.page-about {
  --about-rail: 96px;
  --about-line: rgba(154, 168, 181, 0.18);
  color: var(--c-paper);
}

/* 顶部：面包屑与返回入口 */
.page-about .about-topbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  align-items: center;
  justify-content: space-between;
  padding-top: 18px;
  padding-bottom: 18px;
}
.page-about .about-toplink {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 224, 200, 0.35);
  padding-bottom: 2px;
  transition: color 0.2s ease-out, border-color 0.2s ease-out;
}
.page-about .about-toplink:hover {
  color: var(--c-green);
  border-color: var(--c-green);
}

/* 首屏 */
.page-about .about-hero {
  padding: 6px 0 42px;
}
.page-about .about-hero__inner {
  display: grid;
  gap: 30px;
}
.page-about .about-hero__kicker {
  margin: 0 0 14px;
  color: var(--c-gold);
}
.page-about .about-hero h1 {
  margin: 0 0 18px;
  font-size: clamp(29px, 4.4vw + 12px, 52px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  font-weight: 800;
}
.page-about .about-hero__lead {
  margin: 0;
  font-size: 17px;
  line-height: 1.85;
  color: rgba(242, 245, 247, 0.84);
  max-width: 58ch;
}
.page-about .about-facts {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 18px;
}
.page-about .about-facts li {
  border-top: 1px solid var(--line-strong);
  padding-top: 12px;
}
.page-about .about-facts__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 22px;
  letter-spacing: -0.01em;
  color: var(--c-cyan);
}
.page-about .about-facts__txt {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-shale);
}
.page-about .about-hero__cta {
  margin: 26px 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.page-about .about-hero__frame {
  aspect-ratio: 4 / 3;
  overflow: hidden;
}
.page-about .about-hero__frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* 章节跳转条 */
.page-about .about-jump {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(18, 40, 61, 0.7), rgba(11, 27, 43, 0.25));
}
.page-about .about-jump__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 16px;
  padding-top: 14px;
  padding-bottom: 14px;
}
.page-about .about-jump ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.page-about .about-jump a {
  display: block;
  font-size: 13px;
  color: var(--c-shale);
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 5px 10px;
  transition: color 0.2s ease-out, background 0.2s ease-out, border-color 0.2s ease-out;
}
.page-about .about-jump a:hover,
.page-about .about-jump a:focus-visible {
  color: var(--c-deep);
  background: var(--c-cyan);
  border-color: var(--c-cyan);
}

/* 主体骨架：左侧档案栏 + 纵向正文 */
.page-about .about-body {
  display: grid;
  gap: 22px;
  padding-top: 34px;
  padding-bottom: 60px;
}
.page-about .about-rail {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
  border-top: 1px solid var(--line);
  padding-top: 12px;
}
.page-about .about-rail__label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--c-shale);
}
.page-about .about-rail__ticks {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 10px;
}
.page-about .about-rail__ticks li {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-old-tag);
  border: 1px solid var(--line);
  padding: 2px 7px;
  border-radius: var(--radius);
}

.page-about .about-flow {
  min-width: 0;
}
.page-about .about-section {
  border-top: 1px solid var(--line);
  padding: 34px 0 8px;
}
.page-about .about-section:first-child {
  border-top: none;
  padding-top: 0;
}
.page-about .about-section .section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 16px;
  justify-content: space-between;
}
.page-about .about-section .section-head__title {
  margin: 0;
  font-size: clamp(23px, 2.4vw + 12px, 32px);
  line-height: 1.25;
  letter-spacing: -0.015em;
}
.page-about .about-section .section-head .mono-label {
  color: var(--c-old-tag);
}

/* 起点 */
.page-about .about-origin {
  display: grid;
  gap: 22px;
  margin-top: 18px;
}
.page-about .about-origin__text p {
  margin: 0 0 1em;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(242, 245, 247, 0.82);
}
.page-about .about-origin__text p:last-child {
  margin-bottom: 0;
}
.page-about .origin-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}
.page-about .origin-list li {
  border: 1px solid var(--line);
  border-left: 2px solid var(--c-cyan);
  background: var(--c-ink);
  padding: 14px 16px;
  box-shadow: var(--shadow-soft);
}
.page-about .origin-list__tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--c-cyan);
  margin-bottom: 8px;
}
.page-about .origin-list p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(242, 245, 247, 0.8);
}

/* 时间轴 */
.page-about .about-timeline-band {
  aspect-ratio: 8 / 3;
  overflow: hidden;
  margin-top: 20px;
}
.page-about .about-timeline-band img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.page-about .about-timeline {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
}
.page-about .about-node {
  position: relative;
  border-top: 1px solid var(--line-strong);
  padding-top: 16px;
}
.page-about .about-node::before {
  content: "";
  position: absolute;
  top: -4px;
  left: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--c-old-tag);
}
.page-about .about-node--new::before {
  background: var(--c-green);
  box-shadow: 0 0 0 4px rgba(25, 198, 160, 0.18);
}
.page-about .about-node__tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--c-old-tag);
  background: rgba(42, 54, 68, 0.85);
  border: 1px solid var(--line);
  padding: 2px 7px;
  border-radius: var(--radius);
}
.page-about .about-node--new .about-node__tag {
  color: var(--c-deep);
  background: var(--c-green);
  border-color: var(--c-green);
}
.page-about .about-node__title {
  margin: 12px 0 8px;
  font-size: 17px;
  line-height: 1.45;
  letter-spacing: -0.01em;
}
.page-about .about-node details {
  border-top: 1px dashed var(--line);
  padding-top: 8px;
}
.page-about .about-node summary {
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-cyan);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.page-about .about-node summary::-webkit-details-marker {
  display: none;
}
.page-about .about-node summary::after {
  content: "＋";
  transition: transform 0.22s ease-out;
}
.page-about .about-node details[open] summary::after {
  content: "－";
}
.page-about .about-node details p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(242, 245, 247, 0.78);
}

