/* ============================================================
   关于我们 · /about/
   叙事型页面：短段定位 → 阶段化叙述 → 对照边界 → 节奏收束
   ============================================================ */

.page-about {
  --about-hairline: 1px solid var(--color-line);
  --about-hairline-soft: 1px solid color-mix(in srgb, var(--color-line) 70%, transparent);
  --about-dot: 9px;
  --about-glow: 0 0 0 1px color-mix(in srgb, var(--color-primary) 55%, transparent),
                0 0 26px color-mix(in srgb, var(--color-primary) 26%, transparent);
  --about-glow-accent: 0 0 0 1px color-mix(in srgb, var(--color-accent) 60%, transparent),
                       0 0 24px color-mix(in srgb, var(--color-accent) 22%, transparent);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-1);
  padding-top: var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.02em;
  color: var(--color-ink-muted);
}

.page-about .breadcrumbs a {
  color: var(--color-ink-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 180ms ease, border-color 180ms ease;
}

.page-about .breadcrumbs a:hover,
.page-about .breadcrumbs a:focus-visible {
  color: var(--color-ink);
  border-bottom-color: var(--color-primary);
}

.page-about .breadcrumbs [aria-current="page"],
.page-about .breadcrumbs > span:last-child {
  color: var(--color-ink);
}

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

/* ---------- 通用小标题 ---------- */
.page-about .eyebrow {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

/* ============================================================
   1. 首屏：左文右图，错位构图
   ============================================================ */
.page-about .about-intro {
  padding-top: var(--space-6);
  padding-bottom: var(--section-y);
}

.page-about .about-intro__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-6);
  align-items: start;
}

.page-about .about-intro__title {
  margin: 0 0 var(--space-3);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: clamp(var(--text-3xl), 5.6vw, var(--text-4xl));
  line-height: var(--leading-heading);
  letter-spacing: -0.012em;
  color: var(--color-ink);
  max-width: 16ch;
}

.page-about .about-intro__lead {
  margin: 0 0 var(--space-3);
  max-width: var(--measure);
  font-size: var(--text-lg);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-about .about-intro__body {
  margin: 0 0 var(--space-4);
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .about-intro__facts {
  list-style: none;
  margin: 0;
  padding: var(--space-3) 0 0;
  border-top: var(--about-hairline);
  display: grid;
  gap: var(--space-2);
}

.page-about .about-intro__facts li {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

.page-about .about-intro__facts li::before {
  content: "";
  flex: none;
  width: 24px;
  height: 1px;
  background: var(--color-accent);
  transform: translateY(-4px);
}

.page-about .media {
  margin: 0;
  position: relative;
  overflow: hidden;
  border-radius: 0;
  border: var(--about-hairline);
  background: var(--color-surface-alt);
}

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

.page-about .media__caption {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-xs);
  line-height: 1.6;
  color: var(--color-ink-muted);
  border-top: var(--about-hairline-soft);
}

/* ============================================================
   2. 定位：是什么 / 不是什么
   ============================================================ */
.page-about .about-position {
  padding-block: var(--section-y);
  border-top: var(--about-hairline);
}

.page-about .about-position__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-4);
}

.page-about .about-position__h {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .about-position__body p {
  margin: 0 0 var(--space-3);
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .about-position__strong {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xl);
  line-height: 1.4;
  color: var(--color-ink) !important;
}

.page-about .about-position__pull {
  margin-top: var(--space-4) !important;
  padding-left: var(--space-3);
  border-left: var(--border-thick) solid var(--color-accent);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xl);
  line-height: 1.35;
  color: var(--color-ink) !important;
}

/* ============================================================
   3. 四代框架迭代：错位刻度轴
   ============================================================ */
.page-about .about-stages {
  padding-block: var(--section-y);
  border-top: var(--about-hairline);
}

.page-about .about-stages__head {
  max-width: var(--measure);
  margin-bottom: var(--space-4);
}

.page-about .about-stages__head h2 {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .about-stages__note {
  margin: 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .about-stages__band {
  margin: 0 0 var(--space-4);
  border: none;
  border-radius: 0;
  background: none;
}

.page-about .about-stages__band img {
  width: 100%;
  height: auto;
}

.page-about .about-stages__jump {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}

