.page-about {
  --about-rail-w: 84px;
  --about-strong: rgba(20, 32, 43, 0.62);
  background-color: var(--abyss-900);
  overflow-x: clip;
}

.page-about h2 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.55rem, 3.4vw, 2.5rem);
  line-height: 1.14;
  letter-spacing: -0.005em;
  margin: 0;
}

.page-about h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.06rem;
  line-height: 1.35;
  margin: 0 0 0.5rem;
}

.page-about p {
  margin: 0;
}

.page-about .prose-lead {
  font-size: 1.02rem;
  line-height: 1.78;
  max-width: 40rem;
  color: inherit;
  opacity: 0.92;
}

.page-about .media-frame {
  margin: 2.25rem 0 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line-cyan);
  background: linear-gradient(140deg, var(--deep-800), var(--tide-700));
  line-height: 0;
}

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

.page-about .about-sec--paper .media-frame {
  border-color: rgba(20, 32, 43, 0.14);
  background: linear-gradient(140deg, var(--deep-800), var(--tide-700));
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  isolation: isolate;
  background-color: var(--abyss-900);
  padding-top: calc(var(--header-total) + clamp(2rem, 6vw, 4.25rem));
  padding-bottom: clamp(3rem, 7vw, 5.5rem);
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--line-strong), transparent);
  z-index: 2;
}

.page-about .hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(53, 230, 210, 0.09) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(53, 230, 210, 0.09) 1px, transparent 1px);
  background-size: 48px 48px;
  -webkit-mask-image: radial-gradient(120% 85% at 18% 8%, #000 26%, transparent 80%);
  mask-image: radial-gradient(120% 85% at 18% 8%, #000 26%, transparent 80%);
  pointer-events: none;
  z-index: 0;
}

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

.page-about .about-hero .crumbs {
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .crumbs-item + .crumbs-item::before {
  content: "/";
  margin: 0 0.5rem;
  opacity: 0.5;
}

.page-about .hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(2rem, 5vw, 3rem);
  align-items: start;
}

.page-about .hero-lead .eyebrow {
  color: var(--cyan-400);
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2rem, 4.6vw, 3.5rem);
  line-height: 1.05;
  letter-spacing: -0.012em;
  color: #fff;
  margin: 0.85rem 0 1.35rem;
  max-width: 22ch;
}

.page-about .about-hero .lede {
  font-size: 1.04rem;
  line-height: 1.78;
  color: var(--mist-200);
  max-width: 40rem;
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2rem;
}

.page-about .hero-panel {
  position: relative;
  background-color: rgba(20, 69, 107, 0.42);
  border: 1px solid var(--line-cyan);
  border-radius: var(--r-lg);
  padding: 1.5rem 1.4rem 1.25rem;
}

.page-about .hero-panel::before,
.page-about .hero-panel::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border: 1px solid var(--coral-500);
  opacity: 0.75;
}

.page-about .hero-panel::before {
  top: -1px;
  left: -1px;
  border-right: 0;
  border-bottom: 0;
  border-top-left-radius: var(--r-lg);
}

.page-about .hero-panel::after {
  bottom: -1px;
  right: -1px;
  border-left: 0;
  border-top: 0;
  border-bottom-right-radius: var(--r-lg);
}

.page-about .panel-title {
  font-size: 0.76rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan-400);
  margin-bottom: 1.1rem;
}

.page-about .team-stat-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem 1rem;
}

.page-about .team-stat-list li {
  border-left: 2px solid rgba(53, 230, 210, 0.35);
  padding-left: 0.75rem;
  min-height: 44px;
}

.page-about .stat-num {
  display: block;
  font-size: clamp(1.5rem, 3.2vw, 1.9rem);
  font-weight: 700;
  line-height: 1.1;
  color: #fff;
}

.page-about .stat-label {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.8rem;
  color: var(--slate-500);
}

.page-about .panel-foot {
  margin-top: 1.35rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--line-soft);
  font-size: 0.84rem;
  color: var(--mist-200);
  opacity: 0.85;
}

/* ---------- 区块骨架 ---------- */

.page-about .about-block {
  position: relative;
  padding: clamp(3rem, 7vw, 5.75rem) 0;
}

