.page-about {
  --about-cut: 22px;
  --about-gap: clamp(48px, 6vw, 88px);
}

/* ===== 首屏 ===== */
.page-about .about-hero {
  padding: clamp(24px, 4vw, 48px) 0 clamp(40px, 6vw, 72px);
}

.page-about .about-hero-head {
  margin-top: clamp(28px, 5vw, 56px);
}

.page-about .about-title {
  margin: 14px 0 0;
  font-size: clamp(40px, 7vw, 96px);
  font-weight: 200;
  letter-spacing: -0.025em;
  line-height: 1.02;
  color: var(--fog);
}

.page-about .about-title-main {
  display: block;
}

.page-about .about-title-sub {
  display: block;
  margin-top: 16px;
  font-size: clamp(15px, 1.6vw, 20px);
  font-weight: 400;
  letter-spacing: 0.01em;
  line-height: 1.65;
  color: var(--fog);
  opacity: 0.66;
  max-width: 30ch;
}

.page-about .about-hero-grid {
  display: grid;
  gap: 28px;
  margin-top: clamp(28px, 4vw, 48px);
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: end;
  }
}

.page-about .about-hero-grid .lede {
  margin: 0;
  max-width: 46ch;
}

.page-about .about-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 20px;
}

.page-about .about-fact {
  border-top: 1px solid var(--line);
  padding-top: 12px;
}

.page-about .about-fact-value {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 500;
  line-height: 1.1;
  color: var(--lime);
}

.page-about .about-fact-label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  line-height: 1.55;
  color: var(--stone);
}

.page-about .about-hero-media {
  margin: clamp(32px, 5vw, 56px) 0 0;
}

/* ===== 主体骨架：窄栏索引 + 宽内容区 ===== */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
  padding-bottom: clamp(48px, 7vw, 96px);
}

@media (min-width: 940px) {
  .page-about .about-body {
    grid-template-columns: 196px minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }
}

.page-about .about-aside {
  border-top: 1px solid var(--line-soft);
  padding-top: 16px;
}

@media (min-width: 940px) {
  .page-about .about-aside {
    position: sticky;
    top: 88px;
    border-top: 0;
    padding-top: 0;
  }
}

.page-about .about-index {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

@media (min-width: 940px) {
  .page-about .about-index {
    display: block;
    overflow: visible;
    border-left: 1px solid var(--line-soft);
  }
}

.page-about .about-index a {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  font-size: 14px;
  line-height: 1.4;
  color: var(--stone);
  text-decoration: none;
  white-space: nowrap;
  border: 1px solid var(--line-soft);
  transition: color 0.22s var(--ease), border-color 0.22s var(--ease), background 0.22s var(--ease);
}

@media (min-width: 940px) {
  .page-about .about-index a {
    padding: 7px 0 7px 14px;
    border: 0;
    border-left: 1px solid transparent;
    margin-left: -1px;
    white-space: normal;
  }
  .page-about .about-index a:hover,
  .page-about .about-index a:focus-visible {
    color: var(--lime);
    border-left-color: var(--lime);
  }
}

.page-about .about-index a:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: 2px;
}

.page-about .idx-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--blue);
}

/* ===== 章节 ===== */
.page-about .about-sec {
  border-top: 1px solid var(--line-soft);
  padding: clamp(36px, 5vw, 64px) 0;
  scroll-margin-top: 96px;
}

.page-about .about-sec:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-h2 {
  margin: 10px 0 0;
  font-size: clamp(24px, 3.2vw, 38px);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--fog);
  max-width: 24ch;
}

.page-about .about-h3 {
  margin: 0 0 12px;
  font-size: clamp(18px, 2vw, 22px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--fog);
}

.page-about .about-cols {
  display: grid;
  gap: 26px;
  margin-top: clamp(20px, 3vw, 32px);
}

@media (min-width: 840px) {
  .page-about .about-cols {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    gap: clamp(24px, 4vw, 52px);
    align-items: start;
  }
}

.page-about .about-prose {
  margin-top: clamp(18px, 2.5vw, 28px);
}

.page-about .about-cols .about-prose {
  margin-top: 0;
}

.page-about .about-prose p {
  margin: 0 0 16px;
  font-size: clamp(16px, 1.15vw, 17px);
  line-height: 1.78;
  color: var(--fog);
  max-width: 46ch;
}

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

.page-about .about-prose--wide p {
  max-width: 62ch;
}

.page-about .about-note {
  background: var(--graphite);
  padding: 20px 26px 20px 20px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .about-note--lime {
  border-left: 2px solid var(--lime);
}