/* 团队 */
.page-about .about-team {
  display: grid;
  gap: 22px;
  margin-top: 20px;
}
.page-about .about-team__text p {
  margin: 0 0 1em;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(242, 245, 247, 0.82);
}
.page-about .about-team__text p:last-child {
  margin-bottom: 0;
}
.page-about .about-team__media {
  aspect-ratio: 5 / 4;
  overflow: hidden;
}
.page-about .about-team__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.page-about .team-grid {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}
.page-about .team-card {
  border: 1px solid var(--line);
  background: var(--c-ink);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow-soft);
  transition: border-color 0.22s ease-out, transform 0.22s ease-out;
}
.page-about .team-card:hover {
  border-color: var(--c-green);
  transform: translateY(-3px);
}
.page-about .team-card__badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-gold);
  border: 1px solid rgba(232, 180, 90, 0.42);
  padding: 2px 7px;
  border-radius: var(--radius);
}
.page-about .team-card__title {
  margin: 12px 0 8px;
  font-size: 18px;
  letter-spacing: -0.01em;
}
.page-about .team-card__duty {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(242, 245, 247, 0.78);
}

/* 规范 */
.page-about .rule-list {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}
.page-about .rule-list li {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}
.page-about .rule-list__no {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--c-gold);
  border-top: 1px solid var(--c-gold-dark);
  padding-top: 4px;
}
.page-about .rule-list__title {
  margin: 0 0 8px;
  font-size: 17px;
  letter-spacing: -0.01em;
}
.page-about .rule-list p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(242, 245, 247, 0.8);
}

/* 设备指南迭代 */
.page-about .about-guide__lead {
  margin: 18px 0 20px;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(242, 245, 247, 0.82);
  max-width: 62ch;
}
.page-about .guide-strip {
  list-style: none;
  margin: 0;
  padding: 4px 0 14px;
  display: flex;
  gap: 12px;
  overflow-x: auto;
}
.page-about .guide-step {
  flex: 0 0 182px;
  border: 1px solid var(--line);
  background: var(--c-old);
  border-radius: var(--radius);
  padding: 14px;
}
.page-about .guide-step--old {
  background: rgba(42, 54, 68, 0.72);
}
.page-about .guide-step--new {
  background: var(--c-ink);
  border-color: rgba(47, 224, 200, 0.4);
}
.page-about .guide-step__ver {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--c-old-tag);
  margin-bottom: 10px;
}
.page-about .guide-step--new .guide-step__ver {
  color: var(--c-cyan);
}
.page-about .guide-step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(242, 245, 247, 0.8);
}
.page-about .term-bar {
  display: flex;
  height: 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.page-about .term-bar span {
  flex: 1 1 0;
  border-right: 1px solid rgba(11, 27, 43, 0.85);
}
.page-about .term-bar span:last-child {
  border-right: none;
}
.page-about .term-bar .is-old {
  background: rgba(108, 126, 146, 0.55);
}
.page-about .term-bar .is-new {
  background: linear-gradient(90deg, var(--c-green), var(--c-cyan));
}
.page-about .term-bar__note {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-shale);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 10px;
}
.page-about .term-bar__arrow {
  font-family: var(--font-mono);
  color: var(--c-gold);
}

/* 协作与去向 */
.page-about .about-partner {
  display: grid;
  gap: 22px;
  margin-top: 20px;
}
.page-about .about-partner__text p {
  margin: 0 0 1em;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(242, 245, 247, 0.82);
}
.page-about .about-partner__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}
.page-about .about-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}
.page-about .about-links a {
  display: grid;
  gap: 4px;
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--c-ink);
  padding: 12px 14px;
  color: var(--c-paper);
  font-size: 15px;
  transition: border-color 0.2s ease-out, background 0.2s ease-out;
}
.page-about .about-links a:hover {
  border-color: var(--c-cyan);
  background: rgba(47, 224, 200, 0.08);
}
.page-about .about-links span {
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-shale);
}

/* 平板与桌面 */
@media (min-width: 700px) {
  .page-about .about-hero {
    padding-bottom: 52px;
  }
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-body {
    padding-top: 44px;
    padding-bottom: 76px;
  }
  .page-about .about-section {
    padding: 42px 0 12px;
  }
  .page-about .about-origin {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 28px;
  }
  .page-about .about-timeline {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px 20px;
  }
  .page-about .about-team {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 28px;
    align-items: center;
  }
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-partner {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 28px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.18fr) minmax(0, 0.82fr);
    gap: 44px;
    align-items: center;
  }
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 40px;
  }
  .page-about .about-rail {
    position: sticky;
    top: 104px;
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 22px;
    border-top: none;
    border-right: 1px solid var(--line);
    padding: 4px 16px 0 0;
  }
  .page-about .about-rail__label {
    writing-mode: vertical-rl;
    letter-spacing: 0.24em;
    padding-top: 6px;
  }
  .page-about .about-rail__ticks {
    flex-direction: column;
    gap: 8px;
  }
  .page-about .about-timeline {
    grid-template-columns: repeat(6, minmax(0, 1fr));
    gap: 18px 14px;
  }
  .page-about .about-node__title {
    font-size: 15px;
  }
  .page-about .about-node details p {
    font-size: 13px;
  }
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1200px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}