.page-about .about-stages__jump a {
  display: inline-block;
  padding: 6px var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-soft);
  text-decoration: none;
  border: var(--about-hairline);
  border-radius: var(--radius-pill);
  transition: color 180ms ease, border-color 180ms ease, box-shadow 220ms ease;
}

.page-about .about-stages__jump a:hover,
.page-about .about-stages__jump a:focus-visible {
  color: var(--color-ink);
  border-color: color-mix(in srgb, var(--color-primary) 70%, transparent);
  box-shadow: var(--about-glow);
}

.page-about .about-stages__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-6);
}

.page-about .about-stage {
  position: relative;
  padding-top: var(--space-4);
}

.page-about .about-stage::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 1px;
  background: var(--color-line);
}

.page-about .about-stage::after {
  content: "";
  position: absolute;
  top: calc(var(--about-dot) / -2 + 1px);
  left: 0;
  width: var(--about-dot);
  height: var(--about-dot);
  border-radius: 50%;
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-primary);
  box-shadow: var(--about-glow);
}

.page-about .about-stage__no {
  margin: 0 0 var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}

.page-about .about-stage__title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .about-stage__problem,
.page-about .about-stage__fix {
  margin: 0 0 var(--space-2);
  font-size: var(--text-sm);
  line-height: 1.7;
}

.page-about .about-stage__problem {
  color: var(--color-ink-muted);
}

.page-about .about-stage__fix {
  color: var(--color-ink-soft);
  padding-left: var(--space-2);
  border-left: var(--border-thin) solid var(--color-primary);
}

/* ============================================================
   4. 覆盖范围与统计口径
   ============================================================ */
.page-about .about-scope {
  padding-block: var(--section-y);
  border-top: var(--about-hairline);
}

.page-about .about-scope__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.page-about .about-scope__head h2 {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .about-scope__head p {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .about-scope__totals {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: var(--space-3);
  padding: var(--space-3) 0;
  border-top: var(--about-hairline);
  border-bottom: var(--about-hairline);
}

.page-about .about-scope__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: 1;
  color: var(--color-accent);
}

.page-about .about-scope__label {
  margin: var(--space-1) 0 0;
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

.page-about .about-scope__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .about-scope__item {
  padding: var(--space-3) 0;
  border-top: var(--about-hairline-soft);
}

.page-about .about-scope__name {
  margin: 0 0 var(--space-1);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1.3;
}

.page-about .about-scope__name a {
  color: var(--color-ink);
  text-decoration: none;
  border-bottom: 1px solid color-mix(in srgb, var(--color-primary) 55%, transparent);
  transition: border-color 180ms ease, color 180ms ease;
}

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

.page-about .about-scope__meta {
  margin: 0 0 var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}

.page-about .about-scope__desc {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}

/* ============================================================
   5. 边界：可切换的分组清单
   ============================================================ */
.page-about .about-boundary {
  padding-block: var(--section-y);
  border-top: var(--about-hairline);
}

.page-about .about-boundary__head {
  max-width: var(--measure);
  margin-bottom: var(--space-4);
}

.page-about .about-boundary__head h2 {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .about-boundary__head p {
  margin: 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .about-boundary__tabs .tablist {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  padding-bottom: var(--space-2);
  border-bottom: var(--about-hairline);
  margin-bottom: var(--space-3);
}

.page-about .about-boundary__tabs .tab {
  appearance: none;
  background: transparent;
  border: var(--about-hairline);
  border-radius: var(--radius-pill);
  padding: 8px var(--space-3);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  cursor: pointer;
  transition: color 180ms ease, border-color 180ms ease, box-shadow 220ms ease, background-color 180ms ease;
}

.page-about .about-boundary__tabs .tab:hover {
  color: var(--color-ink);
  border-color: color-mix(in srgb, var(--color-primary) 60%, transparent);
}

.page-about .about-boundary__tabs .tab[aria-selected="true"] {
  color: var(--color-ink);
  border-color: color-mix(in srgb, var(--color-accent) 65%, transparent);
  background: color-mix(in srgb, var(--color-highlight) 45%, transparent);
  box-shadow: var(--about-glow-accent);
}

.page-about .about-boundary__panel + .about-boundary__panel {
  margin-top: var(--space-4);
}

.page-about .about-boundary__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-3);
}