.page-about .about-note-title {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--lime);
}

.page-about .about-note p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--stone);
  max-width: 34ch;
}

.page-about .about-note-actions {
  margin-top: 16px;
}

/* ===== 覆盖范围分层列表 ===== */
.page-about .about-layers {
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-layer {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  background: var(--graphite);
  border-left: 2px solid var(--blue);
  transition: border-color 0.24s var(--ease), background 0.24s var(--ease), transform 0.24s var(--ease);
}

.page-about .about-layer:hover,
.page-about .about-layer:focus-within {
  border-left-color: var(--lime);
  background: rgba(182, 255, 59, 0.07);
  transform: translateX(4px);
}

.page-about .about-layer--sum {
  border-left-color: var(--gold);
}

.page-about .about-layer-idx {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  color: var(--blue);
}

.page-about .about-layer--sum .about-layer-idx {
  color: var(--gold);
}

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

.page-about .about-layer-name {
  display: block;
  font-size: 15px;
  font-weight: 700;
  color: var(--fog);
  line-height: 1.4;
}

.page-about .about-layer-desc {
  display: block;
  margin-top: 4px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--stone);
}

.page-about .about-layer-tag {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  color: var(--stone);
  white-space: nowrap;
}

.page-about .about-cover-media {
  margin: 0;
}

/* ===== 代际切换 ===== */
.page-about .about-tabs {
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .about-tabpanel {
  margin-top: 18px;
  padding: 24px 28px 24px 24px;
  background: var(--carbon);
  border-left: 2px solid var(--lime);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, 0 100%);
}

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

.page-about .about-tabpanel p {
  margin: 0;
  font-size: clamp(15px, 1.1vw, 17px);
  line-height: 1.78;
  color: var(--fog);
  max-width: 58ch;
}

.page-about .about-ticks {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

@media (min-width: 620px) {
  .page-about .about-ticks {
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  }
}

.page-about .about-ticks li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--stone);
}

.page-about .about-ticks li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 8px;
  height: 2px;
  background: var(--lime);
}

/* ===== 团队与流程 ===== */
.page-about .about-steps {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

@media (min-width: 780px) {
  .page-about .about-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
  }
}

.page-about .about-step {
  border-top: 1px solid var(--line);
  padding-top: 12px;
}

.page-about .about-step-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--blue);
}

.page-about .about-step-name {
  display: block;
  margin-top: 6px;
  font-size: 15px;
  font-weight: 700;
  color: var(--fog);
}

.page-about .about-step-desc {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--stone);
}

.page-about .about-team-media {
  margin: clamp(28px, 4vw, 44px) 0 0;
}

/* ===== 栏目卡片 ===== */
.page-about .about-cards {
  display: grid;
  gap: 16px;
  margin-top: clamp(22px, 3vw, 30px);
}

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

.page-about .about-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px 26px 22px 22px;
  background: var(--graphite);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, 0 100%);
  transition: background 0.24s var(--ease);
}

.page-about .about-card:hover {
  background: rgba(63, 125, 255, 0.12);
}

.page-about .about-card-title {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  color: var(--fog);
}

.page-about .about-card-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--stone);
}

.page-about .about-inline-link {
  margin: clamp(20px, 3vw, 28px) 0 0;
  font-size: 15px;
}

/* ===== 收束行动区 ===== */
.page-about .about-cta {
  margin-top: clamp(36px, 5vw, 64px);
  padding: clamp(28px, 4vw, 48px) clamp(22px, 3vw, 40px);
  background: linear-gradient(115deg, rgba(20, 49, 94, 0.85) 0%, rgba(15, 19, 25, 0.95) 62%);
  border-left: 2px solid var(--lime);
  clip-path: polygon(0 0, calc(100% - 34px) 0, 100% 34px, 100% 100%, 0 100%);
}

.page-about .about-cta-title {
  margin: 0;
  font-size: clamp(22px, 2.8vw, 32px);
  font-weight: 800;
  line-height: 1.28;
  color: var(--fog);
  max-width: 22ch;
}

.page-about .about-cta-text {
  margin: 14px 0 0;
  font-size: clamp(15px, 1.1vw, 17px);
  line-height: 1.72;
  color: var(--stone);
  max-width: 48ch;
}

.page-about .about-cta-actions {
  margin: 24px 0 0;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-layer,
  .page-about .about-card {
    transition: none;
    transform: none;
  }
}