.page-about {
  --about-sticky-top: calc(var(--header-h) + 28px);
  min-width: 0;
}

/* ==================== 首屏 ==================== */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  padding-block: clamp(72px, 11vw, 128px) clamp(52px, 8vw, 88px);
  background:
    radial-gradient(130% 100% at 88% 0%, rgba(14, 111, 224, 0.75), transparent 62%),
    radial-gradient(110% 90% at 2% 100%, rgba(79, 227, 208, 0.24), transparent 60%),
    var(--aurora-deep);
  color: var(--ice);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -30% -20% auto -20%;
  height: 78%;
  z-index: 0;
  pointer-events: none;
  background: conic-gradient(from 210deg at 32% 42%,
      rgba(79, 227, 208, 0.22),
      rgba(99, 180, 255, 0.16),
      transparent 62%);
  filter: blur(70px);
  animation: about-aurora 12s var(--ease) infinite alternate;
}

@keyframes about-aurora {
  from { transform: translate(-3%, 0) scale(1); }
  to   { transform: translate(4%, 3%) scale(1.08); }
}

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

.page-about .about-hero .breadcrumb {
  color: rgba(247, 250, 255, 0.7);
  font-size: 13px;
  margin-bottom: clamp(30px, 5vw, 46px);
}

.page-about .about-hero .breadcrumb a {
  color: inherit;
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.page-about .about-hero .breadcrumb a:hover {
  color: var(--aurora-cyan);
}

.page-about .about-hero .breadcrumb__sep {
  margin-inline: 8px;
  opacity: 0.5;
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(36px, 6vw, 60px);
  align-items: end;
}

.page-about .about-hero .eyebrow {
  color: var(--aurora-cyan);
  margin-bottom: 18px;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(34px, 5.4vw, 64px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: #fff;
  margin: 0 0 clamp(18px, 2.6vw, 26px);
  text-wrap: balance;
}

.page-about .about-hero__lead {
  font-size: clamp(16px, 1.5vw, 17.5px);
  line-height: 1.85;
  color: rgba(247, 250, 255, 0.8);
  max-width: 46ch;
  margin: 0 0 clamp(26px, 3.6vw, 34px);
}

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

.page-about .about-hero__metrics {
  display: grid;
  gap: 10px;
  align-content: end;
}

.page-about .about-metric {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 6px 18px;
  padding: clamp(15px, 2.2vw, 20px) clamp(16px, 2.4vw, 24px);
  border-radius: var(--radius-sm);
  background: rgba(247, 250, 255, 0.07);
  border: 1px solid rgba(99, 180, 255, 0.24);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: background var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              transform var(--dur) var(--ease);
}

.page-about .about-metric:hover {
  background: rgba(247, 250, 255, 0.12);
  border-color: var(--aurora-cyan);
  transform: translateX(5px);
}

.page-about .about-metric__value {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(20px, 2.2vw, 26px);
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: #fff;
}

.page-about .about-metric__label {
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: rgba(247, 250, 255, 0.6);
  white-space: nowrap;
}

/* ==================== 主体双栏 ==================== */
.page-about .about-body {
  background: var(--ice);
  padding-block: clamp(52px, 8vw, 96px) clamp(40px, 6vw, 72px);
}

.page-about .about-body__grid {
  display: grid;
  gap: clamp(28px, 5vw, 44px);
  min-width: 0;
}

/* 左侧导航（移动端为横向 chips，桌面端为粘性时间轴） */
.page-about .about-index {
  min-width: 0;
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  scrollbar-width: none;
}

.page-about .about-index__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-index__item {
  flex: none;
}

.page-about .about-index__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  border-radius: 999px;
  border: 1px solid var(--frost);
  background: #fff;
  color: var(--slate);
  font-size: 13.5px;
  font-weight: 500;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              background var(--dur) var(--ease);
}

.page-about .about-index__link:hover {
  color: var(--aurora);
  border-color: var(--aurora-light);
}

.page-about .about-index__link[aria-current="true"] {
  color: #fff;
  background: var(--aurora);
  border-color: var(--aurora);
}

.page-about .about-index__dot {
  display: none;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
  flex: none;
}

/* ==================== 内容流 ==================== */
.page-about .about-flow {
  display: grid;
  gap: clamp(52px, 7vw, 92px);
  min-width: 0;
}

.page-about .about-block {
  min-width: 0;
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .about-block__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 2.9vw, 33px);
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0 0 clamp(16px, 2.2vw, 22px);
  text-wrap: balance;
}

.page-about .about-block__prose p {
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--slate);
  margin: 0 0 18px;
}

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

/* 图片容器 */
.page-about .about-figure {
  margin: 0 0 clamp(24px, 3.4vw, 34px);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--frost);
  background: var(--aurora-deep);
  box-shadow: var(--shadow-1);
}

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

.page-about .about-figure--cover img { aspect-ratio: 12 / 7; }
.page-about .about-figure--team img { aspect-ratio: 7 / 4; }
.page-about .about-figure--phase img { aspect-ratio: 16 / 9; }

