.page-about {
  --about-rail: 88px;
  --about-ink-soft: #2A3342;
  --about-rule: rgba(11, 27, 51, .16);
  --about-rule-soft: rgba(11, 27, 51, .1);
  background: var(--paper);
  color: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(26px, 4vw, 48px) 0 clamp(42px, 6vw, 76px);
  background:
    radial-gradient(110% 80% at 12% 0%, rgba(79, 195, 217, .16), transparent 62%),
    radial-gradient(90% 70% at 92% 8%, rgba(224, 58, 58, .12), transparent 60%),
    linear-gradient(180deg, var(--ink) 0%, var(--ink-deep) 100%);
  color: var(--paper);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(244, 240, 230, .055) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(244, 240, 230, .055) 1px, transparent 1px);
  background-size: 68px 68px;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -80px;
  bottom: -120px;
  width: 320px;
  height: 320px;
  border: 3px solid rgba(244, 240, 230, .1);
  border-radius: 50%;
  pointer-events: none;
}

.page-about .about-hero > .wrap {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .breadcrumb-list,
.page-about .about-hero .breadcrumb-list a {
  color: var(--steel);
}

.page-about .about-hero .breadcrumb-list [aria-current="page"] {
  color: var(--paper);
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .about-kicker {
  margin: 0;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--cyan);
  text-transform: uppercase;
}

.page-about .about-title {
  margin: 14px 0 18px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(29px, 5.6vw, 56px);
  line-height: 1.1;
  letter-spacing: -.015em;
  color: var(--paper);
  text-shadow: 5px 5px 0 rgba(224, 58, 58, .5);
  max-width: 17em;
}

.page-about .about-lede {
  margin: 0;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: #C6D1E0;
  max-width: 38em;
}

.page-about .about-cta-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 22px;
  margin-top: 28px;
}

.page-about .about-textlink {
  color: var(--yellow);
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  border-bottom: 2px solid rgba(242, 194, 48, .5);
  padding-bottom: 2px;
  transition: border-color .2s var(--ease), color .2s var(--ease);
}

.page-about .about-textlink:hover {
  color: var(--paper);
  border-color: var(--paper);
}

.page-about .about-hero-aside {
  display: grid;
  gap: 14px;
  align-content: end;
}

.page-about .about-plate {
  border: var(--line-bold) solid var(--paper);
  background: rgba(244, 240, 230, .06);
  padding: 16px 18px;
  box-shadow: var(--shadow-hard-sm);
}

.page-about .about-plate--clay {
  border-color: var(--clay);
  background: rgba(180, 98, 60, .18);
}

.page-about .about-plate-label {
  margin: 0 0 8px;
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--steel);
  text-transform: uppercase;
}

.page-about .about-plate--clay .about-plate-label {
  color: #E3B49C;
}

.page-about .about-plate-value {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1.1;
  color: var(--paper);
}

.page-about .about-plate--clay .about-plate-value {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 17px;
  line-height: 1.6;
}

/* ---------- 章节长卷 ---------- */
.page-about .about-archive {
  padding: clamp(36px, 5vw, 64px) 0 clamp(48px, 7vw, 88px);
  background: var(--paper);
}

.page-about .chapter {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  padding: clamp(30px, 4.4vw, 56px) 0;
  border-top: var(--line-bold) solid var(--about-rule);
}

.page-about .chapter-body {
  min-width: 0;
}

.page-about .chapter-rail {
  position: relative;
}

.page-about .chapter-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border: var(--line-bold) solid var(--ink);
  background: var(--moss);
  color: var(--paper);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: .04em;
  box-shadow: var(--shadow-hard-sm);
}

.page-about .chapter-title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(23px, 3.4vw, 38px);
  line-height: 1.22;
  letter-spacing: -.01em;
  color: var(--ink);
}

.page-about .chapter-intro {
  margin: 0 0 26px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-ink-soft);
  max-width: 42em;
}

/* ---------- 01 用途 ---------- */
.page-about .use-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2px;
  background: var(--about-rule);
  border: var(--line-bold) solid var(--ink);
  box-shadow: var(--shadow-hard-sm);
}

.page-about .use-cell {
  background: #FFFDF7;
  padding: 22px 20px 24px;
}

.page-about .use-title {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
  padding-left: 12px;
  border-left: 5px solid var(--clay);
}

.page-about .use-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-ink-soft);
}

.page-about .device-strip {
  margin-top: 26px;
  border: var(--line) solid var(--ink);
  border-left: 9px solid var(--cyan);
  background: #FFFDF7;
  padding: 18px 20px 20px;
}

.page-about .device-strip-label {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--ink);
  text-transform: uppercase;
}

.page-about .device-strip-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-ink-soft);
  max-width: 46em;
}

/* ---------- 02 数据流程 ---------- */
.page-about .stage-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .stage-card {
  position: relative;
  border: var(--line-bold) solid var(--ink);
  background: #FFFDF7;
  padding: 20px 20px 22px;
  box-shadow: var(--shadow-hard-sm);
  transition: transform .22s var(--ease), box-shadow .22s var(--ease);
}

.page-about .stage-card:hover,
.page-about .stage-card:focus-within {
  transform: translateY(-4px);
  box-shadow: 8px 10px 0 rgba(4, 10, 20, .5);
}

.page-about .stage-time {
  display: inline-block;
  margin: 0 0 14px;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--steel);
  background: transparent;
  border: 2px dashed var(--steel);
  transition: background .22s var(--ease), color .22s var(--ease), border-color .22s var(--ease), border-style .22s var(--ease);
}

.page-about .stage-card:hover .stage-time,
.page-about .stage-card:focus-within .stage-time {
  background: var(--yellow);
  color: var(--ink);
  border: 2px solid var(--ink);
}

