.page-about {
  --about-tint: #EDF1F8;
  --about-hair: rgba(11, 27, 58, 0.14);
  --about-soft: rgba(247, 244, 239, 0.72);
  display: block;
}

.page-about .about-section {
  position: relative;
  padding: clamp(54px, 8vw, 104px) 0;
}

.page-about .about-section--dark {
  background: linear-gradient(165deg, var(--navy) 0%, var(--navy-deep) 100%);
  color: var(--cloud);
}

.page-about .about-section--indigo {
  background: linear-gradient(150deg, var(--indigo) 0%, var(--navy-deep) 94%);
  color: var(--cloud);
}

.page-about .about-section--cloud {
  background: var(--cloud);
  color: var(--graphite);
}

.page-about .about-section--cloud + .about-section--cloud {
  border-top: 1px solid var(--about-hair);
}

/* ---------- 通用排版 ---------- */
.page-about .eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .about-section--cloud .eyebrow {
  color: var(--sky-deep);
}

.page-about h2 {
  margin: 10px 0 14px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 4.6vw, 44px);
  line-height: 1.12;
  letter-spacing: -0.02em;
}

.page-about h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(19px, 2.4vw, 23px);
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.page-about p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.78;
}

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

.page-about .lede {
  font-size: clamp(17px, 2vw, 20px);
  line-height: 1.7;
  color: rgba(247, 244, 239, 0.88);
  max-width: 46ch;
}

.page-about .about-head {
  max-width: 620px;
  margin-bottom: clamp(28px, 4vw, 46px);
}

.page-about .about-head__text {
  font-size: 16px;
  line-height: 1.75;
  color: rgba(247, 244, 239, 0.76);
}

.page-about .about-head--dark .about-head__text {
  color: rgba(247, 244, 239, 0.72);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  margin: 0 0 24px;
  font-size: 13px;
}

.page-about .about-crumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-crumbs li {
  color: rgba(247, 244, 239, 0.6);
}

.page-about .about-crumbs li + li::before {
  content: "/";
  margin-right: 8px;
  color: rgba(247, 244, 239, 0.34);
}

.page-about .about-crumbs a {
  color: var(--sky);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 220ms var(--ease), color 220ms var(--ease);
}

.page-about .about-crumbs a:hover,
.page-about .about-crumbs a:focus-visible {
  border-bottom-color: var(--flame);
}

.page-about .about-crumbs a:focus-visible {
  outline: 2px solid var(--sky);
  outline-offset: 3px;
}

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  overflow: hidden;
  padding-top: calc(var(--header-offset) + 28px);
  padding-bottom: clamp(58px, 8vw, 110px);
  background:
    radial-gradient(120% 100% at 94% 0%, rgba(255, 90, 31, 0.30), transparent 56%),
    radial-gradient(90% 80% at 0% 96%, rgba(30, 155, 255, 0.22), transparent 60%),
    linear-gradient(165deg, var(--navy) 0%, var(--navy-deep) 100%);
  color: var(--cloud);
}

.page-about .about-intro__cut {
  position: absolute;
  right: -14%;
  bottom: 12%;
  width: 74%;
  height: 58%;
  background: linear-gradient(150deg, rgba(255, 90, 31, 0.9), rgba(224, 54, 44, 0.12));
  clip-path: polygon(26% 0, 100% 0, 100% 100%, 0 100%);
  opacity: 0.42;
  pointer-events: none;
}

.page-about .about-intro__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 34px;
}

.page-about .about-hero__title {
  margin: 14px 0 18px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(36px, 8.6vw, 76px);
  line-height: 1.02;
  letter-spacing: -0.028em;
  max-width: 15ch;
}

.page-about .about-intro__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

/* ---------- 玻璃数据卡 ---------- */
.page-about .about-facts {
  background: var(--glass);
  border: 1px solid var(--glass-line);
  border-radius: var(--radius-card);
  padding: 22px 20px;
  box-shadow: var(--shadow-2);
  backdrop-filter: blur(10px);
  color: var(--cloud);
}