/* 区域分布条 */
.page-about .region-list {
  list-style: none;
  margin: 0 0 clamp(24px, 3.4vw, 32px);
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .region-list__item {
  display: grid;
  grid-template-columns: 4.2em minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  font-size: 14.5px;
}

.page-about .region-list__name {
  color: var(--ink);
  font-weight: 600;
}

.page-about .region-list__track {
  display: block;
  height: 8px;
  border-radius: 999px;
  background: var(--frost);
  overflow: hidden;
}

.page-about .region-list__fill {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--aurora), var(--aurora-cyan));
}

.page-about .region-list__item:nth-child(1) .region-list__fill { width: 100%; }
.page-about .region-list__item:nth-child(2) .region-list__fill { width: 76%; }
.page-about .region-list__item:nth-child(3) .region-list__fill { width: 61%; }
.page-about .region-list__item:nth-child(4) .region-list__fill { width: 49%; }

.page-about .region-list__note {
  font-size: 12.5px;
  letter-spacing: 0.02em;
  color: var(--slate);
  white-space: nowrap;
}

/* 数据小格 */
.page-about .stat-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: clamp(22px, 3vw, 30px);
}

.page-about .stat-cell {
  padding: 16px 18px;
  border-radius: var(--radius-md);
  background: #fff;
  border: 1px solid var(--frost);
  transition: border-color var(--dur) var(--ease),
              transform var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease);
}

.page-about .stat-cell:hover {
  border-color: var(--aurora-light);
  transform: translateY(-3px);
  box-shadow: var(--shadow-1);
}

.page-about .stat-cell__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(19px, 2.2vw, 24px);
  font-weight: 700;
  line-height: 1.15;
  color: var(--aurora);
}

.page-about .stat-cell__num--accent {
  color: var(--maple);
}

.page-about .stat-cell__label {
  display: block;
  margin-top: 6px;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--slate);
}

/* ==================== 版本演进时间轴 ==================== */
.page-about .phase-track {
  list-style: none;
  margin: 0 0 clamp(26px, 3.6vw, 36px);
  padding: 0;
  position: relative;
  display: grid;
  gap: clamp(18px, 2.6vw, 26px);
}

.page-about .phase-track::before {
  content: "";
  position: absolute;
  left: 16px;
  top: 14px;
  bottom: 14px;
  width: 2px;
  margin-left: -1px;
  border-radius: 2px;
  pointer-events: none;
  background: linear-gradient(180deg, var(--aurora), var(--aurora-cyan) 72%, transparent);
}

.page-about .phase {
  position: relative;
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  gap: clamp(12px, 1.8vw, 18px);
  align-items: start;
}

.page-about .phase__badge {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--ice);
  border: 2px solid var(--aurora-light);
  color: var(--aurora);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.02em;
  transition: background var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              color var(--dur) var(--ease);
}

.page-about .phase:hover .phase__badge {
  background: var(--maple);
  border-color: var(--maple);
  color: #fff;
}

.page-about .phase__body {
  position: relative;
  padding: clamp(16px, 2.4vw, 22px) clamp(18px, 2.6vw, 24px);
  background: #fff;
  border: 1px solid var(--frost);
  border-radius: 2px var(--radius-md) var(--radius-md) var(--radius-md);
  overflow: hidden;
  transition: transform var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}

.page-about .phase__body::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background: linear-gradient(180deg, var(--aurora), var(--aurora-cyan));
}

.page-about .phase:hover .phase__body {
  transform: translateY(-4px);
  border-color: var(--aurora-light);
  box-shadow: var(--shadow-2);
}

.page-about .phase__title {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(16.5px, 1.9vw, 18.5px);
  line-height: 1.4;
  color: var(--ink);
  margin: 0 0 8px;
}

.page-about .phase__year {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--maple);
}

.page-about .phase__text {
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--slate);
  margin: 0;
}

/* ==================== 团队 ==================== */
.page-about .team-split {
  display: grid;
  gap: clamp(22px, 3.2vw, 30px);
  margin-bottom: clamp(22px, 3vw, 30px);
}

.page-about .team-split__content {
  min-width: 0;
}

.page-about .team-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.page-about .team-cell {
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: #fff;
  border: 1px solid var(--frost);
  transition: border-color var(--dur) var(--ease),
              transform var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease);
}

.page-about .team-cell:hover {
  border-color: var(--aurora-light);
  transform: translateY(-3px);
  box-shadow: var(--shadow-1);
}

.page-about .team-cell__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.4vw, 26px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--aurora);
}

.page-about .team-cell__unit {
  font-family: var(--font-body);
  font-size: 0.5em;
  font-weight: 600;
  color: var(--slate);
  margin-left: 3px;
}

.page-about .team-cell__name {
  display: block;
  margin-top: 5px;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--slate);
}