.page-about .about-boundary__list li {
  position: relative;
  padding-left: var(--space-4);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .about-boundary__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 16px;
  height: 1px;
  background: var(--color-primary);
}

/* ============================================================
   6. 运营节奏
   ============================================================ */
.page-about .about-rhythm {
  padding-block: var(--section-y);
  border-top: var(--about-hairline);
}

.page-about .about-rhythm__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-6);
  align-items: start;
}

.page-about .about-rhythm__text h2 {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .about-rhythm__intro {
  margin: 0 0 var(--space-4);
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

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

.page-about .about-rhythm__list li {
  padding: var(--space-3) 0;
  border-top: var(--about-hairline-soft);
  font-size: var(--text-sm);
  line-height: 1.75;
  color: var(--color-ink-soft);
}

.page-about .about-rhythm__list li:last-child {
  border-bottom: var(--about-hairline-soft);
}

.page-about .about-rhythm__media {
  border: var(--about-hairline);
}

/* ============================================================
   7. 合规与相邻入口（浅色对比区块收尾）
   ============================================================ */
.page-about .about-compliance {
  padding-bottom: var(--section-y-lg);
}

.page-about .about-compliance__box {
  padding: var(--space-6) var(--space-4);
  border-radius: var(--radius-md);
}

.page-about .about-compliance__h {
  margin: 0 0 var(--space-3);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  color: var(--color-contrast-ink);
  max-width: 22ch;
}

.page-about .about-compliance__p {
  margin: 0 0 var(--space-4);
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-contrast-ink);
}

.page-about .about-compliance__links {
  list-style: none;
  margin: 0 0 var(--space-4);
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .about-compliance__links li {
  padding: var(--space-2) 0;
  border-top: 1px solid var(--color-contrast-line);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-contrast-ink);
}

.page-about .about-compliance__links li:last-child {
  border-bottom: 1px solid var(--color-contrast-line);
}

.page-about .about-compliance__links a {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  color: var(--color-contrast-ink);
  text-decoration: none;
  border-bottom: 2px solid var(--color-contrast-accent);
  transition: color 180ms ease;
}

.page-about .about-compliance__links a:hover,
.page-about .about-compliance__links a:focus-visible {
  color: var(--color-contrast-accent);
}

.page-about .about-compliance__meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-contrast-accent);
}

/* ============================================================
   8. 响应式：≥760px 与 ≥1024px
   ============================================================ */
@media (min-width: 760px) {
  .page-about .about-intro__facts {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-3);
  }

  .page-about .about-position__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: var(--space-6);
    align-items: start;
  }

  .page-about .about-scope__grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
    gap: var(--space-6);
    align-items: end;
  }

  .page-about .about-scope__totals {
    border-top: none;
    border-bottom: none;
    padding: 0;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    border-left: var(--about-hairline);
    padding-left: var(--space-4);
  }

  .page-about .about-scope__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: var(--space-6);
  }

  .page-about .about-boundary__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: var(--space-6);
  }

  .page-about .about-compliance__box {
    padding: var(--space-8) var(--space-6);
  }

  .page-about .about-compliance__links {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    column-gap: var(--space-6);
  }
}

@media (min-width: 1024px) {
  .page-about .about-intro {
    padding-top: var(--space-8);
  }

  .page-about .about-intro__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: var(--space-8);
  }

  .page-about .about-intro__media {
    margin-top: var(--space-6);
  }

  .page-about .about-stages__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--space-4);
    align-items: start;
  }

  .page-about .about-stage:nth-child(2) {
    margin-top: 34px;
  }

  .page-about .about-stage:nth-child(3) {
    margin-top: 68px;
  }

  .page-about .about-stage:nth-child(4) {
    margin-top: 102px;
  }

  .page-about .about-rhythm__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: var(--space-8);
  }

  .page-about .about-rhythm__media {
    margin-top: var(--space-4);
  }
}

/* ============================================================
   9. 动效：仅服务定位，尊重减弱动效偏好
   ============================================================ */
@media (prefers-reduced-motion: no-preference) {
  .page-about [data-reveal] {
    opacity: 0;
    transform: translateY(14px);
    transition: opacity 420ms ease, transform 420ms ease;
  }

  .page-about [data-reveal].is-visible {
    opacity: 1;
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }

  .page-about [data-reveal] {
    opacity: 1;
    transform: none;
  }
}
</main>