.page-about {
  --about-gap: clamp(64px, 8vw, 132px);
  --about-pad: clamp(24px, 3.4vw, 48px);
  background: var(--snow-white);
  color: var(--graphite);
  font-family: var(--font-body);
  line-height: 1.85;
}

.page-about .about-shell {
  padding-bottom: 160px;
}

/* 首屏 */
.page-about .about-head {
  padding-top: clamp(48px, 7vw, 104px);
  padding-bottom: clamp(40px, 5vw, 76px);
  max-width: 46em;
}

.page-about .about-head__crumb {
  margin-bottom: 22px;
}

.page-about .page-head__title {
  font-family: var(--font-head);
  font-weight: 600;
  letter-spacing: 0.02em;
}

.page-about .page-head__lede {
  max-width: 36em;
}

/* 布局：左侧索引 + 主内容 */
.page-about .about-layout {
  align-items: start;
}

.page-about .about-body {
  display: grid;
  gap: var(--about-gap);
  min-width: 0;
}

/* 竖向索引 */
.page-about .about-rail {
  padding-left: 18px;
  border-left: 1px solid var(--glacier-300);
}

.page-about .about-rail .rail__title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--mist);
  margin-bottom: 18px;
}

.page-about .about-rail .rail__list {
  display: grid;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-rail__link {
  display: grid;
  gap: 2px;
  padding: 8px 0 8px 12px;
  border-left: 2px solid transparent;
  text-decoration: none;
  transition: border-color 160ms var(--ease), background-color 160ms var(--ease);
}

.page-about .about-rail__link .rail__code {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--glacier-700);
}

.page-about .about-rail__name {
  font-family: var(--font-head);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.page-about .about-rail__link:hover {
  background: var(--glacier-050);
}

.page-about .about-rail__link[aria-current] {
  border-left-color: var(--prayer-orange);
  background: var(--glacier-050);
}

.page-about .about-rail__link[aria-current] .rail__code {
  color: var(--prayer-orange);
}

/* 区块基础 */
.page-about .about-section {
  min-width: 0;
  scroll-margin-top: calc(var(--bar-h) + 24px);
}

.page-about .about-section--tint {
  background: var(--glacier-050);
  padding: var(--about-pad);
}

.page-about .about-section--green {
  background: var(--ink-green-050);
  padding: var(--about-pad);
}

.page-about .about-section--hold {
  border-left: 3px solid var(--prayer-orange);
  padding-left: clamp(20px, 3.6vw, 44px);
}

.page-about .about-lede {
  margin-top: 26px;
  max-width: 38em;
}

.page-about .about-lede p + p {
  margin-top: 18px;
}

/* 时间轴节点 */
.page-about .about-axis {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 0;
  margin-top: clamp(40px, 5vw, 64px);
  border-top: 1px solid var(--glacier-300);
  padding-top: 26px;
}

.page-about .about-axis__node {
  position: relative;
  display: grid;
  gap: 3px;
  padding: 0 18px 18px 0;
  border-bottom: 1px solid transparent;
  transition: border-color 160ms var(--ease);
}

.page-about .about-axis__node::before {
  content: "";
  position: absolute;
  top: -30px;
  left: 0;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--glacier-500);
  transition: background-color 160ms var(--ease), transform 160ms var(--ease);
}

.page-about .about-axis__node:hover,
.page-about .about-axis__node:focus-visible {
  border-bottom-color: var(--prayer-orange);
  outline: none;
}

.page-about .about-axis__node:hover::before,
.page-about .about-axis__node:focus-visible::before {
  background: var(--prayer-orange);
  transform: scale(1.5);
}

.page-about .about-axis__year {
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--glacier-700);
}

.page-about .about-axis__meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--mist);
  opacity: 0.75;
  transition: opacity 160ms var(--ease), color 160ms var(--ease);
}

.page-about .about-axis__node:hover .about-axis__meta,
.page-about .about-axis__node:focus-visible .about-axis__meta {
  opacity: 1;
  color: var(--glacier-700);
}

/* 图片容器细调 */
.page-about .about-media {
  margin: clamp(32px, 4vw, 56px) 0 0;
}

.page-about .about-media .media-frame__cap {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .about-media--lead {
  margin-top: clamp(40px, 5vw, 64px);
}

.page-about .about-media--team {
  margin-top: 32px;
  margin-bottom: 8px;
}

/* 团队折叠条目 */
.page-about .about-team {
  margin-top: 28px;
  border-top: 1px solid var(--glacier-300);
}

.page-about .about-member {
  border-bottom: 1px solid var(--glacier-300);
}

.page-about .about-member__sum {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 4px;
  cursor: pointer;
  list-style: none;
  transition: background-color 160ms var(--ease), padding-left 160ms var(--ease);
}

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

.page-about .about-member__sum::marker {
  content: "";
}

.page-about .about-member__sum:hover {
  background: var(--snow-white);
  padding-left: 12px;
}

.page-about .about-member__sum:focus-visible {
  outline: 2px solid var(--prayer-orange);
  outline-offset: 2px;
}

.page-about .about-member__name {
  font-family: var(--font-head);
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--glacier-700);
}

.page-about .about-member__count {
  font-size: 0.8125rem;
  color: var(--prayer-orange);
  flex: 0 0 auto;
}

.page-about .about-member__body {
  padding: 0 4px 22px;
}

.page-about .about-member__body p {
  max-width: 38em;
  color: var(--graphite);
}