/* 响应节奏表 */
.page-about .cadence {
  margin-top: clamp(22px, 3vw, 30px);
  border-top: 1px solid var(--frost);
}

.page-about .cadence__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 14px 4px;
  border-bottom: 1px solid var(--frost);
  transition: background var(--dur) var(--ease);
}

.page-about .cadence__row:hover {
  background: rgba(14, 111, 224, 0.04);
}

.page-about .cadence__when {
  font-family: var(--font-mono);
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--maple);
}

.page-about .cadence__what {
  font-size: 15px;
  line-height: 1.7;
  color: var(--slate);
}

/* ==================== 合作生态 ==================== */
.page-about .eco-grid {
  display: grid;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .eco-card {
  position: relative;
  overflow: hidden;
  padding: clamp(18px, 2.4vw, 24px);
  border-radius: var(--radius-md);
  background: #fff;
  border: 1px solid var(--frost);
  transition: border-color var(--dur) var(--ease),
              transform var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease);
}

.page-about .eco-card::after {
  content: "";
  position: absolute;
  right: -30%;
  bottom: -60%;
  width: 140px;
  height: 140px;
  border-radius: 50%;
  pointer-events: none;
  background: radial-gradient(circle, rgba(79, 227, 208, 0.35), transparent 68%);
}

.page-about .eco-card:hover {
  border-color: var(--aurora-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-2);
}

.page-about .eco-card__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 2.6vw, 30px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--aurora);
}

.page-about .eco-card__num--accent {
  color: var(--maple);
}

.page-about .eco-card__title {
  display: block;
  margin-top: 6px;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .eco-card__desc {
  position: relative;
  z-index: 1;
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--slate);
}

/* ==================== 底部 CTA ==================== */
.page-about .about-cta {
  background: var(--ice);
  padding-block: 0 clamp(56px, 9vw, 96px);
}

.page-about .about-cta__card {
  position: relative;
  overflow: hidden;
  display: grid;
  gap: clamp(20px, 3vw, 28px);
  padding: clamp(28px, 4.6vw, 52px);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-2);
  color: var(--ice);
  background:
    radial-gradient(120% 140% at 92% 0%, rgba(14, 111, 224, 0.55), transparent 60%),
    radial-gradient(100% 130% at 0% 100%, rgba(79, 227, 208, 0.22), transparent 58%),
    var(--aurora-deep);
}

.page-about .about-cta__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 2.6vw, 30px);
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: #fff;
  margin: 0 0 10px;
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 52ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(247, 250, 255, 0.78);
}

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

.page-about a:focus-visible,
.page-about button:focus-visible {
  outline: 2px solid var(--aurora-light);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ==================== 断点 ==================== */
@media (min-width: 640px) {
  .page-about .cadence__row {
    grid-template-columns: 11em minmax(0, 1fr);
    gap: 16px;
    align-items: baseline;
  }
}

@media (min-width: 720px) {
  .page-about .stat-row {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .eco-grid {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }

  .page-about .eco-card--a { grid-column: span 3; }
  .page-about .eco-card--b { grid-column: span 3; }
  .page-about .eco-card--c { grid-column: span 2; }
  .page-about .eco-card--d { grid-column: span 4; }
}

@media (min-width: 880px) {
  .page-about .about-cta__card {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.82fr);
    gap: clamp(40px, 5vw, 76px);
  }

  .page-about .about-metric:nth-child(2) { margin-inline-start: 10%; }
  .page-about .about-metric:nth-child(3) { margin-inline-start: 20%; }

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

@media (min-width: 1000px) {
  .page-about .about-body__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: clamp(40px, 5vw, 76px);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: var(--about-sticky-top);
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding: 0;
    border-left: 1px solid var(--frost);
  }

  .page-about .about-index__link {
    display: flex;
    width: 100%;
    position: relative;
    padding: 13px 12px 13px 22px;
    border: 0;
    border-radius: 0;
    background: transparent;
    font-size: 14px;
  }

  .page-about .about-index__link:hover {
    color: var(--aurora);
    background: rgba(14, 111, 224, 0.05);
  }

  .page-about .about-index__link[aria-current="true"] {
    color: var(--aurora);
    background: transparent;
    font-weight: 700;
  }

  .page-about .about-index__dot {
    display: block;
    position: absolute;
    left: -4.5px;
    top: 50%;
    transform: translateY(-50%);
    background: var(--frost);
    transition: background var(--dur) var(--ease),
                box-shadow var(--dur) var(--ease);
  }

  .page-about .about-index__link[aria-current="true"] .about-index__dot {
    background: var(--maple);
    box-shadow: 0 0 0 4px rgba(214, 40, 40, 0.16);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-hero::before {
    animation: none;
  }

  .page-about .about-metric,
  .page-about .phase__badge,
  .page-about .phase__body,
  .page-about .team-cell,
  .page-about .eco-card,
  .page-about .stat-cell,
  .page-about .about-index__link {
    transition: none;
  }
}