.page-about {
  --about-radius: 3px;
  position: relative;
  isolation: isolate;
  background:
    radial-gradient(1100px 560px at 84% -8%, rgba(0, 229, 255, 0.10), transparent 62%),
    radial-gradient(880px 520px at 6% 10%, rgba(255, 107, 53, 0.08), transparent 64%),
    var(--deep);
  color: var(--ink);
  font-family: var(--font-sans);
  padding-bottom: 72px;
  overflow-x: hidden;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(36, 64, 107, 0.24) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(36, 64, 107, 0.24) 1px, transparent 1px);
  background-size: 76px 76px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.70) 0%, rgba(0, 0, 0, 0.16) 44%, transparent 74%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.70) 0%, rgba(0, 0, 0, 0.16) 44%, transparent 74%);
}

.page-about > .container,
.page-about > section {
  position: relative;
  z-index: 1;
}

.page-about .container {
  width: 100%;
  max-width: var(--wrap);
  padding-inline: 20px;
  margin-inline: auto;
}

/* 面包屑 */
.page-about .breadcrumb {
  padding: 22px 0 2px;
}

.page-about .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--ink-dim);
}

.page-about .breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  margin-right: 10px;
  color: var(--line);
}

.page-about .breadcrumb-link {
  color: var(--cyan-soft);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color var(--ease), border-color var(--ease);
}

.page-about .breadcrumb-link:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .breadcrumb-item [aria-current="page"] {
  color: var(--white);
}

/* 通用章节头 */
.page-about .about-why,
.page-about .about-journey,
.page-about .about-team,
.page-about .about-cred,
.page-about .about-network,
.page-about .about-longterm,
.page-about .about-cross {
  padding: 50px 0;
}

.page-about .section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px 18px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 14px;
  margin-bottom: 30px;
}

.page-about .section-num {
  font-size: 13px;
  letter-spacing: 0.22em;
  color: var(--orange);
}

.page-about .section-head h2 {
  margin: 0;
  font-size: clamp(22px, 4.4vw, 38px);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .lead {
  max-width: 68ch;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ink);
}

/* 首屏 */
.page-about .about-hero {
  padding: 26px 0 48px;
}

.page-about .about-hero-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 34px;
  align-items: start;
}

.page-about .eyebrow {
  display: inline-block;
  margin: 0;
  padding: 5px 12px;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background: rgba(255, 107, 53, 0.10);
  color: var(--orange-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
}

.page-about .about-hero h1 {
  margin: 18px 0 0;
  font-size: clamp(30px, 7.2vw, 58px);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -0.025em;
  color: var(--white);
}

.page-about .about-hero .lead {
  margin: 22px 0 0;
  font-size: 16.5px;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero-facts {
  list-style: none;
  margin: 34px 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 20px;
}

.page-about .about-hero-facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.page-about .fact-num {
  font-size: clamp(22px, 4vw, 30px);
  font-weight: 700;
  color: var(--cyan);
  line-height: 1.1;
}

.page-about .about-hero-facts li:first-child .fact-num {
  color: var(--orange);
}

.page-about .fact-label {
  font-size: 13px;
  color: var(--ink-dim);
  letter-spacing: 0.04em;
}

.page-about .about-hero-mark {
  position: relative;
  margin: 0;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background: linear-gradient(158deg, rgba(18, 41, 74, 0.92), rgba(6, 19, 42, 0.92));
  box-shadow: inset 0 0 0 1px rgba(0, 229, 255, 0.05);
}

.page-about .about-hero-mark img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border-radius: 2px;
}

.page-about .about-hero-mark::after {
  content: "48°N · 117°E · TIANJIN";
  position: absolute;
  top: 22px;
  right: 8px;
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.24em;
  color: var(--cyan);
  opacity: 0.72;
  pointer-events: none;
}

.page-about .about-hero-mark .media-caption {
  display: block;
  margin-top: 12px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--ink-dim);
}

/* 01 方法论 */
.page-about .about-why-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

.page-about .about-why-body p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ink);
}

.page-about .about-why-body p:last-child {
  margin-bottom: 0;
}

.page-about .about-why-side {
  display: grid;
  gap: 14px;
}

.page-about .about-why-card {
  padding: 18px 18px 20px;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background: var(--panel);
  transition: border-color var(--ease), transform var(--ease);
}