.page-about .about-facts__title {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold);
}

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

.page-about .fact-row {
  display: grid;
  gap: 2px;
  padding-bottom: 12px;
  border-bottom: 1px dashed rgba(255, 255, 255, 0.16);
}

.page-about .fact-row:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .fact-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 4vw, 32px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--flame);
}

.page-about .fact-label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--about-soft);
}

.page-about .about-facts__note {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px solid rgba(255, 255, 255, 0.16);
  font-size: 13px;
  line-height: 1.66;
  color: rgba(247, 244, 239, 0.7);
}

/* ---------- 平台在做什么 ---------- */
.page-about .about-what {
  position: relative;
  z-index: 1;
  margin-top: clamp(44px, 6vw, 76px);
  max-width: 800px;
}

.page-about .about-what h2 {
  max-width: 22ch;
}

.page-about .about-what p {
  color: rgba(247, 244, 239, 0.82);
}

/* ---------- 演进阶段 ---------- */
.page-about .stage-switch {
  position: relative;
}

.page-about .stage-track {
  display: flex;
  gap: 12px;
  padding: 4px 2px 16px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .stage-chip {
  --chip: var(--indigo);
  flex: 0 0 74%;
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 132px;
  padding: 18px 16px;
  border-radius: var(--radius-card);
  border: 1px solid var(--glass-line);
  border-top: 4px solid var(--chip);
  background: var(--glass);
  cursor: pointer;
  transition: transform 220ms var(--ease), border-color 220ms var(--ease), background 220ms var(--ease);
}

.page-about .stage-chip:hover {
  transform: translateY(-4px);
  border-color: var(--flame);
}

.page-about .stage-chip[for="about-stage-1"] { --chip: var(--navy); }
.page-about .stage-chip[for="about-stage-2"] { --chip: var(--indigo); }
.page-about .stage-chip[for="about-stage-3"] { --chip: var(--sky); }
.page-about .stage-chip[for="about-stage-4"] { --chip: var(--flame); }

.page-about .stage-chip__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .stage-chip__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.28;
  color: var(--cloud);
}

.page-about .stage-chip__hint {
  margin-top: auto;
  font-size: 13px;
  line-height: 1.5;
  color: rgba(247, 244, 239, 0.66);
}

.page-about #about-stage-1:checked ~ .stage-track .stage-chip[for="about-stage-1"],
.page-about #about-stage-2:checked ~ .stage-track .stage-chip[for="about-stage-2"],
.page-about #about-stage-3:checked ~ .stage-track .stage-chip[for="about-stage-3"],
.page-about #about-stage-4:checked ~ .stage-track .stage-chip[for="about-stage-4"] {
  background: var(--glass-strong);
  border-color: var(--flame);
  box-shadow: var(--shadow-1);
}

.page-about .stage-panels {
  margin-top: 16px;
}

.page-about .stage-panel {
  display: none;
  padding: 22px 20px;
  border-radius: var(--radius-card);
  background: rgba(7, 18, 41, 0.5);
  border: 1px solid var(--glass-line);
  border-left: 4px solid var(--gold);
}

.page-about .stage-panel h3 {
  color: var(--cloud);
}

.page-about .stage-panel p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(247, 244, 239, 0.78);
}

.page-about #about-stage-1:checked ~ .stage-panels > .stage-panel[data-stage="1"],
.page-about #about-stage-2:checked ~ .stage-panels > .stage-panel[data-stage="2"],
.page-about #about-stage-3:checked ~ .stage-panels > .stage-panel[data-stage="3"],
.page-about #about-stage-4:checked ~ .stage-panels > .stage-panel[data-stage="4"] {
  display: block;
}

.page-about .stage-foot {
  margin: 22px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(247, 244, 239, 0.62);
}

/* ---------- 图与说明 ---------- */
.page-about .figure {
  margin: 0;
}

.page-about .figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-card);
  object-fit: cover;
}

.page-about .figure__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: rgba(42, 47, 58, 0.66);
}

