.page-about {
  --about-rule: color-mix(in srgb, var(--color-ink) 14%, transparent);
  --about-rule-deep: var(--color-contrast-line);
}

/* ---------- 通用排版 ---------- */
.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  margin: 0;
}

.page-about h2 {
  font-size: var(--text-xl);
  color: var(--color-ink);
  max-width: 22ch;
}

.page-about h3 {
  font-size: var(--text-lg);
  color: inherit;
  max-width: 20ch;
}

.page-about .surface-contrast h2,
.page-about .surface-contrast h3 {
  color: var(--color-contrast-ink);
}

.page-about p {
  margin: 0 0 var(--space-2);
}

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

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  margin-bottom: var(--space-6);
}

/* ---------- 开场 ---------- */
.page-about .about-intro-grid {
  display: grid;
  gap: var(--space-6);
}

.page-about .about-intro h1 {
  font-size: var(--text-3xl);
  color: var(--color-ink);
  margin: var(--space-2) 0 var(--space-3);
  max-width: 16ch;
}

.page-about .about-intro .lede {
  max-width: 42ch;
  color: var(--color-ink-soft);
  font-size: var(--text-lg);
  line-height: 1.42;
}

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

.page-about .about-intro-body p {
  color: var(--color-ink-soft);
}

.page-about .about-intro-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-4);
}

.page-about .figure-media {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-sm);
  background: var(--color-surface-deep);
}

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

.page-about .about-intro-figure .figure-media {
  aspect-ratio: 13 / 9;
}

.page-about .figure-caption {
  margin-top: var(--space-2);
  color: var(--color-ink-muted);
  font-size: var(--text-sm);
  max-width: 46ch;
}

.page-about .figure-overlay {
  position: absolute;
  inset: auto 0 0 0;
  padding: var(--space-4);
  background: var(--overlay-scrim);
  color: var(--color-primary-ink);
  font-size: var(--text-sm);
  line-height: 1.5;
}

.page-about .figure-overlay p {
  margin: 0;
}

/* ---------- 为什么做这件事 ---------- */
.page-about .why-layout {
  display: grid;
  gap: var(--space-4);
}

.page-about .why-body > p {
  color: var(--color-ink-soft);
  max-width: 66ch;
}

.page-about .why-list {
  list-style: none;
  margin: var(--space-4) 0 0;
  padding: 0;
  display: grid;
  gap: var(--space-2);
}

.page-about .why-list li {
  position: relative;
  padding: var(--space-3) var(--space-3) var(--space-3) var(--space-6);
  background: var(--color-surface);
  border-radius: var(--radius-sm);
}

.page-about .why-list li::before {
  content: "";
  position: absolute;
  left: var(--space-3);
  top: calc(var(--space-3) + 6px);
  width: 12px;
  height: 12px;
  background: var(--color-accent);
}

.page-about .why-key {
  display: block;
  font-size: var(--text-sm);
  letter-spacing: 0.12em;
  color: var(--color-accent);
  margin-bottom: var(--space-1);
}

.page-about .why-list p {
  color: var(--color-ink-soft);
  max-width: 62ch;
}

.page-about .why-list a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 团队与服务能力 ---------- */
.page-about .team-head {
  max-width: 62ch;
}

.page-about .team-lede {
  margin-top: var(--space-3);
  color: var(--color-ink-soft);
}

.page-about .cap-grid {
  display: grid;
  gap: var(--space-3);
  margin-top: var(--space-6);
}

.page-about .cap-block {
  padding: var(--space-4);
  border-radius: var(--radius-sm);
}

.page-about .cap-block h3 {
  margin-bottom: var(--space-3);
}

.page-about .cap-block p {
  color: inherit;
}

.page-about .cap-block--primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}

.page-about .cap-block--flat {
  background: var(--color-surface-alt);
  color: var(--color-ink);
}

.page-about .cap-block--accent {
  background: var(--color-accent);
  color: var(--color-accent-ink);
}

.page-about .cap-num {
  font-size: var(--text-2xl);
  line-height: 1;
  letter-spacing: 0.04em;
  margin: 0 0 var(--space-3);
  opacity: 0.92;
}

.page-about .cap-roster {
  margin: 0;
  display: grid;
  gap: var(--space-2);
}

.page-about .cap-roster > div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-3);
}

