.page-about {
  --about-axis: rgba(192, 138, 46, .38);
  --about-gap: 48px;
}

/* ============ 右侧装饰进度线 ============ */
.page-about .about-rail {
  display: none;
}

@media (min-width: 1025px) {
  .page-about .about-rail {
    display: block;
    position: fixed;
    right: 22px;
    top: 50%;
    transform: translateY(-50%);
    width: 1px;
    height: 180px;
    background: var(--line-gold);
    z-index: 4;
    pointer-events: none;
  }
}

.page-about .about-rail__fill {
  display: block;
  width: 1px;
  height: 100%;
  background: var(--c-red);
  transform-origin: top center;
  transform: scaleY(1);
}

@supports (animation-timeline: scroll()) {
  .page-about .about-rail__fill {
    animation: about-rail-scale linear both;
    animation-timeline: scroll(root block);
  }
}

@keyframes about-rail-scale {
  from { transform: scaleY(0); }
  to { transform: scaleY(1); }
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  padding-block: 72px 56px;
  overflow: hidden;
  background: var(--c-butter);
}

.page-about .about-hero__media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.page-about .about-hero__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .5;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(102deg, rgba(247, 241, 228, .97) 0%, rgba(247, 241, 228, .88) 46%, rgba(247, 241, 228, .58) 100%);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 2;
}

.page-about .about-hero__title {
  font-family: var(--font-serif);
  font-size: 32px;
  font-weight: 600;
  line-height: 1.32;
  letter-spacing: .01em;
  color: var(--c-ink);
  margin: 18px 0 0;
  max-width: 20ch;
}

.page-about .about-hero__lede {
  font-size: 16px;
  line-height: 1.9;
  color: var(--c-ink);
  margin: 20px 0 0;
  max-width: 60ch;
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 36px 0 0;
  padding: 22px 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 16px;
  border-top: 1px solid var(--line-gold);
}

.page-about .about-fact__num {
  display: block;
  font-family: var(--font-serif);
  font-size: 28px;
  font-weight: 600;
  line-height: 1.15;
  color: var(--c-red);
  font-variant-numeric: tabular-nums;
}

.page-about .about-fact__label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

/* ============ 主体网格 ============ */
.page-about .about-body {
  background: var(--c-butter);
}

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

/* ============ 侧边章节索引 ============ */
.page-about .about-index {
  display: none;
}

.page-about .about-index__title {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--c-gold);
  margin: 0 0 12px;
  font-weight: 500;
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-index__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
  text-decoration: none;
  transition: color .25s var(--ease), padding-left .25s var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--c-red);
  padding-left: 4px;
}

.page-about .about-index__num {
  flex: none;
  font-family: var(--font-serif);
  font-size: 13px;
  color: var(--c-gold);
  font-variant-numeric: tabular-nums;
}

/* ============ 章节画板 ============ */
.page-about .about-chapter {
  padding-bottom: 64px;
  margin-bottom: 64px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-chapter:last-child {
  padding-bottom: 0;
  margin-bottom: 0;
  border-bottom: 0;
}

.page-about .about-chapter__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 16px;
}

.page-about .about-chapter__index {
  flex: none;
  font-family: var(--font-serif);
  font-size: 36px;
  font-weight: 600;
  line-height: 1;
  color: var(--c-gold);
  opacity: .5;
  font-variant-numeric: tabular-nums;
}

.page-about .about-chapter__title {
  font-family: var(--font-serif);
  font-size: 23px;
  font-weight: 600;
  line-height: 1.42;
  color: var(--c-ink);
  margin: 0;
}

.page-about .about-chapter__lede {
  font-size: 16px;
  line-height: 1.9;
  color: var(--c-ink);
  margin: 0 0 32px;
  max-width: 62ch;
}

.page-about .about-chapter__more {
  margin: 32px 0 0;
}

.page-about .about-inline-link {
  color: var(--c-red);
  text-decoration: none;
  border-bottom: 1px solid rgba(140, 31, 40, .38);
}