.page-about .about-section--dark .figure__caption,
.page-about .about-section--indigo .figure__caption {
  color: rgba(247, 244, 239, 0.64);
}

/* ---------- 团队 ---------- */
.page-about .team-head {
  display: grid;
  gap: 26px;
}

.page-about .team-figure img {
  border: 1px solid var(--about-hair);
}

.page-about .team-lead p {
  color: rgba(42, 47, 58, 0.78);
}

.page-about .team-cols {
  display: grid;
  gap: 18px;
  margin-top: clamp(30px, 4vw, 48px);
}

.page-about .team-col {
  padding: 22px 20px;
  border-radius: var(--radius-card);
  background: #fff;
  border: 1px solid var(--about-hair);
  box-shadow: var(--shadow-1);
  transition: transform 220ms var(--ease), border-color 220ms var(--ease);
}

.page-about .team-col:hover {
  transform: translateY(-4px);
  border-color: var(--flame);
}

.page-about .team-col__num {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(30px, 5vw, 42px);
  font-weight: 700;
  line-height: 1;
  color: var(--flame);
}

.page-about .team-col p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(42, 47, 58, 0.76);
}

.page-about .team-col--ops { border-top: 4px solid var(--sky); }
.page-about .team-col--data { border-top: 4px solid var(--flame); }
.page-about .team-col--design { border-top: 4px solid var(--jade); }

/* ---------- 覆盖规模 ---------- */
.page-about .cov-grid {
  display: grid;
  gap: 34px;
  align-items: start;
}

.page-about .cov-left > p {
  color: rgba(42, 47, 58, 0.78);
  max-width: 52ch;
}

.page-about .cov-gauge-row {
  display: grid;
  gap: 24px;
  align-items: center;
  margin: 26px 0 24px;
}

.page-about .cov-gauge {
  width: min(190px, 62vw);
  height: auto;
}

.page-about .cov-gauge__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 40px;
  font-weight: 700;
  fill: var(--navy);
}

.page-about .cov-gauge__cap {
  font-family: var(--font-body);
  font-size: 13px;
  fill: rgba(42, 47, 58, 0.7);
}

.page-about .cov-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 18px;
  margin: 0;
}

.page-about .cov-stat {
  padding-top: 12px;
  border-top: 2px solid var(--about-hair);
}

.page-about .cov-stat dt {
  font-size: 13px;
  line-height: 1.5;
  color: rgba(42, 47, 58, 0.68);
}

.page-about .cov-stat dd {
  margin: 4px 0 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(22px, 3.6vw, 30px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--navy);
}

.page-about .cov-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tag--onlight {
  display: inline-block;
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  font-size: 13px;
  line-height: 1.4;
  color: var(--navy);
  background: rgba(30, 155, 255, 0.12);
  border: 1px solid rgba(30, 155, 255, 0.3);
}

.page-about .cov-figure img {
  border: 1px solid var(--about-hair);
}

/* ---------- 合作方式 ---------- */
.page-about .partner-switch {
  position: relative;
}

.page-about .partner-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
}

.page-about .partner-tab {
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--about-hair);
  background: #fff;
  color: var(--navy);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  cursor: pointer;
  transition: background 220ms var(--ease), color 220ms var(--ease), border-color 220ms var(--ease);
}

.page-about .partner-tab:hover {
  border-color: var(--flame);
}

.page-about #about-partner-1:checked ~ .partner-tabs .partner-tab[for="about-partner-1"],
.page-about #about-partner-2:checked ~ .partner-tabs .partner-tab[for="about-partner-2"],
.page-about #about-partner-3:checked ~ .partner-tabs .partner-tab[for="about-partner-3"] {
  background: var(--flame);
  border-color: var(--flame);
  color: var(--navy);
}

.page-about .partner-panel {
  display: none;
  padding: 26px 22px;
  border-radius: var(--radius-card);
  background: #fff;
  border: 1px solid var(--about-hair);
  border-left: 4px solid var(--flame);
  box-shadow: var(--shadow-1);
}