.page-about .cap-roster dt {
  font-size: var(--text-base);
  opacity: 0.86;
}

.page-about .cap-roster dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-base);
  letter-spacing: 0.04em;
}

.page-about .cap-scope {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-1);
}

.page-about .cap-scope li {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-base);
}

.page-about .cap-scope li::before {
  content: "";
  flex: none;
  width: 8px;
  height: 8px;
  background: currentColor;
  opacity: 0.7;
}

.page-about .team-figure {
  margin: var(--space-6) 0 0;
  max-width: 100%;
}

.page-about .team-figure .figure-media {
  aspect-ratio: 3 / 2;
  background: var(--color-surface-alt);
}

/* ---------- 五个阶段 ---------- */
.page-about .stages {
  color: var(--color-contrast-ink);
}

.page-about .stages .eyebrow {
  color: var(--color-contrast-accent);
}

.page-about .stages-head {
  max-width: 60ch;
}

.page-about .stages-layout {
  display: grid;
  gap: var(--space-6);
  margin-top: var(--space-6);
}

.page-about .stages-list {
  display: grid;
}

.page-about .stage-row {
  border-top: 1px solid var(--about-rule-deep);
  padding: var(--space-3) 0;
}

.page-about .stage-row:last-child {
  border-bottom: 1px solid var(--about-rule-deep);
}

.page-about .stage-summary {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: var(--space-3);
  cursor: pointer;
  list-style: none;
}

.page-about .stage-summary::-webkit-details-marker {
  display: none;
}

.page-about .stage-summary::marker {
  content: "";
}

.page-about .stage-num {
  font-size: var(--text-lg);
  letter-spacing: 0.04em;
  color: var(--color-contrast-accent);
}

.page-about .stage-name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}

.page-about .stage-toggle {
  width: 12px;
  height: 12px;
  background: var(--color-contrast-accent);
  border-radius: var(--radius-sm);
  opacity: 0.45;
  transition: opacity 200ms linear;
}

.page-about .stage-row[open] .stage-toggle {
  opacity: 1;
}

.page-about .stage-summary:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 4px;
}

.page-about .stage-body {
  padding: var(--space-2) 0 0 calc(var(--space-6) + var(--space-1));
}

.page-about .stage-body p {
  margin: 0;
  color: color-mix(in srgb, var(--color-contrast-ink) 84%, transparent);
  max-width: 60ch;
}

.page-about .stages-figure {
  margin: 0;
}

.page-about .stages-figure .figure-media {
  aspect-ratio: 11 / 7;
  background: color-mix(in srgb, var(--color-contrast-ink) 12%, transparent);
}

/* ---------- 合作与下一步 ---------- */
.page-about .partner-layout {
  display: grid;
  gap: var(--space-6);
}

.page-about .partner-text > p {
  margin-top: var(--space-3);
  color: var(--color-ink-soft);
  max-width: 58ch;
}

.page-about .partner-steps {
  display: grid;
  gap: var(--gutter);
}

.page-about .partner-step {
  display: grid;
  gap: var(--space-1);
  padding: var(--space-4);
  background: var(--color-surface-alt);
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--color-ink);
  transition: background-color 200ms linear;
}

.page-about .partner-step:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.page-about .partner-step-title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  letter-spacing: var(--tracking-heading);
}

.page-about .partner-step-text {
  color: var(--color-ink-soft);
  font-size: var(--text-sm);
  line-height: 1.6;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .why-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 820px) {
  .page-about .cap-grid {
    grid-template-columns: repeat(7, minmax(0, 1fr));
    gap: var(--gutter);
    align-items: start;
  }

  .page-about .cap-block:nth-child(1) {
    grid-column: 1 / span 4;
  }

  .page-about .cap-block:nth-child(2) {
    grid-column: 5 / span 3;
    margin-top: var(--space-6);
  }

  .page-about .cap-block:nth-child(3) {
    grid-column: 2 / span 4;
    margin-top: var(--space-4);
  }

  .page-about .team-figure {
    max-width: 640px;
    margin-left: auto;
  }
}

@media (min-width: 960px) {
  .page-about .about-intro-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: var(--space-8);
    align-items: start;
  }

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

  .page-about .stages-layout {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: var(--space-8);
    align-items: start;
  }

  .page-about .partner-layout {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: var(--space-8);
    align-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition: none !important;
    animation: none !important;
  }
}