.page-about .about-inline-link:hover,
.page-about .about-inline-link:focus-visible {
  border-bottom-color: var(--c-red);
}

/* ============ 时间脉络 ============ */
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 6px 0 6px 24px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: var(--about-axis);
}

.page-about .about-timeline__item {
  position: relative;
  padding-bottom: 30px;
  transition: transform .3s var(--ease);
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c-butter);
  border: 1px solid var(--c-gold);
  transition: background .25s var(--ease), border-color .25s var(--ease), transform .25s var(--ease);
}

.page-about .about-timeline__item:hover::before,
.page-about .about-timeline__item:focus-within::before {
  background: var(--c-red);
  border-color: var(--c-red);
  transform: scale(1.25);
}

.page-about .about-timeline__item:hover {
  transform: translateX(4px);
}

.page-about .about-timeline__stage {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--c-gold);
  margin: 0 0 6px;
  font-weight: 500;
}

.page-about .about-timeline__title {
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--c-ink);
  margin: 0 0 8px;
}

.page-about .about-timeline__text {
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
  margin: 0;
  max-width: 58ch;
}

/* ============ 团队 ============ */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
}

.page-about .about-team__figure {
  margin: 0;
  aspect-ratio: 3 / 2;
}

.page-about .about-team__text {
  font-size: 15px;
  line-height: 1.9;
  color: var(--c-ink);
  margin: 0 0 14px;
}

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

.page-about .about-team__roles {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  grid-column: 1 / -1;
}

.page-about .about-role {
  background: var(--c-stone);
  padding: 22px 20px 26px;
}

.page-about .about-role__num {
  font-family: var(--font-serif);
  font-size: 26px;
  font-weight: 600;
  line-height: 1.1;
  color: var(--c-gold);
  margin: 0 0 10px;
  font-variant-numeric: tabular-nums;
}

.page-about .about-role__name {
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--c-ink);
  margin: 0 0 8px;
}

.page-about .about-role__text {
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
  margin: 0;
}

.page-about .about-role:first-child {
  background: var(--c-lapis);
}

.page-about .about-role:first-child .about-role__num {
  color: var(--c-gold);
}

.page-about .about-role:first-child .about-role__name {
  color: var(--c-white);
}

.page-about .about-role:first-child .about-role__text {
  color: var(--on-dark);
}

/* ============ 整理流程 ============ */
.page-about .about-flow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
}

.page-about .about-flow__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-flow__step {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 0 14px;
  padding: 18px 0;
  border-top: 1px solid var(--line);
}

.page-about .about-flow__step:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .about-flow__num {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--c-gold);
  margin: 0;
  font-variant-numeric: tabular-nums;
}

.page-about .about-flow__name {
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--c-ink);
  margin: 0 0 6px;
}

.page-about .about-flow__text {
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
  margin: 0;
}

.page-about .about-flow__figure {
  margin: 0;
  aspect-ratio: 4 / 3;
}

/* ============ 承接规模 ============ */
.page-about .about-scale__stats {
  list-style: none;
  margin: 0 0 32px;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line-gold);
}

.page-about .about-scale__stat {
  background: var(--c-butter);
  padding: 20px 18px 22px;
}

.page-about .about-scale__num {
  font-family: var(--font-serif);
  font-size: 36px;
  font-weight: 600;
  line-height: 1.1;
  color: var(--c-red);
  margin: 0 0 8px;
  font-variant-numeric: tabular-nums;
}

.page-about .about-scale__unit {
  font-size: 17px;
  font-weight: 600;
  margin-left: 4px;
  color: var(--c-red-deep);
}

.page-about .about-scale__label {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  margin: 0;
}

.page-about .about-scale__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-scale__item {
  padding: 20px 0 20px 18px;
  border-left: 1px solid var(--line-gold);
  margin-bottom: 4px;
}