.page-about .about-sec--paper {
  background-color: var(--paper-100);
  color: var(--ink-900);
}

.page-about .about-sec--deep {
  background-color: var(--abyss-900);
  color: var(--mist-200);
  background-image:
    linear-gradient(to right, rgba(53, 230, 210, 0.06) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(53, 230, 210, 0.06) 1px, transparent 1px);
  background-size: 48px 48px;
}

.page-about .about-sec--tide {
  background-color: var(--deep-800);
  color: var(--mist-200);
}

.page-about .about-sec--abyss {
  background-color: var(--abyss-900);
  color: var(--mist-200);
}

.page-about .about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

.page-about .about-rail {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  padding-top: 0.7rem;
  border-top: 1px solid var(--line-cyan);
}

.page-about .about-sec--paper .about-rail {
  border-top-color: rgba(20, 32, 43, 0.18);
}

.page-about .about-rail .index-tag {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  color: var(--cyan-400);
}

.page-about .about-sec--paper .about-rail .index-tag {
  color: var(--tide-700);
}

.page-about .rail-name {
  font-size: 0.82rem;
  letter-spacing: 0.14em;
  opacity: 0.72;
}

.page-about .about-rail::after {
  content: "";
  display: none;
  width: 1px;
  height: 4.5rem;
  margin-top: 0.6rem;
  background: linear-gradient(to bottom, rgba(53, 230, 210, 0.5), transparent);
  flex: 0 0 auto;
}

.page-about .about-sec--paper .about-rail::after {
  background: linear-gradient(to bottom, rgba(20, 32, 43, 0.28), transparent);
}

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

.page-about .section-head {
  margin-bottom: 1.1rem;
}

.page-about .about-sec--paper .prose-lead {
  color: var(--about-strong);
}

/* ---------- 分工卡片 ---------- */

.page-about .duty-list {
  list-style: none;
  margin: 2.25rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.1rem;
}

.page-about .duty-item {
  background-color: #fff;
  border: 1px solid rgba(20, 32, 43, 0.1);
  border-radius: var(--r-md);
  padding: 1.4rem 1.35rem 1.5rem;
}

.page-about .duty-item p:last-child {
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--about-strong);
}

.page-about .duty-num {
  font-size: 1.9rem;
  font-weight: 700;
  line-height: 1;
  color: var(--tide-700);
  margin-bottom: 0.85rem;
}

/* ---------- 分段切换 ---------- */

.page-about .tabs {
  margin-top: 2.5rem;
}

.page-about .tablist {
  display: flex;
  gap: 0.55rem;
  overflow-x: auto;
  padding-bottom: 0.9rem;
  border-bottom: 1px solid var(--line-soft);
  scrollbar-width: thin;
}

.page-about .tab {
  flex: 0 0 auto;
  min-height: 44px;
  padding: 0.6rem 1.2rem;
  border-radius: var(--r-pill);
  border: 1px solid var(--line-cyan);
  background-color: transparent;
  color: var(--mist-200);
  font-family: var(--font-mono);
  font-size: 0.92rem;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: border-color 200ms var(--ease), color 200ms var(--ease), background-color 200ms var(--ease), transform 200ms var(--ease);
}

.page-about .tab:hover {
  border-color: var(--cyan-400);
  transform: translateY(-2px);
}

.page-about .tab[aria-selected="true"] {
  border-color: var(--coral-500);
  background-color: rgba(255, 107, 74, 0.1);
  color: var(--coral-500);
}

.page-about .tabpanel {
  margin-top: 1.6rem;
  max-width: 42rem;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--mist-200);
  animation: about-fade 200ms var(--ease);
}

.page-about .tabpanel[hidden] {
  display: none;
}

@keyframes about-fade {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* ---------- 节奏 ---------- */

.page-about .rhythm-list {
  list-style: none;
  margin: 2.5rem 0 0;
  padding: 1.6rem 0 0;
  border-top: 1px solid rgba(20, 32, 43, 0.16);
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

.page-about .rhythm-item {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.page-about .rhythm-head {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.page-about .rhythm-num {
  font-family: var(--font-mono);
  font-size: clamp(2.1rem, 4vw, 2.8rem);
  font-weight: 700;
  line-height: 1;
  color: var(--coral-500);
}