.page-about .about-why-card:hover,
.page-about .about-why-card:focus-within {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .why-card-key {
  display: block;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--cyan-soft);
}

.page-about .about-why-card h3 {
  margin: 10px 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-why-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-dim);
}

/* 02 时间轴 */
.page-about .about-journey-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 34px;
}

.page-about .about-journey-figure {
  margin: 0 auto;
  max-width: 340px;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background: var(--abyss);
  padding: 12px;
}

.page-about .about-journey-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: 2px;
}

.page-about .about-journey-figure .media-caption {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--ink-dim);
  text-align: center;
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 30px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--orange) 0%, var(--cyan) 58%, rgba(0, 229, 255, 0.18) 100%);
}

.page-about .tl-item {
  position: relative;
  padding-bottom: 34px;
}

.page-about .tl-item:last-child {
  padding-bottom: 0;
}

.page-about .tl-dot {
  position: absolute;
  left: -30px;
  top: 4px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--deep);
  transition: border-color var(--ease), box-shadow var(--ease);
}

.page-about .tl-dot::after {
  content: "";
  position: absolute;
  inset: 4px;
  border-radius: 50%;
  background: var(--cyan);
  animation: about-node-pulse 2.4s ease-in-out infinite;
}

.page-about .tl-item.is-done .tl-dot::after {
  background: var(--orange);
}

.page-about .tl-item:hover .tl-dot,
.page-about .tl-item:focus-within .tl-dot {
  border-color: var(--cyan);
  box-shadow: 0 0 0 4px rgba(0, 229, 255, 0.14);
}

.page-about .tl-year {
  display: block;
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--orange-soft);
}

.page-about .tl-item h3 {
  margin: 8px 0 10px;
  font-size: clamp(18px, 3.4vw, 23px);
  font-weight: 800;
  color: var(--white);
  line-height: 1.3;
}

.page-about .tl-item p {
  margin: 0 0 10px;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--ink);
}

.page-about .tl-note {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ink-dim);
  padding-left: 12px;
  border-left: 2px solid rgba(0, 229, 255, 0.4);
}

@keyframes about-node-pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.7); }
}

/* 03 团队 */
.page-about .about-team-lead {
  margin: 0 0 30px;
}

.page-about .about-regions {
  list-style: none;
  margin: 0 0 34px;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  overflow: hidden;
}

.page-about .about-region {
  background: var(--panel);
  padding: 20px 18px;
  transition: background-color var(--ease), box-shadow var(--ease);
}

.page-about .about-region:hover,
.page-about .about-region:focus-visible {
  background: #16304f;
  box-shadow: inset 0 0 0 1px var(--cyan);
  outline: none;
}

.page-about .about-region h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--cyan-soft);
}

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

.page-about .about-flow-figure {
  margin: 0 0 28px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background: var(--abyss);
}

.page-about .about-flow-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: 2px;
}

.page-about .about-flow-figure .media-caption {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--ink-dim);
}

.page-about .about-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  overflow: hidden;
}

.page-about .flow-step {
  background: var(--panel);
  padding: 22px 18px;
  transition: background-color var(--ease);
}

.page-about .flow-step:hover {
  background: #16304f;
}

.page-about .flow-num {
  display: block;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--orange);
}

.page-about .flow-step h3 {
  margin: 10px 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--white);
}

.page-about .flow-step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-dim);
}

/* 04 资质 */
.page-about .about-cred-list {
  border-top: 1px solid var(--line);
}

.page-about .about-cred-item {
  border-bottom: 1px solid var(--line);
  padding: 18px 0;
}

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

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

.page-about .about-cred-item summary::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--cyan);
  transition: color var(--ease);
}

.page-about .about-cred-item[open] summary::after {
  content: "－";
}

.page-about .about-cred-item summary:hover::after,
.page-about .about-cred-item summary:focus-visible::after {
  color: var(--orange);
}

.page-about .about-cred-item summary:focus-visible {
  box-shadow: 0 0 0 2px rgba(0, 229, 255, 0.55);
  border-radius: 2px;
}

.page-about .cred-name {
  font-size: 16.5px;
  font-weight: 700;
  color: var(--white);
}