.page-about .stage-title {
  margin: 0 0 12px;
  font-size: 19px;
  font-weight: 800;
  color: var(--ink);
}

.page-about .stage-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.page-about .stage-list li {
  position: relative;
  padding-left: 16px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--about-ink-soft);
}

.page-about .stage-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 7px;
  height: 7px;
  background: var(--moss);
}

/* ---------- 图片容器 ---------- */
.page-about .about-figure {
  margin: 28px 0 0;
}

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

.page-about .about-figure--wide {
  margin-top: 0;
  margin-bottom: 30px;
}

.page-about .about-figure .media-caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--steel);
}

/* ---------- 03 时间轴 ---------- */
.page-about .timeline {
  position: relative;
  margin-top: 8px;
  padding-left: 30px;
  border-left: 3px solid var(--moss);
}

.page-about .tl-item {
  position: relative;
  margin-bottom: 14px;
  border: var(--line) solid var(--ink);
  background: #FFFDF7;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 24px;
  width: 14px;
  height: 14px;
  background: var(--clay);
  transform: translateX(-50%);
  box-shadow: 0 0 0 3px var(--paper);
}

.page-about .tl-item[open] {
  box-shadow: var(--shadow-hard-sm);
}

.page-about .tl-summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 18px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .tl-year {
  flex: 0 0 auto;
  min-width: 100px;
  font-size: 17px;
  font-weight: 700;
  color: var(--clay);
}

.page-about .tl-head {
  flex: 1 1 220px;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--ink);
}

.page-about .tl-mark {
  flex: 0 0 auto;
  font-size: 20px;
  font-weight: 700;
  color: var(--moss);
  transition: transform .22s var(--ease);
}

.page-about .tl-item[open] .tl-mark {
  transform: rotate(45deg);
}

.page-about .tl-body {
  margin: 0;
  padding: 14px 18px 18px;
  border-top: 2px dashed var(--about-rule);
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-ink-soft);
}

/* ---------- 04 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

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

.page-about .role-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  border: var(--line) solid var(--ink);
  border-left: 9px solid var(--moss);
  background: #FFFDF7;
  padding: 16px 18px 18px;
}

.page-about .role-num {
  font-size: 21px;
  font-weight: 700;
  color: var(--clay);
}

.page-about .role-body {
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-ink-soft);
}

.page-about .role-body strong {
  color: var(--ink);
  font-weight: 700;
}

/* ---------- 05 规模 ---------- */
.page-about .scale-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  background: var(--about-rule);
  border: var(--line-bold) solid var(--ink);
  box-shadow: var(--shadow-hard-sm);
}

.page-about .scale-item {
  background: var(--paper);
  padding: 24px 18px 26px;
}

.page-about .scale-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(34px, 6.4vw, 60px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--ink);
}

.page-about .scale-unit {
  font-size: .42em;
  margin-left: 4px;
  color: var(--clay);
}

.page-about .scale-label {
  display: block;
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--about-ink-soft);
}

/* ---------- 06 资质与合作 ---------- */
.page-about .cred-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.page-about .cred-card {
  border: var(--line) solid var(--ink);
  border-top: 9px solid var(--clay);
  background: #FFFDF7;
  padding: 20px 20px 22px;
}

.page-about .cred-label {
  margin: 0 0 10px;
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--steel);
  text-transform: uppercase;
}

.page-about .cred-value {
  margin: 0 0 12px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ink);
}

.page-about .cred-value.mono {
  font-family: var(--font-mono);
  font-size: 16px;
  letter-spacing: .02em;
}

.page-about .cred-text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--about-ink-soft);
}

.page-about .about-next {
  margin-top: 32px;
  border: var(--line-bold) solid var(--ink);
  background: var(--ink);
  box-shadow: var(--shadow-hard);
  padding: 24px clamp(18px, 3vw, 32px) 26px;
}

.page-about .next-title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 800;
  color: var(--paper);
}

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

.page-about .next-link {
  display: inline-flex;
  align-items: center;
  border: var(--line) solid var(--paper);
  color: var(--paper);
  font-size: 14px;
  font-weight: 600;
  padding: 9px 16px;
  text-decoration: none;
  transition: background .2s var(--ease), color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .next-link:hover,
.page-about .next-link:focus-visible {
  background: var(--signal, var(--yellow));
  border-color: var(--yellow);
  color: var(--ink);
}

/* ---------- 响应式 ---------- */
@media (min-width: 560px) {
  .page-about .role-item {
    grid-template-columns: 92px minmax(0, 1fr);
    align-items: baseline;
    gap: 18px;
  }
}

@media (min-width: 760px) {
  .page-about .use-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

@media (min-width: 860px) {
  .page-about .chapter {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 42px;
  }

  .page-about .chapter-rail {
    position: sticky;
    top: 26px;
    align-self: start;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 400px);
    align-items: start;
    gap: 40px;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 48px;
    align-items: end;
  }
}

@media (max-width: 480px) {
  .page-about .about-title {
    text-shadow: 3px 3px 0 rgba(224, 58, 58, .5);
  }

  .page-about .scale-grid {
    grid-template-columns: 1fr;
  }

  .page-about .timeline {
    padding-left: 22px;
  }

  .page-about .tl-item::before {
    left: -22px;
  }
}

@media (hover: none) {
  .page-about .stage-time {
    background: var(--yellow);
    color: var(--ink);
    border: 2px solid var(--ink);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage-card,
  .page-about .tl-mark,
  .page-about .next-link,
  .page-about .about-textlink {
    transition: none;
  }

  .page-about .stage-card:hover {
    transform: none;
  }
}