.page-about .rhythm-unit {
  font-size: 0.92rem;
  color: var(--tide-700);
}

.page-about .rhythm-desc {
  font-size: 0.95rem;
  line-height: 1.72;
  color: var(--about-strong);
}

.page-about .rhythm-note {
  margin-top: 2rem;
  padding-left: 1rem;
  border-left: 2px solid var(--cyan-400);
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--about-strong);
}

.page-about .rhythm-note a {
  color: var(--tide-700);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 服务覆盖 ---------- */

.page-about .coverage-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.75rem;
  margin-top: 2.25rem;
}

.page-about .coverage-layout .media-frame {
  margin-top: 0;
}

.page-about .coverage-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.9rem;
}

.page-about .coverage-item {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  padding: 1rem 1.15rem;
  border-radius: var(--r-md);
  border: 1px solid var(--line-cyan);
  background-color: rgba(6, 26, 46, 0.42);
  min-height: 44px;
}

.page-about .coverage-num {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 3.4vw, 2.1rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--cyan-400);
}

.page-about .coverage-num .plus {
  font-size: 0.7em;
  margin-left: 0.1em;
  color: var(--amber-400);
}

.page-about .coverage-label {
  font-size: 0.85rem;
  color: var(--mist-200);
  opacity: 0.86;
}

.page-about .coverage-note {
  margin-top: 1.75rem;
  max-width: 44rem;
  font-size: 0.98rem;
  line-height: 1.8;
  color: var(--mist-200);
}

/* ---------- 合作生态 ---------- */

.page-about .partner-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.1rem;
  margin-top: 2.25rem;
}

.page-about .partner-card {
  background-color: var(--paper-200);
  border-radius: var(--r-md);
  padding: 1.4rem 1.35rem 1.5rem;
  border-top: 2px solid var(--tide-700);
}

.page-about .partner-card p {
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--about-strong);
}

/* ---------- 结尾行动区 ---------- */

.page-about .about-cta {
  padding-bottom: clamp(3.5rem, 8vw, 7rem);
}

.page-about .cta-panel {
  position: relative;
  border: 1px solid var(--line-cyan);
  border-radius: var(--r-xl);
  padding: clamp(1.75rem, 5vw, 3rem);
  background-color: rgba(20, 69, 107, 0.32);
}

.page-about .cta-panel h2 {
  margin: 0.9rem 0 1.1rem;
  max-width: 26ch;
  color: #fff;
}

.page-about .cta-panel > p {
  max-width: 44rem;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--mist-200);
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.9rem;
}

.page-about .cta-links {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  margin: 1.75rem 0 0;
  padding: 1.1rem 0 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .cta-links a {
  font-size: 0.88rem;
  color: var(--mist-200);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 230, 210, 0.4);
  padding-bottom: 2px;
  transition: color 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .cta-links a:hover {
  color: var(--cyan-400);
  border-bottom-color: var(--cyan-400);
}

/* ---------- 断点 ---------- */

@media (min-width: 640px) {
  .page-about .duty-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-about .rhythm-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.75rem;
  }
}

@media (min-width: 860px) {
  .page-about .about-grid {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 2.5rem;
  }

  .page-about .about-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.9rem;
    padding-top: 0.9rem;
    position: sticky;
    top: calc(var(--header-total) + 2rem);
    align-self: start;
  }

  .page-about .about-rail::after {
    display: block;
  }

  .page-about .coverage-layout {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    align-items: start;
    gap: 2.25rem;
  }

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

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

@media (min-width: 960px) {
  .page-about .hero-grid {
    grid-template-columns: minmax(0, 13fr) minmax(0, 11fr);
    gap: 3.5rem;
  }

  .page-about .hero-panel {
    margin-top: 2.75rem;
  }

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

@media (min-width: 1200px) {
  .page-about .about-grid {
    gap: 3.25rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tab,
  .page-about .cta-links a {
    transition: none;
  }

  .page-about .tab:hover {
    transform: none;
  }

  .page-about .tabpanel {
    animation: none;
  }
}