/* 工序步骤 */
.page-about .about-flow {
  list-style: none;
  margin: clamp(32px, 4vw, 48px) 0 0;
  padding: 0;
  border-top: 1px solid var(--glacier-300);
}

.page-about .about-flow__step {
  display: grid;
  grid-template-columns: 46px 1fr;
  gap: 0 20px;
  align-items: start;
  padding: 22px 0;
  border-bottom: 1px solid var(--glacier-300);
}

.page-about .about-flow__no {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--glacier-500);
  padding-top: 4px;
}

.page-about .about-flow__t {
  font-family: var(--font-head);
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--glacier-700);
  margin: 0 0 6px;
}

.page-about .about-flow__d {
  max-width: 36em;
  margin: 0;
  color: var(--graphite);
}

.page-about .about-flow__tail {
  margin-top: 28px;
  font-size: 0.9375rem;
  color: var(--mist);
}

.page-about .about-flow__tail a {
  color: var(--glacier-500);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* 月度节奏三块 */
.page-about .about-archive {
  list-style: none;
  margin: clamp(32px, 4vw, 48px) 0 0;
  padding: 0;
  display: grid;
  gap: 24px;
  grid-template-columns: 1fr;
}

.page-about .about-archive__item {
  display: grid;
  gap: 8px;
  padding-top: 18px;
  border-top: 2px solid var(--ink-green);
}

.page-about .about-archive__k {
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--ink-green);
}

.page-about .about-archive__t {
  font-family: var(--font-head);
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--glacier-900);
  margin: 0;
}

.page-about .about-archive__item p {
  margin: 0;
  color: var(--graphite);
}

.page-about .about-archive__note {
  margin-top: clamp(32px, 4vw, 48px);
  padding: 22px 24px;
}

.page-about .about-archive__note p {
  margin: 0;
  max-width: 40em;
  color: var(--glacier-900);
}

/* 内容伙伴 */
.page-about .about-partners__intro {
  margin-top: 22px;
  max-width: 38em;
}

.page-about .about-partners {
  list-style: none;
  margin: clamp(28px, 3.5vw, 44px) 0 0;
  padding: 0;
  display: grid;
  gap: 18px;
  counter-reset: none;
}

.page-about .about-partners__item {
  display: grid;
  grid-template-columns: 46px 1fr;
  gap: 0 18px;
  align-items: baseline;
  padding: 16px 0;
  border-top: 1px solid var(--glacier-300);
}

.page-about .about-partners__item p {
  margin: 0;
  max-width: 38em;
  color: var(--graphite);
}

.page-about .about-partners__no {
  font-size: 0.8125rem;
  color: var(--prayer-orange);
}

.page-about .about-partners__tail {
  margin-top: 24px;
  font-size: 0.9375rem;
  color: var(--mist);
}

.page-about .about-partners__tail a {
  color: var(--glacier-500);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* 三件坚持 */
.page-about .about-hold {
  list-style: none;
  margin: clamp(32px, 4vw, 48px) 0 0;
  padding: 0;
  display: grid;
  gap: 26px;
}

.page-about .about-hold__item {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 4px 18px;
}

.page-about .about-hold__no {
  font-size: 0.875rem;
  color: var(--prayer-orange);
  grid-row: 1 / span 2;
  padding-top: 4px;
}

.page-about .about-hold__t {
  font-family: var(--font-head);
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--glacier-900);
  margin: 0;
  grid-column: 2;
}

.page-about .about-hold__item p {
  margin: 6px 0 0;
  max-width: 38em;
  grid-column: 2;
  color: var(--graphite);
}

.page-about .about-hold__tail {
  margin-top: 34px;
  font-size: 0.9375rem;
  color: var(--mist);
}

.page-about .about-hold__tail a {
  color: var(--glacier-500);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about a:focus-visible,
.page-about summary:focus-visible,
.page-about [tabindex]:focus-visible {
  outline: 2px solid var(--prayer-orange);
  outline-offset: 2px;
}

/* 移动端与窄屏 */
@media (max-width: 960px) {
  .page-about .about-rail {
    position: static;
    padding: 0 0 18px;
    border-left: none;
    border-bottom: 1px solid var(--glacier-300);
    min-width: 0;
  }

  .page-about .about-rail .rail__list {
    display: flex;
    flex-wrap: nowrap;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 6px;
    scrollbar-width: thin;
  }

  .page-about .about-rail__item {
    flex: 0 0 auto;
  }

  .page-about .about-rail__link {
    display: flex;
    align-items: baseline;
    gap: 6px;
    padding: 8px 14px;
    border-left: none;
    border: 1px solid var(--glacier-300);
    border-radius: 999px;
    background: var(--snow-white);
  }

  .page-about .about-rail__link[aria-current] {
    border-color: var(--prayer-orange);
    background: var(--prayer-orange-100);
  }
}

@media (max-width: 640px) {
  .page-about .about-shell {
    padding-bottom: 96px;
  }

  .page-about .about-axis {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-flow__step {
    grid-template-columns: 36px 1fr;
    gap: 0 14px;
  }

  .page-about .about-partners__item {
    grid-template-columns: 36px 1fr;
    gap: 0 12px;
  }

  .page-about .about-hold__item {
    grid-template-columns: 34px 1fr;
    gap: 4px 14px;
  }
}

@media (min-width: 720px) {
  .page-about .about-archive {
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 1ms !important;
    animation-duration: 1ms !important;
  }

  .page-about .about-axis__node::before,
  .page-about .about-rail__link {
    transform: none !important;
  }
}