
  column-gap: 14px;
  row-gap: 2px;
  padding: 16px 16px 18px;
  background: var(--ink-deep);
  text-decoration: none;
  border-bottom: none !important;
  transition: background-color .22s var(--ease-out), transform .22s var(--ease-out);
}
.page-about .orbit-link:hover,
.page-about .orbit-link:focus-visible {
  background: var(--ink-panel);
}
.page-about .orbit-index {
  grid-area: idx;
  font-size: 13px;
  color: var(--rail-line);
  transition: color .22s var(--ease-out);
}
.page-about .orbit-link:hover .orbit-index,
.page-about .orbit-link:focus-visible .orbit-index {
  color: var(--gold);
}
.page-about .orbit-label {
  grid-area: label;
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 800;
  color: var(--warm-white);
  letter-spacing: -0.01em;
}
.page-about .orbit-desc {
  grid-area: desc;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text-dim);
}

/* ---------- 平板 ---------- */
@media (min-width: 640px) {
  .page-about {
    padding: 28px 24px 84px;
  }
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .cap-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .trust-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .tl-band {
    height: 118px;
  }
  .page-about .partner-band {
    grid-template-columns: auto 1fr;
    align-items: baseline;
    gap: 20px;
  }
  .page-about .orbit-links {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .orbit-link {
    grid-template-columns: 1fr;
    grid-template-areas:
      "idx"
      "label"
      "desc";
    align-content: start;
    border-right: 1px solid var(--line-faint);
  }
  .page-about .orbit-link:last-child {
    border-right: none;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 960px) {
  .page-about .lede-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 48px;
    align-items: start;
  }
  .page-about .claim-figure {
    margin-top: 34px;
  }
  .page-about .cap-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .crew {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 44px;
    align-items: start;
  }
  .page-about .crew-figure {
    position: sticky;
    top: 24px;
  }
  .page-about .scope-note {
    padding: 26px 28px 28px;
  }
  .page-about .ab-section {
    padding-top: 72px;
  }
  .page-about .timeline {
    padding-left: 34px;
  }
  .page-about .tl-item::before {
    left: -34px;
    width: 15px;
    height: 15px;
  }
  .page-about .timeline::before {
    left: 7px;
  }
  .page-about .tl-item {
    padding-bottom: 34px;
  }
  .page-about .tl-title {
    font-size: 19px;
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about * {
    animation-duration: .001ms !important;
    transition-duration: .001ms !important;
  }
}