.page-about .cred-value {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cyan-soft);
}

.page-about .about-cred-item p {
  margin: 14px 0 0;
  max-width: 76ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-dim);
}

.page-about .about-cred-item p a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: border-color var(--ease);
}

.page-about .about-cred-item p a:hover {
  border-bottom-color: var(--cyan);
}

/* 05 协作网络 */
.page-about .about-network-lead {
  margin: 0 0 30px;
}

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

.page-about .network-panel {
  position: relative;
  padding: 26px 20px 22px;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background: linear-gradient(158deg, rgba(18, 41, 74, 0.95), rgba(6, 19, 42, 0.95));
  transition: border-color var(--ease), transform var(--ease);
}

.page-about .network-panel:hover,
.page-about .network-panel:focus-visible {
  border-color: var(--cyan);
  transform: translateY(-3px);
  outline: none;
}

.page-about .network-panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 20px;
  width: 42px;
  height: 2px;
  background: var(--orange);
}

.page-about .network-num {
  display: block;
  font-size: clamp(34px, 7vw, 46px);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .network-panel h3 {
  margin: 14px 0 10px;
  font-size: 18px;
  font-weight: 800;
  color: var(--white);
}

.page-about .network-panel p {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .network-note {
  margin: 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--ink-dim);
}

/* 06 长期关系 */
.page-about .about-longterm-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .longterm-card {
  display: flex;
  flex-direction: column;
  padding: 24px 20px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--orange);
  border-radius: var(--about-radius);
  background: var(--panel);
  transition: border-color var(--ease), background-color var(--ease);
}

.page-about .longterm-card:hover {
  border-color: var(--cyan);
  border-left-color: var(--cyan);
  background: #16304f;
}

.page-about .longterm-key {
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--orange-soft);
}

.page-about .longterm-card h3 {
  margin: 12px 0 10px;
  font-size: 18px;
  font-weight: 800;
  color: var(--white);
}

.page-about .longterm-card p {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.82;
  color: var(--ink);
}

.page-about .longterm-link {
  margin-top: auto;
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  padding-bottom: 2px;
  transition: color var(--ease), border-color var(--ease);
}

.page-about .longterm-link:hover {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

/* 07 交叉索引 */
.page-about .about-cross {
  padding-bottom: 24px;
}

.page-about .about-cross-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  overflow: hidden;
}

.page-about .cross-card {
  display: block;
  padding: 22px 18px;
  background: var(--abyss);
  text-decoration: none;
  transition: background-color var(--ease), box-shadow var(--ease);
}

.page-about .cross-card:hover,
.page-about .cross-card:focus-visible {
  background: #102446;
  box-shadow: inset 0 0 0 1px var(--cyan);
  outline: none;
}

.page-about .cross-key {
  display: block;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--cyan-soft);
}

.page-about .cross-card h3 {
  margin: 10px 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--white);
  transition: color var(--ease);
}

.page-about .cross-card:hover h3 {
  color: var(--cyan);
}

.page-about .cross-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--ink-dim);
}

/* 响应式 */
@media (min-width: 640px) {
  .page-about .about-hero-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

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

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

@media (min-width: 900px) {
  .page-about .about-why,
  .page-about .about-journey,
  .page-about .about-team,
  .page-about .about-cred,
  .page-about .about-network,
  .page-about .about-longterm,
  .page-about .about-cross {
    padding: 68px 0;
  }

  .page-about .about-hero {
    padding: 34px 0 66px;
  }

  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 1.22fr) minmax(0, 0.78fr);
    gap: 54px;
  }

  .page-about .about-why-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 320px);
    gap: 48px;
  }

  .page-about .about-journey-grid {
    grid-template-columns: minmax(0, 300px) minmax(0, 1fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-journey-figure {
    max-width: none;
    margin: 0;
  }

  .page-about .about-timeline {
    padding-left: 34px;
  }

  .page-about .tl-dot {
    left: -34px;
  }

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

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

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

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

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

@media (min-width: 1200px) {
  .page-about .about-hero h1 {
    font-size: 58px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-dot::after {
    animation: none;
  }

  .page-about .about-why-card,
  .page-about .network-panel,
  .page-about .longterm-card,
  .page-about .cross-card,
  .page-about .about-region {
    transition: none;
  }
}