.page-about .about-scale__name {
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--c-ink);
  margin: 0 0 8px;
}

.page-about .about-scale__text {
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
  margin: 0;
  max-width: 60ch;
}

/* ============ 合作生态 ============ */
.page-about .about-partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.page-about .about-partners__text {
  font-size: 15px;
  line-height: 1.9;
  color: var(--c-ink);
  margin: 0 0 14px;
}

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

.page-about .about-partners__aside {
  padding: 22px 20px;
  background: var(--c-stone);
  border-left: 2px solid var(--c-gold);
}

.page-about .about-partners__aside-label {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--c-gold);
  margin: 0 0 10px;
  font-weight: 500;
}

.page-about .about-partners__aside-text {
  font-family: var(--font-serif);
  font-size: 17px;
  line-height: 1.7;
  color: var(--c-ink);
  margin: 0;
}

/* ============ 后续节奏 ============ */
.page-about .about-next {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
}

.page-about .about-next__line {
  background: var(--c-stone);
  padding: 22px 20px 26px;
}

.page-about .about-next__line:nth-child(2) {
  background: var(--c-butter);
}

.page-about .about-next__line-tag {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--c-gold);
  margin: 0 0 10px;
  font-weight: 500;
}

.page-about .about-next__line-title {
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--c-ink);
  margin: 0 0 10px;
}

.page-about .about-next__line-text {
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
  margin: 0;
}

/* ============ 结尾行动区 ============ */
.page-about .about-closing {
  background: var(--c-butter);
}

.page-about .about-cta {
  padding: 36px 24px 40px;
}

.page-about .about-cta__title {
  font-family: var(--font-serif);
  font-size: 24px;
  font-weight: 600;
  line-height: 1.42;
  color: var(--c-white);
  margin: 0 0 16px;
  max-width: 26ch;
}

.page-about .about-cta__text {
  font-size: 15px;
  line-height: 1.9;
  color: var(--on-dark);
  margin: 0 0 26px;
  max-width: 62ch;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
}

/* ============ 平板及以上 ============ */
@media (min-width: 721px) {
  .page-about .about-hero {
    padding-block: 96px 72px;
  }

  .page-about .about-hero__title {
    font-size: 42px;
    max-width: 22ch;
  }

  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-chapter__index {
    font-size: 46px;
  }

  .page-about .about-chapter__title {
    font-size: 28px;
  }

  .page-about .about-team {
    grid-template-columns: 5fr 7fr;
    gap: 36px;
    align-items: start;
  }

  .page-about .about-team__roles {
    grid-template-columns: 1.3fr 1fr 1fr;
    margin-top: 16px;
  }

  .page-about .about-flow {
    grid-template-columns: 7fr 5fr;
    gap: 40px;
    align-items: start;
  }

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

  .page-about .about-partners {
    grid-template-columns: 7fr 5fr;
    align-items: start;
    gap: 32px;
  }

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

  .page-about .about-cta {
    padding: 52px 44px 56px;
  }

  .page-about .about-cta__title {
    font-size: 30px;
  }
}

/* ============ 桌面 ============ */
@media (min-width: 1025px) {
  .page-about {
    --about-gap: 72px;
  }

  .page-about .about-body__grid {
    grid-template-columns: 180px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-index {
    display: block;
    position: sticky;
    top: 92px;
  }

  .page-about .about-chapter {
    padding-bottom: 88px;
    margin-bottom: 88px;
  }

  .page-about .about-hero__title {
    font-size: 50px;
  }

  .page-about .about-chapter__title {
    font-size: 31px;
  }

  .page-about .about-chapter__lede {
    font-size: 17px;
  }
}

/* ============ 动效收敛 ============ */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__fill {
    animation: none;
    transform: scaleY(1);
  }

  .page-about .about-timeline__item,
  .page-about .about-timeline__item::before,
  .page-about .about-index__link {
    transition: none;
  }

  .page-about .about-timeline__item:hover {
    transform: none;
  }
}