.page-about .partner-panel p {
  font-size: 15px;
  line-height: 1.78;
  color: rgba(42, 47, 58, 0.78);
}

.page-about #about-partner-1:checked ~ .partner-panels > .partner-panel[data-partner="1"],
.page-about #about-partner-2:checked ~ .partner-panels > .partner-panel[data-partner="2"],
.page-about #about-partner-3:checked ~ .partner-panels > .partner-panel[data-partner="3"] {
  display: block;
}

.page-about .partner-panel__out {
  margin: 0;
  padding-top: 14px;
  border-top: 1px dashed var(--about-hair);
  font-size: 14px;
  color: rgba(42, 47, 58, 0.72);
}

.page-about .partner-panel__label {
  display: inline-block;
  margin-right: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--sky-deep);
}

.page-about .partner-cta {
  margin: 24px 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(42, 47, 58, 0.76);
}

.page-about .text-link {
  color: var(--sky-deep);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 220ms var(--ease);
}

.page-about .text-link:hover {
  color: var(--flame);
}

.page-about .text-link:focus-visible {
  outline: 2px solid var(--sky);
  outline-offset: 3px;
}

/* ---------- 长期价值 ---------- */
.page-about .why-grid {
  display: grid;
  gap: 18px;
}

.page-about .why-item {
  padding: 24px 20px;
  border-radius: var(--radius-card);
  background: var(--glass);
  border: 1px solid var(--glass-line);
  transition: transform 220ms var(--ease), border-color 220ms var(--ease);
}

.page-about .why-item:hover {
  transform: translateY(-4px);
  border-color: var(--flame);
}

.page-about .why-item__num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .why-item h3 {
  color: var(--cloud);
}

.page-about .why-item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(247, 244, 239, 0.76);
}

/* ---------- 收尾 ---------- */
.page-about .about-close {
  display: grid;
  gap: 30px;
  margin-top: clamp(40px, 6vw, 72px);
  padding-top: clamp(30px, 4vw, 52px);
  border-top: 1px solid rgba(255, 255, 255, 0.16);
}

.page-about .about-close__copy p {
  color: rgba(247, 244, 239, 0.78);
  max-width: 52ch;
}

.page-about .about-close__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.page-about .close-figure img {
  border: 1px solid var(--glass-line);
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .cov-gauge-row {
    grid-template-columns: auto minmax(0, 1fr);
    gap: 32px;
  }

  .page-about .cov-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px 26px;
  }

  .page-about .why-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px;
  }

  .page-about .stage-chip {
    flex: 0 0 46%;
  }
}

@media (min-width: 900px) {
  .page-about .about-intro__grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(268px, 0.72fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .about-facts {
    position: sticky;
    top: calc(var(--header-offset) + 22px);
    padding: 26px 24px;
  }

  .page-about .team-head {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 0.85fr);
    gap: 46px;
    align-items: center;
  }

  .page-about .team-cols {
    grid-template-columns: 0.85fr 1.3fr 0.9fr;
    gap: 22px;
    align-items: start;
  }

  .page-about .team-col--data {
    padding: 28px 24px;
  }

  .page-about .cov-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 54px;
    align-items: center;
  }

  .page-about .about-close {
    grid-template-columns: minmax(0, 1fr) 340px;
    gap: 56px;
    align-items: center;
  }

  .page-about .stage-track {
    overflow: visible;
    padding-bottom: 6px;
  }

  .page-about .stage-chip {
    flex: 1 1 0;
    min-width: 0;
  }
}

@media (min-width: 1180px) {
  .page-about .about-hero__title {
    font-size: 78px;
  }

  .page-about .stage-panel {
    padding: 28px 26px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage-chip,
  .page-about .team-col,
  .page-about .why-item,
  .page-about .about-crumbs a,
  .page-about .text-link,
  .page-about .partner-tab {
    transition: none;
  }

  .page-about .stage-chip:hover,
  .page-about .team-col:hover,
  .page-about .why-item:hover {
    transform: none;
  }
}